How the curves in your spine could be causing you pain

Source: The Conversation – UK – By Dan Baumgardt, Senior Lecturer, School of Psychology and Neuroscience, University of Bristol

Although the spine is naturally slightly curved, certain health conditions can make these curves more extreme. RomarioIen/ Shutterstock

Over 60% of us will suffer from lower back pain at some point in our lives. Without question, it’s the leading cause of disability across the globe.

Your spine is comprised of 33 bones known as vertebrae, which are stacked one on top of the other. The resulting column is divided into five segments: cervical (in the neck), thoracic (at the same level as the chest), lumbar (at the level of the abdomen) and sacral (connecting with the pelvis). The fifth, the coccyx, is located at the very bottom of the spine (the tailbone) – and is very painful when injured.

The vertebrae are connected by multiple joints, including discs which allow the spine to move in multiple directions. Though we might think the spine should appear straight, it naturally curves forward and backwards so it can perform all of its important functions.

But many conditions can cause the spine to curve more than it should. This can not only lead to pain, but potentially a whole host of other health troubles too.

Dowager’s hump

The spine also supports the weight of the body, protects the spinal cord and helps the body to bend, flex and twist. The thoracic region attaches to the ribs and naturally curves backwards – this curve is known as the thoracic kyphosis.

But sometimes, the curve of the thoracic kyphosis becomes more accentuated and visible – often as a result of osteoporosis (where bones become weaker), age-related changes to the back muscles and vertebrae, or long-term poor posture.

A picture depicting a man's spine which is curved due to kyphosis.
Dowager’s hump tends to be more common in women.
CLIPAREA l Custom media/ Shutterstock

The medical name for this condition is hyperkyphosis, though it’s sometimes referred to as “dowagers hump” as it’s around two to four times more common in women.

A stooped posture with rounded shoulders (or “hunchback” appearance) is typically a sign of hyperkyphosis. In some cases, it may become so extreme as to impact breathing since the chest can’t inflate properly. It can also affect swallowing since the neck becomes more horizontal and the gullet potentially narrowed.

And of course pain and stiffness typically arise. This is a common theme for most patients with abnormal curvature of the spine, as the vertebrae lose their ability to move, and nerves arising from the spinal cord can become compressed.

Scoliosis

Another type of deformity that can occur in the spinal column affects not only how it bends forward and backwards, but also side-to-side.

Scoliosis occurs when the vertebrae either curve sideways, rotate in relation to each other, or collapse. This produces a variety of different deformities, ranging in size and severity.

The underlying causes of scoliosis are widespread. Sometimes bones can become deformed as a result of trauma, cancer or an infection (such as tuberculosis). Scoliosis can also be present from birth, or arise from neurological disorders in early years – such as cerebral palsy.

As well as back pain, patients may also notice postural signs as scoliosis evolves. Their shoulder blades or ribcage can stick out more, and clothes may fit differently on their body.

Slipped and fused spines

Individual vertebrae in any part of the spine can sometimes also become displaced as a result of trauma, wear and tear, or certain health conditions (such as osteoporosis). This means that instead of standing in a regular stack, a vertebra slips forward, and out of line. This condition is given the long and practically unpronounceable name, spondylolisthesis.

An x-ray depicting ankylosing spondylitis in the lower spine.
Spondylolisthesis can be very painful.
Suttha Burawonk/ Shutterstock

In doing so, this displacement can trigger nerve compression. If the sciatic nerve – the largest in the human body – gets compressed, it can lead to symptoms of sciatica. These are namely pain, pins and needles, or numbness in the back of the leg or buttock.

The vertebrae in the lower back can sometimes also fuse abnormally together. A condition called ankylosing spondylitis can trigger inflammation in the spinal joints and discs, which then harden over time. Another name for the condition is bamboo spine, since the now rigid and inflexible column resembles a tough stalk of bamboo.

Managing back pain

Managing these conditions – and the pain they cause – will depend largely on the size of the deformity and what has caused it in the first place. Even a small spinal deformity can be significant.

For scoliosis for instance, braces to correct the spine as it grows may work to manage small defects in younger patients. But corrective surgery is often required to fix larger deformities and those which don’t respond to bracing.

Taking account of posture and bone health can also help prevent developing a spinal problem later in life. Using exercise to build a strong back and shoulders and avoiding slouching are solid measures, too. Managing associated conditions such osteoporosis with diet, medication and resistance training can also help.

Surgical intervention may be required in other situations – for instance, to decompress nerves that have become trapped or squashed.

Your spine is truly an architectural wonder. It’s far from a straight and rigid column – and capable of more than you’d ever expect. But this unique structure can lend itself to problems, especially when natural curves become deformities. The age-old adage “strengthen your back, strengthen your life” is a motto we should all be regularly reminded of, and to seek medical advice accordingly should back pain arise.

The Conversation

Dan Baumgardt 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. How the curves in your spine could be causing you pain – https://theconversation.com/how-the-curves-in-your-spine-could-be-causing-you-pain-262815

Physical education is important for academic success – here’s how it benefits kids’ cognition

Source: The Conversation – UK – By Simon Cooper, Professor in Physical Activity and Health, Nottingham Trent University

Physical education has many academic benefits. Drazen Zigic/ Shutterstock

There were 45,000 fewer hours of physical education (PE) delivered in UK schools during the last academic year compared to 15 years ago. This is concerning, given how important PE and physical activity are not only for children’s physical health, but their cognitive health too. As the new school year begins, it’s essential that PE hours in UK schools aren’t further cut given its importance for academic success.

A large body of evidence shows that physical education has many benefits for kids’ brains – including for their concentration and learning in the classroom.

For instance, research conducted by me and my colleagues has shown that in year seven and eight pupils, PE lessons are more beneficial for cognitive performance than an academic, classroom-based lesson is. We specifically compared the effects of a games-based PE lesson (where the students played football) with a normal classroom lesson that covered a subjects including maths and geography.

Cognitive performance was assessed via a test called the Sternberg paradigm. This tests short-term memory by asking participants to remember up to five random letters (called “target” letters), and then indicate whether letters they are presented with are one of their target letters or not. Cognitive performance was tested 30 minutes before the lesson, immediately after the lesson and then 45 minutes post-lesson.

Cognitive performance was better following the PE lesson compared to the normal classroom lesson on both of the post-lesson tests. This shows that PE is particularly beneficial for working memory, an aspect of cognition important for reasoning, learning and problem solving.

However, the important factor here was the intensity of the physical activity. The cognitive benefits of PE were far more pronounced in the children who did more moderate-to-vigorous physical activity during the lesson than in those who did low-intensity physical activity.

Moderate-to-vigorous physical activity was defined as time spent with a heart rate greater than 64% of the child’s maximum. So in 11-12 year olds, a heart rate of greater than around 135 beats per minute. These effects were once again most pronounced for working memory.

Similarly, research has shown that when more intense physical activity is encouraged in PE lessons, children see greater cognitive benefits than they do during standard PE lessons.

A group of boys plays football outdoors.
The more intense the physical activity, the better it was for cognitive performance.
Master1305/ Shutterstock

These findings suggest that not only is PE important, but the intensity of that activity is important too.

Further evidence also suggests that when students are encouraged to participate more often during PE, it positively benefits both cognition and academic performance. These benefits were particularly seen in their maths-related skills.

Where physical education takes place is also important. Research by me and my colleagues compared an identical 60-minute basketball session performed indoors and outdoors in secondary school children. Cognitive performance was again tested before the lesson, just after the lesson and 45 minutes post-lesson.

The outdoor physical activity produced greater effects on cognition compared to indoor activity. This was true for a number of aspects of cognition, including attention, working memory and executive function (higher level, complex thinking which is positively associated with academic outcomes). This suggest that, where possible, PE should be conducted outdoors to maximise cognitive benefits.




Read more:
Physical activity is good for your concentration – here’s why


Numerous studies have also shown that a bout of physical activity has an immediate, positive effect on cognitive performance. And, this effect even translates to better academic performance in maths.

Long-term effects

When we consider the longer-term effects of physical activity, our research has also shown that children who are fitter display better cognitive performance compared to children who are less fit. This is true across all aspects of cognition.

Children who are more physically active daily also have better cognitive performance. Kids who completed a daily mile (15 minutes of outdoor walking, jogging or running) everyday for five weeks not only got fitter, but they also saw improved executive function. This daily mile was done on top of their regular PE classes, while the control group continued with their usual daily activities. This suggests that additional physical activity can enhance cognitive performance.

Despite the clear benefits that physical activity has on academic success, the number of PE hours delivered in schools has reportedly been falling since 2012. Physical education in schools ultimately helps children learn. Its place and importance in the curriculum must be valued – and further cuts must be avoided.

The Conversation

Simon Cooper receives funding from the Waterloo Foundation, Rosetrees Trust, Stoneygate Trust and Education Endowment Foundation.

ref. Physical education is important for academic success – here’s how it benefits kids’ cognition – https://theconversation.com/physical-education-is-important-for-academic-success-heres-how-it-benefits-kids-cognition-260872

Why the National Gallery is creating a public panel to help shape its future

Source: The Conversation – UK – By Rebecca Starr, Lecturer in History of Art, University of Leeds

What do you expect to see when visiting the National Gallery in London? A neatly curated collection of landscape painting? Or a selection of the gallery’s must-see highlights – a veritable who’s-who of art history?

Both are reasonable expectations – but why? What does this tell us about the purpose and priorities of the National Gallery? This is a question underpinning NG Citizens, a recently announced initiative which sees the National Gallery promising to put people from across the UK “at the heart of its decision-making”.


This article is part of our State of the Arts series. These articles tackle the challenges of the arts and heritage industry – and celebrate the wins, too.


Launching this autumn, NG Citizens will form a citizens’ assembly of 50 participants chosen by a civic lottery. Building on the gallery’s previous efforts co-creating projects with its target audiences, NG Citizens is “a culture-shaping step” designed to ensure the gallery remains “relevant, inclusive and genuinely reflective of the public we serve”, according to Jane Knowles, the gallery’s director of public engagement.

So why now? The National Gallery is not struggling to attract people. Its latest figures show that last year, there were more than 4.7 million visitors to the London gallery and its touring displays – an increase of almost 10% from 2023.

Having recently celebrated its bicentenary, the National Gallery is keen to secure its position in the UK’s cultural landscape for another 200 years. With this in mind, NG Citizens is central to the gallery’s plans for the future.

These emphasise the need to demonstrate that it is a “national institution at the heart of national life”. This aspiration is supported by the creation of a new national learning service which aims to share the gallery’s collection with as wide an audience as possible.

Given the increasing international erosion of equality, diversity and inclusion (EDI)-related work, NG Citizens is a response to the UK museum sector’s wider commitment to access and inclusion. Museums and galleries are responding to this in several ways, from showcasing the work of marginalised, often-overlooked communities to amplifying the voices and experiences of staff, and publicising strategies for accountability.

Paving the way

This, however, isn’t the first time galleries and museums have sought public input – regional institutions have already been paving the way for NG Citizens.

In 2024, Nottingham’s New Art Exchange launched the Voice Assembly. Tasked with “shaping the future of art and culture in a meaningful, citizen-led manner”, Voice became the first initiative of its kind in which a cultural institution integrated a citizen assembly as part of its permanent leadership.

NG Citizens also draws inspiration from the timely work of Birmingham Museums Citizens’ Jury. Last year, this pioneering project saw Birmingham Museums invite 30 of the city’s residents to engage directly with the decision-making processes that will help to reshape the future of the group’s activities.

Over a series of six sessions, participants worked together to reimagine how the city’s cultural institutions can play a sustainable and meaningful role in public life. All those involved agreed that museums should provide experiences that are educational and improve knowledge. There was overwhelming agreement, too, that the city’s museums should welcome and inspire people of all ages and backgrounds, not just be spaces for an educated elite.

Yet these points have already raised concerns, including questions surrounding the intention of NG Citizens. While initially praising the scheme, UK museums consultant Maurice Davies has questioned whether the gallery is actually changing the way things are run, or if NG Citizens is simply a more sophisticated form of audience research.

Further concerns have been raised by critics worried over the extent to which the initiative will affect the content and purpose of the National Gallery’s collections and displays. For example, Evening Standard columnist Melanie McDonagh has questioned whether NG Citizens undermines the gallery’s reputation, describing it as “an awful idea” while arguing that “the point of the gallery is not to solicit the opinions of an uninformed public”.

Such concerns prompted swift responses from the National Gallery, reassuring critics that NG Citizens will not be directly involved with the selection of artworks and curation of exhibitions.

Why NG Citizens will be consulted on the gallery’s future purpose but not involved in curatorial decisions remains unclear. Perhaps reimagining the curatorial model of “experts” selecting works for public display, based on connoisseurship and notions of taste, will be the task for future groups of NG Citizens.

Is it the case, then, that the National Gallery is playing catch-up with both regional museums and industry research? For those engaged with museum and heritage studies, the question of audience engagement and participation is nothing new.

Research groups and institutions across the UK are continually exploring methods of collaboration to assess how co-production can improve public engagement.

There is still work to be done to ensure that UK museums and galleries offer fair and equal access to all members of society. However, I believe NG Citizens presents an exciting opportunity to put the public at the centre of the National Gallery’s approach to future working practices.

The gallery’s initial aim is to ask NG Citizens to reconsider its role in public life. Through opening this revered institution to more democratic modes of thinking and audience collaboration, perhaps soon a reasonable question to ask people will be: “What would you like to see at the National Gallery?”


Looking for something good? Cut through the noise with a carefully curated selection of the latest releases, live events and exhibitions, straight to your inbox every fortnight, on Fridays. Sign up here.


The Conversation

Rebecca Starr 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 the National Gallery is creating a public panel to help shape its future – https://theconversation.com/why-the-national-gallery-is-creating-a-public-panel-to-help-shape-its-future-264210

How unexploded bombs cause environmental damage – and why climate change exacerbates the problem

Source: The Conversation – UK – By Sarah Njeri, Lecturer in Humanitarian and Development Studies, SOAS, University of London

Daria Yehorova / Shutterstock

There are a record number of conflicts raging around the world – from Ukraine and Gaza to Sudan and Myanmar. Alongside their devastating human toll, these conflicts are all wreaking havoc on the environment.

One of the key ways war leads to environmental harm is by leaving behind unexploded weaponry. Since the start of Russia’s full-scale invasion in 2022, Ukraine has become the most landmine-contaminated country in the world. By January 2024, roughly 25,000 sq km of agricultural land there was estimated to have been contaminated with landmines and other so-called explosive remnants of war.

The contamination of Ukrainian farmland – alongside the physical damage from exploded mines – has contributed to a sharp decrease in agricultural activity, with wheat production in Ukraine falling by 41% between 2021 and the end of 2024. Ukraine has historically been one of the world’s largest agricultural exporters.

The damage wars are causing to land is also occurring at a time when climate change is driving land degradation. Rising temperatures, increased aridity and the intensification of extreme weather events are leading to reduced soil fertility and desertification. This often compounds the impact of unexploded mines and bombs on the land.


Wars and climate change are inextricably linked. Climate change can increase the likelihood of violent conflict by intensifying resource scarcity and displacement, while conflict itself accelerates environmental damage. This article is part of a series, War on climate, which explores the relationship between climate issues and global conflicts.


The human toll from explosive remnants of war is quite visible, as the number of deaths resulting from unexploded mines and bombs can be traced. In April 2024, for example, the Ukrainian government reported that landmines and other unexploded ordnance had accounted for more than 1,000 civilian casualties since the start of Russia’s invasion.

But the impact of explosive remnants on the land is less immediately apparent. Research in Cambodia, which was bombed extensively by the US military during the Vietnam war (1955-1975), suggests that unexploded ordnance continues to harm agricultural productivity there today.

Many of the bombs that landed on soft and highly fertile land failed to detonate. They continue to render the land hazardous. Due to the danger of unexploded bombs, many Cambodian farmers avoid using tractors and other agricultural techniques that could increase agricultural production.

Studies also show that explosive remnants of war affect soil quality. Unexploded bombs and landmines can leak heavy metals and toxic waste into the soil, polluting land and water. In rare cases, contaminants from a landmine have been detected up to 6km away from the initial explosion site.

People clearing mines from a field in the Kyiv region of Ukraine.
People clearing mines from a field in the Kyiv region of Ukraine.
home for heroes / Shutterstock

The methods for clearing unexploded ordnance can contribute to land degradation, too. Heavy demining equipment can damage fertile top soil and contribute to erosion. Some methods of disposal, such as controlled detonations, can also release contaminants into the soil.

Research on soil quality in the Halgurd-Sakran National Park in north-eastern Iraq, a region that has seen decades of armed conflict, show evidence of the release of hazardous metals such as lead, cadmium and arsenic into the soil following demining activities.

These contaminants pose significant risks both to local ecosystems and human health through direct contact and the contamination of water sources and food chains. There are also risks of contamination through inhaling or ingesting dust.

Climate change complications

Climate hazards such as droughts, floods and wildfires can exacerbate the impact of explosive remnants of war. Floods and heavy rainfall can unearth landmines and other unexploded ordnance, sometimes displacing them into areas previously considered safe.

High temperatures from heatwaves can also cause abandoned munitions to explode. Six different munition sites exploded across Iraq during scorching hot summers in 2018 and 2019, when temperatures regularly topped 45°C. Heatwaves were blamed for a similar arms dump explosion in Jordan in 2020.

At the same time, the presence of explosive remnants in the environment can hamper responses to climate events. In eastern Ukraine, for example, the heavy contamination of forests with landmines and tripwires prevented fire crews from responding effectively to wildfires in 2020. The fires damaged houses and killed seven people.

Similarly, unexploded bombs from the second world war have been detonated recently by wildfires in the North York Moors, UK. This increases the unpredictability of the fires, inevitably endangering the the lives of fire crews.

In Libya, Storm Daniel destroyed two dams in 2023 and subsequently caused flooding in large parts of the eastern city of Derna. The displacement of unexploded ordnance and ammunition stores caused by the flooding complicated recovery efforts.

Explosives experts also had to be deployed during the destructive floods in South Sudan in 2024 to assess whether land was safe for the relocation of displaced people.




Read more:
South Sudan floods: the first example of a mass population permanently displaced by climate change?


Abandoned cars and debris strewn across the flood-hit city of Derna.
The presence of explosive remnants of war complicated the response to Storm Daniel in Libya.
seraj.elhouni / Shutterstock

Climate disasters and environmental change can also prevent communities from benefiting from land that has been cleared of explosive remnants after the end of war.

In Angola, where there was a civil war between 1975 and 2002, drought has prevented farmers from planting crops in recently cleared fields. Increasing soil salinisation in Sri Lanka due to rising sea-levels has also affected the ability of farmers to plant rice in areas cleared of unexploded munitions.

Explosive remnants of war have a lasting impact, not only on human life but also the environment. Climate change is only making the threat more unpredictable and challenging to address.

It’s more important than ever that measures to restore land, tackle climate change and manage the impact of armed conflict – including explosive remnants of war – are addressed together rather than in isolation.

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. How unexploded bombs cause environmental damage – and why climate change exacerbates the problem – https://theconversation.com/how-unexploded-bombs-cause-environmental-damage-and-why-climate-change-exacerbates-the-problem-242535

What Xi Jinping hosting Modi and Putin reveals about China’s plans for a new world order

Source: The Conversation – UK – By Stefan Wolff, Professor of International Security, University of Birmingham

China’s president, Xi Jinping, has been busy on the diplomatic front. China has just hosted the largest annual summit of the Shanghai Cooperation Organisation (SCO), followed by an impressive military parade to mark the defeat of Japan in the second world war – all accompanied by key bilateral meetings with heads of state from like-minded countries. You could be forgiven for thinking Beijing is now the diplomatic capital of the world.

But look behind the facade of bonhomie on display in the Chinese capital, and the unity underpinning a new China-led global order looks a lot more fragile than Xi would have you believe.

The most important result of the SCO summit on August 31 and September 1 was not the fact that leaders adopted a lengthy communique and more than 20 joint statements on issues as diverse as artificial intelligence, green industries and international trade. What mattered most was the attendance of India’s prime minister, Narendra Modi, and the rapprochement between New Delhi and Beijing.

This was Modi’s first visit to China in seven years. That his country’s relations with China continue to improve was made clear by Modi’s positive assessment of his bilateral meeting with Xi (“fruitful”) and also their relationship, which he said is based on “mutual respect, mutual interest and mutual sensitivity”.

Another obvious indicator of China trying to pull India closer into the SCO fold was its unequivocal condemnation of the terror attacks in Pahalgam in Kashmir in April 2025. China’s earlier failure to do so had prevented India’s defence minister from signing a similar communique at a meeting of SCO defence ministers in June.

Modi’s attendance also provided the opportunity for him and Xi to demonstrate their continuing support for Russia’s president, Vladimir Putin. As far as alliances go, one between China, Russia and India would be a formidable factor in the remaking of the international order. But while there was an impressive display of solidarity between the three leaders, they are united by little more than their opposition to the current US-dominated order.

There was plenty of talk from Xi at the SCO summit about reforming the current system of international affairs – the latest blueprint of which is his Global Governance Initiative, which aims to transform the UN into a Beijing-led instrument. But the prospects of rapid change are limited.

China and India are both deeply integrated into the current international financial and economic system – as are most other SCO member states and partner countries. They may resent Donald Trump and his tariff policies but – with the partial exception of China’s dominance of the global rare-earth trade – they have little leverage.

Another problem for Xi is the fact his various forays into reshaping the international system are at best complementary. There is some overlap between the SCO and his other signature project, the Belt and Road Initiative (BRI). But while the BRI is global and focused primarily on extending China’s reach by economic means, the SCO is much more regional in outlook and focused on security.

Add to that the Brics (Brazil, Russia, India, China, South Africa) group, and China’s approach to remaking the international system begins to look less like a coherent strategy than a series of trial balloons – with even Xi unsure which will eventually pave the way to China’s global leadership role.

A final issue for Xi is that he is limited in his choice of partners. At the SCO summit in Tianjin, it was all about relations between China, Russia and India. Two days later at the victory parade in Beijing, the fledgling alliance between China, Russia and North Korea seemed to take centre stage. However, the absence of Modi from this event demonstrated that India does not want to be too closely associated with North Korea.

Xi has different options in how he pursues his challenge to the current world order – but some are mutually exclusive. Not everyone in his orbit is comfortable with all the political alignments the Chinese president chooses.

Antipathy to US-led order

This is not to say that China’s quest to replace the US as the global superpower is bound to fail. There is a logic to what Xi is doing. He is building a Chinese-dominated sphere of influence in Asia as a power base from which to reach for global hegemony.

But outside a small circle of similarly autocratic leaders, what has propelled this project so far is less the appeal of a China-led international system than dissatisfaction with the existing liberal international order. And while this dissatisfaction predates the current incumbent of the White House, it has been aggravated over the first six months of Trump’s second term.

More than two decades of careful recalibration of US relations with India, including drawing New Delhi into an alliance pushing back against China in Asia, appear recently to have been sacrificed at the altar of Trump’s insatiable vanity.

When India failed to acknowledge his claim to have mediated in its row with Pakistan after the Pahalgam terror attack and declined to join Pakistan in nominating Trump for a Nobel peace prize, his response was to rekindle relations with Pakistan and impose punitive tariffs on India.

Simultaneously, Trump’s wholly misguided America-first foreign policy has undermined the very relationships in Europe and Asia that underpinned the liberal international order and secured US dominance. At least his latest insight – that China, Russia and North Korea “conspire against the United States” – gives a glimmer of hope for America’s concerned allies in the west that the US president will change course in how he deals with Beijing, Moscow and Pyongyang.

If Trump doesn’t recognise the value of his country’s allies in managing the challenge that China clearly poses to the US, Xi’s sphere of influence may quickly extend far beyond Asia. This could relegate the US to a second-order power confined to – but not necessarily secure in – a diminishing sphere of influence.

The Conversation

Stefan Wolff is a past recipient of grant funding from the Natural Environment Research Council of the UK, the United States Institute of Peace, the Economic and Social Research Council of the UK, the British Academy, the NATO Science for Peace Programme, the EU Framework Programmes 6 and 7 and Horizon 2020, as well as the EU’s Jean Monnet Programme. He is a Trustee and Honorary Treasurer of the Political Studies Association of the UK and a Senior Research Fellow at the Foreign Policy Centre in London.

ref. What Xi Jinping hosting Modi and Putin reveals about China’s plans for a new world order – https://theconversation.com/what-xi-jinping-hosting-modi-and-putin-reveals-about-chinas-plans-for-a-new-world-order-262244

How to help disabled and neurodivergent people flourish while working from home

Source: The Conversation – UK – By Christine Grant, Associate Professor (Research), Centre for Healthcare and Communities, Coventry University

Gorodenkoff/Shutterstock

Home-based working in the UK has been declining since the peak of the COVID pandemic – from 49% of the working population at its height to around 14% now.

While hybrid working is still increasing in popularity, attitudes persist among some employers that remote working reduces productivity, visibility and creativity. As a result, many workplaces are requiring a return to fully on-site working.

This approach, however, is not supported by research into hybrid working (a mix of working at home and on-site) which suggests productivity is not damaged and that it can also improve job satisfaction.

For many people who are disabled, neurodivergent or both, home-based working provides a real opportunity to gain – and retain – a job in a productive and supportive environment. Around 24% of the working-age population are disabled, with the employment rate among disabled people around 54%.

While disabled staff can request remote working as a reasonable adjustment, it can attract stigma. This is one reason why people may not always feel able to make this request, or say how much they would prefer to work from home. Some workers may fear repercussions like being overlooked for promotion or even losing their job.

I have studied the experiences of disabled and neurodivergent people who work from home, so I know how life-changing having a flexible job can be. One interviewee in my research told me: “I can sustain my productivity and, from my point of view, that means I can work better.”

Another said: “I don’t have to mask [attempt to hide autistic traits] at home. So there’s just a huge drop in … general anxiety and tension.”

Several large employers who took part in my study indicated that, while remote working was positive for many of their employees, there were downsides that needed to be managed. These include ensuring staff maintain their professional networks and social contacts, and discouraging working while unwell (presenteeism). Home working can intensify pressure to work while sick, and it may be harder to spot in a remote setting.

A toolkit for managers

Perhaps unsurprisingly, one of the key findings was that a supportive line manager was crucial for disabled and neurodivergent workers to make a success of remote working. Many managers, however, didn’t have enough knowledge or understanding of how to best to support each employee’s specific needs, so they couldn’t always offer appropriate guidance and advice.

With this in mind, I developed a toolkit for line managers to enable them to better support this community of workers. When good conversations happen between line managers and employees, solutions can be tailored to the person’s needs. The toolkit offers guidance to line managers on how to enable those conversations.

disabled woman working from home on her laptop with a walking aid beside her desk.
Successful remote working starts with good conversations between staff and line managers.
Monkey Business Images/Shutterstock

I make the case for remote working by setting out the benefits (including a more flexible workforce and more inclusive recruitment) for the organisation. The toolkit is designed to help managers recognise the ways in which home-based working can be positive for these workers, offering advice on how to reap the benefits while managing the downsides.

It also shares technical knowledge about disability and neurodivergence, such as how the UK Equality Act relates to this workforce, and how to approach the “reasonable adjustments” process (changes that an employer is legally obliged to make to ensure disabled staff are not at a disadvantage).

Managers these days often lead mixed teams of remote and on-site workers. To encourage effective remote working and productivity, my research has found that regular meetings and check-ins between line managers and home-working staff are important.

But sometimes it’s not enough for managers simply to level the playing field. People who are disabled, neurodivergent or both will benefit from tailored support in order to flourish in the workplace. They need to feel safe to disclose their conditions and needs, and to be themselves at work.

Remote working offers an opportunity to employ people who might not be able to work in a traditional office-based, “nine-to-five” environment. My research found that when key resources were in place, such as a conducive working environment, appropriate technology and a supportive line manager, this helped to build their self-confidence and autonomy.

It also helped them to manage their energy levels and self-care, which in turn supported better productivity, fewer absences and the ability to stay in work over the long term.

Employers should understand that the needs of this group of workers can unlock key strengths for their organisation – including diversity, staff retention and increased productivity. Remote working can present challenges for managers – but when managed well, it can also help them create a more flexible, inclusive and agile workplace.

The Conversation

Christine Grant receives funding from the UK Economic and Social Research Council as part of the Digital Futures at Work Research Centre (grant number ES/S012532/1) and from Coventry University’s ESRC Impact Acceleration Account.

ref. How to help disabled and neurodivergent people flourish while working from home – https://theconversation.com/how-to-help-disabled-and-neurodivergent-people-flourish-while-working-from-home-259183

La montée de l’appui à la souveraineté chez les jeunes au Québec, feu de paille ou vague de fond ?

Source: The Conversation – in French – By Éric Bélanger, Professeur en science politique, McGill University

L’été 2025 n’a pas seulement été chaud, il a électrisé la scène politique québécoise. Le Parti québécois (PQ) a fait élire un autre candidat lors d’une élection partielle dans Arthabaska en août, et des sondages récents laissent présager un regain de popularité pour la souveraineté, notamment chez les jeunes. Assiste‑t‑on à un renouveau souverainiste solide ou à une simple poussée estivale d’émotion politique ?

Avec 35 % des voix (contre 46 % pour le PQ), la défaite a été crève-cœur pour Éric Duhaime qui a perdu son second pari visant à se faire élire et à amener le Parti conservateur du Québec à l’Assemblée nationale. Elle aura été cependant l’occasion de se réjouir pour le chef du PQ Paul St-Pierre Plamondon.

Parallèlement, on constate un certain regain dans l’opinion publique alors que des sondages récents ainsi que des jeunes artistes comme Lou-Adriane Cassidy ou le rappeur kinji00 remettent la question de la souveraineté du Québec à l’ordre de jour.

Pour nous, cotitulaires de la Chaire de recherche sur la démocratie, le vivre-ensemble et les valeurs communes au Québec, et spécialistes de la politique québécoise et de l’opinion publique, cette dynamique mérite un regard approfondi. Nous l’examinons sous trois angles : la méthodologie des sondages, les motivations profondes du regain, et les précédents historiques.

Interroger les sondages : ce qu’ils disent… et ce qu’ils ne disent pas

Dans un premier temps, il importe de s’attarder à la dimension méthodologique des sondages cités dans les médias. Ces coups de sondes ont des limites bien réelles. D’abord, l’appui de 56 % des jeunes de 18-34 ans, mesuré par la firme CROP au début du mois d’août, ne correspond pas à une intention de vote à un éventuel référendum – où la réponse se résumerait à « Oui » ou « Non ». Il s’agit plutôt d’un appui exprimé sur une échelle en quatre points, allant de « très favorable » à « très défavorable » à l’idée de souveraineté.

En juin dernier, la firme Léger a quant à elle mesuré une hausse des intentions de vote en faveur du « Oui » dans la même tranche d’âge, s’élevant à environ 48 %.

Sans mettre en doute l’existence de cette évolution chez les jeunes, on n’en sait très peu sur la taille exacte et la provenance des échantillons qui ont été rejoints dans ces deux enquêtes ni sur la manière avec laquelle les deux firmes de sondage ont pondéré les réponses de ces jeunes à ces questions. Par exemple, le chiffre de 48 % chez Léger paraît reposer sur les réponses de 195 jeunes individus seulement. L’appui de ce même groupe d’âge à la souveraineté est d’ailleurs retombé à 42 % dans leur enquête suivante publiée au mois d’août. De manière générale, plus les échantillons sont petits, plus les opinions mesurées sont susceptibles d’être volatiles.

Enfin, on a déjà observé par le passé que les appuis à la souveraineté ont tendance à diminuer une fois le PQ porté au pouvoir. Ces appuis avaient par exemple reculé de 8 points de pourcentage en quelques mois seulement à la suite de la victoire de Pauline Marois en 2012. Ce phénomène peut être attribuable à l’ambivalence qu’entretiennent généralement les Québécois vis-à-vis le PQ : ils aiment l’idée que ce parti dirige le Québec mais ils entretiennent des réserves face à son option constitutionnelle. Il est donc ici important d’offrir une nuance quant aux « réelles » préférences politiques des jeunes personnes sondées.

Langue, culture, crises politiques : ce qui motive l’appui à la souveraineté

Dans un second temps, nos travaux de recherche portant sur l’appui à l’indépendance au Québec et ailleurs dans le monde, notamment en Écosse et en Catalogne, indiquent que c’est surtout la volonté de protéger sa langue ou de conserver sa culture qui alimentent l’intérêt pour cette option constitutionnelle.

Il y a ici lieu de se questionner sur le rapport à la langue française des jeunes interrogés. Quelle est réellement l’importance de cette langue pour eux ? Certains, notamment ceux qui consomment beaucoup de contenu sur les plates-formes numériques comme TikTok, sont plus près des préoccupations des vlogeurs français (voir l’étude de l’Institut de la statistique du Québec). Ces jeunes parlent français certes, mais leurs référents culturels sont beaucoup plus franco-français que québécois.

Par ailleurs, les recherches ont aussi montré que les griefs, stimulés par des crises politiques tels l’échec de l’Accord du lac Meech ou le scandale des commandites, sont parmi les facteurs qui font le plus augmenter les appuis à la souveraineté. Or, il n’y a pas, présentement, de tels griefs ou de telles crises qui soient clairement en place au Québec.

Le poids de l’histoire : les jeunes (presque) toujours en tête du mouvement

Dans un troisième temps, c’est en posant un regard historique qu’il est possible d’offrir un autre éclairage sur cette montée, même modeste, de l’appui à la souveraineté. Historiquement, ce sont les jeunes qui ont surtout appuyé l’idéal d’indépendance. Ce fut le cas tant au Québec qu’ailleurs, comme en Écosse. Il est donc cohérent que ce soit la jeunesse québécoise qui soit à l’avant-garde de ce regain de soutien pour la cause souverainiste.

C’est notamment ce qui a été observé dans les précédents regains d’intérêt pour la souveraineté (chez les baby-boomers durant les années 1970 ; dans une moindre mesure chez la génération X durant les années 1990). Avec le recul, on se rend compte que la réelle anomalie historique tient peut-être à la cohorte des millénariaux (les individus nés entre 1980 et 1995) qui a davantage boudé le mouvement souverainiste que les autres.

À la lumière de ces différents travaux, les causes actuelles de ce regain pour la souveraineté chez les jeunes sont donc loin d’apparaître claires. Verrons-nous un réel engouement pour le Parti québécois ou bien seulement un passage à ce parti en raison de la fatigue envers le gouvernement de la Coalition avenir Québec (CAQ) ?

Ces trois dernières années, le PQ a su tirer son épingle du jeu, profitant d’une période de turbulence pour le Parti libéral du Québec (PLQ) et Québec solidaire (QS), moins présents dans le débat public. Même s’il formait l’opposition officielle, le PLQ a été affaibli par une absence de chef permanent depuis 2022, comblée seulement en juin par l’élection de Pablo Rodriguez, ce qui a freiné son redéploiement politique. Quant aux membres et aux élus de QS, ils étaient trop occupés par leurs guerres intestines pour fonctionner ensemble et offrir une seule voix commune à l’Assemblée nationale et aux médias.

Et maintenant ?

Les jeunes ont presque toujours été attirés par la souveraineté. Cet attrait observé actuellement est-il lié à un rapport à l’avenir qui serait fondamentalement différent chez cette cohorte ? Se transformerait-il en appui réel dans l’urne à l’occasion d’un nouveau référendum ? Est-ce que les votes enregistrés dans les élections partielles étaient des votes de protestation ou bien un appui réel au PQ et à son option constitutionnelle ?

Nous avons des bémols. L’évolution de l’appui à la souveraineté demeure bien sûr à surveiller et à étudier.

La Conversation Canada

Éric Bélanger a reçu des financements du programme de Chaires de recherche du Québec (FRQSC)

Mireille Lalancette a reçu des financements du programme de Chaires de recherche du Québec (FRQSC)

ref. La montée de l’appui à la souveraineté chez les jeunes au Québec, feu de paille ou vague de fond ? – https://theconversation.com/la-montee-de-lappui-a-la-souverainete-chez-les-jeunes-au-quebec-feu-de-paille-ou-vague-de-fond-264227

Attacks on school boards threaten local democracy

Source: The Conversation – Canada – By Marianne A. Larsen, Professor Emerita, Faculty of Education, Western University

Elected school boards across Canada are increasingly threatened. Ontario Education Minister Paul Callandra recently said he is open to eliminating elected trustees altogether. This would would follow the lead of Nova Scotia and Québec, where they have already been abolished.

As a temporary measure, Ontario has taken over the role of elected trustees in five boards by appointing supervisors to oversee their finances and operations.

I’m an educational historian who has studied the comparative history of teaching and development of educational systems and an elected school board trustee for the Thames Valley District School Board (TVDSB), which the province recently put under supervision following an investigation of the TVDSB’s financial affairs.

I cannot comment here on the specifics of the TVDSB or any other school board.

The province says it put the TVDSB and other four boards under supervision to address growing deficits, strengthen accountability and, in the case of the other four boards, to restore financial stability.

However, researcher Joel Westheimer, professor of democracy and education, writes that Ontario is the latest province to “have signalled its intent to eliminate or weaken” elected school boards and put decision-making more firmly with the ministry.

“In reality,” he writes, “it’s a power-grab — and another step toward centralizing authority in order to sideline communities, parents and students.”

Based on my historical research, this article examines the broader history of provincial governments extending their control over democratically elected school boards.

Local democracy rooted in elected boards

Local democracy rooted in elected school boards has a long history in Canada going back more than 200 years. Education legislation in Nova Scotia in 1811, New Brunswick and Ontario (formerly Upper Canada) in 1816, Prince Edward Island in 1825 and Newfoundland in 1836 established elected school boards even before a country called Canada, with federal and provincial governments, existed.

Much has changed in school boards across Canada over the last two centuries. The powers and responsibilities of elected school board trustees have been eroded considerably. Current moves to restrict the powers of school board trustees are a part of a longer history of broadening government control over local communities.

Familiarity with local conditions

In Canada, each province/territory has its own educational system with a ministry/department that oversees the organization, delivery and assessment of education, and each province is divided into school board districts.

Board members (trustees) who are familiar with local conditions are elected by supporters within each district to represent their community’s interests and provide a liaison between electors and their provincial government.

My research on teachers shows that in early 19th century settler-colonial pioneer settings in North America, schooling was closely integrated into local community life.




Read more:
Reckoning with the history of public schooling and settler colonialism


Early emigrants to Upper Canada valued education for their children and, as a result, a variety of small schools emerged in local communities. In response, the British colonial government passed the first Common School Act in 1816 that provided each of the 10 school districts with 6,000 pounds annually to establish schools where there were at least 20 pupils.

Empowering local communities

The 1816 act also stated that when a schoolhouse was built, local communities were empowered to elect three “fit and discreet persons” to serve as trustees to manage their school.

Trustees had the authority “to examine into the moral character and capacity of any person willing to become a Teacher of such Common School” and subsequently nominate and appoint teachers on behalf of the community.

Trustees not only had the power to hire, pay and remove teachers, but also “to make Rules and Regulations for the good government” of the school and notify the District Board of Education about the books used and general state of the local school. By 1841, trustees were authorized to tax local inhabitants to supplement the government grant.




Read more:
Black History: How racism in Ontario schools today is connected to a history of segregation


State-controlled educational systems

Around the world throughout the late 18th and 19th centuries, governments began the work of building state-funded, public educational systems. Building standardized, state-controlled educational systems took place gradually as legislation was enacted to construct systems to educate the poor and working classes who did not have access to formal schooling. In colonial societies like Canada, building public educational systems was a part of the process of building a country.




Read more:
Truth before reconciliation: 8 ways to identify and confront Residential School denialism


The reasons governments got into the business of providing free education to the general populace included fear of social unrest, rising crime rates and the belief that government control of education would help create an obedient and moral Christian population.

Schooling underwent a gradual shift of being largely in the hands of local communities to being more under government control. This was the beginning of long process, still ongoing today, of centralizing educational authority at the expense of local autonomy and community, and the work of school board trustees.

Second World War and onwards

As Canadian historian Bruce Curtis has argued, building the educational state in Ontario in the 19th century necessitated eroding the close relationship between locally elected school board trustees and their communities.

A brick building with Canadian flag out front.
A former school building in Elora, Ont.
(Bill Badzo/Flickr), CC BY

That process continued during the post-Second World War period, as the organization and structures of schools boards were reformed to deal with the expansion and increasing complexity of educational systems.

This resulted in the amalgamation of many school boards. In Ontario, there were thousands of elected local school boards in the mid-19th century. Following many stages of amalgamation, the most significant being in the mid-1990s, the province has only 72 district school boards.

Loss of the local

As a result of school boards increasing in size alongside population growth and shrinking in number, the role of school board trustees has diminished. A report by the Education Improvement Commission in 1997 concluded because of 1990s-era educational reforms in Ontario, each trustee would represent more constituents over a larger area. They would therefore need to devote significant time to pulling their communities together to overcome the loss of their local board in favour of a district board.

The power to raise funds through local taxation, to determine teacher’s pay and working conditions and to determine what is and is not taught in local schools are no longer responsibilities of local school board trustees.

The Ontario government now aims to pass Bill 33, the Supporting Children and Students Act, which would substantially expand the education minister’s ability to investigate a board’s conduct, give directions and assume a board’s powers if those directions aren’t followed.

These moves are about enhancing government control over school boards and, according to educational researcher Sachin Maharaj, “part of the government’s ongoing bid to assert its own vision of schooling.”

Navigators and representatives

Such power plays have negative consequences for local democratic voices, public accountability and transparency and for schools.

Educational history sheds light on the close relations between early 19th-century elected school board trustees and their local communities. Over the last two centuries, governments have increased the number of constituents trustees serve and centralized powers once held by trustees.

But this has led to the severing of relations between local communities and elected school board trustees, which is neither good for grassroots democracy, nor for our schools, our students and their families.

The Conversation

Marianne A. Larsen 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. Attacks on school boards threaten local democracy – https://theconversation.com/attacks-on-school-boards-threaten-local-democracy-261895

Mars has a solid core, resolving a longstanding planetary mystery — new study

Source: The Conversation – UK – By Kevin Olsen, UKSA Mars Science Fellow, Department of Physics, University of Oxford

NASA

Scientists have discovered that Mars has an interior structure similar to Earth’s. Results from Nasa’s Insight mission suggest that the red planet has a solid inner core surrounded by a liquid outer core, potentially resolving a longstanding mystery.

The findings, which are published in Nature, have important implications for our understanding of how Mars evolved. Billions of years ago, the planet may have had a thicker atmosphere that allowed liquid water to flow on the surface.

This thicker atmosphere may have been kept in place by a protective magnetic field, like the one Earth has. However, Mars lacks such a field today. Scientists have wondered whether the loss of this magnetic field led to the red planet losing its atmosphere to space over time and becoming the cold, dry desert it is today.

A key property of the Earth is that its core has a solid centre and liquid outer core. Convection within the liquid layer creates a dynamo, producing the magnetic field. The field deflects charged particles ejected by the Sun, preventing them from stripping the Earth’s atmosphere away over time and leading to the habitable conditions we know and enjoy.

From residual magnetisation in the crust, we think that Mars did once have a magnetic field, possibly from a core structure similar to that of Earth. However, scientists think that the core must have cooled and stopped moving at some point in its history.

On the surface of Mars there is a tremendous amount of evidence that liquid water once flowed, suggesting more hospitable conditions in the past. The evidence comes in many forms, including dry lake beds with minerals that formed under water, or the dramatic valley networks carved by rivers and streams. However, the Martian atmosphere is thin today and the necessary amount of water is nowhere to be found.

Teams working with the seismometers on Nasa’s InSight Mars lander first identified the Martian core and determined that it was actually still liquid. Now, the new results from Huixing Bi, at the University of Science and Technology of China in Hefei and colleagues, show that there may also be a solid layer inside the liquid core.

The nature of the interior structure of Mars has been an intriguing mystery. Was it ever like Earth’s, with a dynamic liquid layer around a solid centre? Or did Mars’ smaller size prevent such a formation? How big must a planet be to gain the protection of a magnetic field, like Earth’s, and support a habitable climate?

To understand what happened, how Mars evolved, we need to understand Mars today. These questions about Mars’ atmosphere, water, and core have motivated several high profile Mars missions. While the Nasa Mars rovers, Spirit, Opportunity, Curiosity, and Perseverance have studied the surface mineralogy, the European Space Agency’s ExoMars Trace Gas Orbiter is studying the water cycle, Nasa’s Maven spacecraft is studying atmospheric loss to space, and Nasa’s InSight lander was sent to study seismic activity.

Insight
The Insight mission landed on Mars in 2018.
JPL-Caltech

In 2021, Simon Stähler, from ETH Zurich in Switzerland, and colleagues, published a seminal paper from the InSight mission. In it, they presented an analysis of the way that seismic waves pass through Mars from Mars quakes in the vicinity of InSight, through the mantle, through the core, and then reflecting off the other side of the planet and reaching InSight.

They detected evidence of the core for the first time and were able to constrain its size and density. They modelled a core with a single liquid layer that was both larger and less dense than expected and without a solid inner core. The size was huge, about half of Mars’ radius of 1,800 km, and the low density implied that it was full of lighter elements. The light elements, such as carbon, sulphur, and hydrogen, change the core’s melt temperature and affect how it could crystallise over time, making it more likely to remain liquid.

The solid inner core (610 km radius) found by Huxing Bi and colleagues is hugely significant. The very presence of a solid inner core shows that crystallisation and solidification is taking place as the planet cools over time.

The core structure is more like Earth’s and therefore more likely to have produced a dynamo at some point. On Earth, it is the thermal (heat) changes between the solid inner core, the liquid layer, and the mantle that drive convection in the liquid layer and create the dynamo that leads to a magnetic field. This result makes it more likely that a dynamo on Mars was possible in the past.

With Simon Stähler and co-authors reporting a fully liquid core and Huxing Bi and colleagues reporting a solid inner core, it might seem as if there will be some controversy. But that is not the case. This is an excellent example of progress in scientific data collection and analysis.

The findings will help guide scientists towards a better understanding of Mars’ evolution as a planet.
JPL-Caltech

Competing models of Mars

InSight landed in November 2018 and its last contact with Earth occurred in December 2022. With Stähler publishing in 2021, there is some new data from InSight to look at. Stähler’s model was revised in 2023 by Henri Samuel, from the Université Paris Cité, and colleagues. A revised core size and density helped reconcile the InSight results with some other pieces of evidence.

In Stähler’s paper, a solid inner core is specifically not ruled out. The authors state that the signal strength of the analysed data was not strong enough to be used to identify seismic waves crossing an inner core boundary. This was an excellent first measurement of the core of Mars, but it left the question of additional layers and structure open.

For the latest study in Nature, the scientists achieved their result through a careful selection of specific seismic event types, at a certain distance from InSight. They also employ some novel data analysis techniques to get a weak signal out of the instrument noise.

This result is sure to have an impact within the community, and it will be very interesting to see whether additional re-analyses of the InSight data support or reject their model. A thorough discussion of the broader geological context and whether the model fits other available data that constrain the core size and density fit will also follow.

Understanding the interior structure of planets in our Solar System is critical to developing ideas about how they form, grow, and evolve. Prior to InSight, models for Mars that were similar to Earth were investigated, but were certainly not favoured.

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. Mars has a solid core, resolving a longstanding planetary mystery — new study – https://theconversation.com/mars-has-a-solid-core-resolving-a-longstanding-planetary-mystery-new-study-264325

Pourquoi y a-t-il encore des éboulements rocheux alors que des solutions de protection existent ?

Source: The Conversation – in French – By Marion Bost, Directrice technique Géotechnique, PhD, HDR, experte internationale en mécanique des roches, Cerema

Une zone d’habitation sécurisée par des écrans de filets à Foix, dans l’Ariège. Marion Bost, Fourni par l’auteur

En montagne, les éboulements sont fréquents. Leurs conséquences peuvent être dramatiques au dessus des routes et des installations humaines, de plus en plus présentes en montagne. Comment nous protéger ?


Le 20 août dernier, un éboulement rocheux dans la descente des Egratz vers Chamonix (Haute-Savoie) sur la RN 205 a causé un accident mortel. Début février 2025, à une semaine des vacances d’hiver, la route nationale 90 était bouchée à l’entrée de la vallée de la Tarentaise (Savoie). Le trafic ferroviaire entre Paris et Milan a été interrompu pendant plus d’un an et demi… à cause d’un éboulement rocheux fin août 2023. Ces évènements nous rappellent que ces phénomènes naturels constituent encore aujourd’hui une forte menace dans les territoires de montagne.

Entre 1900 et 2021, sur le territoire national, on recense 18 éboulements rocheux qui ont fait des victimes. Mais une route coupée peut aussi conduire à des effets que l’on imagine moins spontanément : une rupture dans l’accès aux soins, dans le transport transfrontalier de personnes et de marchandises et aussi, bien sûr, l’accès aux stations de ski – secteur qui représente plus de 10 milliards d’euros de chiffre d’affaires annuel en France.

Comment se protéger des éboulements rocheux ?

Pour protéger les personnes et les biens, des structures de protection « passives » peuvent être mises en œuvre, soit en interceptant les blocs rocheux lors de leur propagation dans la pente, soit en les déviant. Les merlons comme les filets métalliques peuvent servir aux deux actions selon leur conception.

Un bloc de 4 mètres cubes arrêté par un écran de filets à Notre-Dame-de-Briançon sur la route nationale 90 en Savoie.
Fourni par l’auteur

Ainsi les écrans souples de filets sont constitués de nappes de filets déformables maintenues par des poteaux et par des câbles, qui sont fixés au sol par des ancrages. Des systèmes de dissipation d’énergie (appelés « freins ») sont disposés sur les câbles ou au niveau des ancrages pour limiter les efforts dans la structure et dissiper l’énergie cinétique d’impact du bloc.

Les écrans de filets peuvent arrêter des blocs avec une énergie d’impact jusqu’à 12 000 kilojoules, ce qui correspond à des blocs de 15 mètres  cubes, soit l’énergie d’un bloc du volume d’un SUV circulant à la vitesse de 90 kilomètres par heure.

Les merlons sont des structures massives en élévation par rapport au terrain naturel, constituées de matériaux de remblai, comme le sol en place, renforcés ou non par différentes technologies (géosynthétique, armature métallique, pneu…).

Selon leur conception, la capacité d’arrêt des merlons peut être supérieure à celle des écrans de filets métalliques, et atteindre plusieurs dizaines de milliers de kilojoules, soit plus de trois à quatre blocs de quinze mètres cubes à 90 kilomètres par heure.

immense construction en béton devant une montagne
Merlon pour le chantier EDF à Livet-Gavet dans l’Isère.
Marie-Aurélie Chanut, Fourni par l’auteur

La solution des écrans souples de filets est cependant souvent privilégiée en zone de montagne, car elle nécessite peu d’emprise au sol et peut être installée en forte pente grâce à des hélicoptères.

Comment conçoit-on ces ouvrages de protection ?

Comme tout ouvrage du génie civil, un écran de filets doit être dimensionné. Pour cela, il faut recenser sur le terrain les blocs potentiellement instables et évaluer s’ils sont susceptibles de s’ébouler. Dans un second temps, nous réalisons des simulations numériques pour estimer l’énergie et la hauteur de passage de chaque bloc, afin de définir l’endroit dans la pente où positionner l’ouvrage de protection et avec quelles caractéristiques. Ensuite, un produit existant sur le marché permettant de remplir ces conditions est choisi.

des blocs au dessus d’une route en montagne
Des blocs arrêtés par les écrans de filets souples installés au-dessus de la route nationale 90 en Savoie.
Marie-Aurélie Chanut, Fourni par l’auteur

Notons que la capacité d’arrêt de certains produits marqués CE a été testée par des essais d’impact réalisés en grandeur réelle. De plus, après l’installation des structures sur le terrain, des inspections détaillées et un entretien des ouvrages permettent d’assurer le niveau de service attendu pendant la durée de vie de chaque ouvrage, soit au minimum vingt-cinq ans en atmosphère peu corrosive.

La conception d’un écran de filets de protection contre les chutes de blocs est cependant complexe. Elle doit tenir compte d’un comportement dynamique et non linéaire de l’ouvrage sous l’impact d’un bloc. Ce type d’ouvrage favorise de grands déplacements au sein de la nappe de filets, qui limitent la concentration des efforts. Certains composants, essentiellement les freins, se déforment alors de façon irréversible.

un bloc tombe dans un filet. Simulation numérique
Simulation numérique d’un bloc rocheux impactant un écran de filets.
Jibril Coulibaly et collaborateurs, C2ROP, Fourni par l’auteur

Ainsi depuis les années 1970, la communauté scientifique et technique se mobilise pour améliorer la compréhension du comportement de ces ouvrages sous sollicitation dynamique.

Quand les filets ne remplissent pas leur mission

Malgré ces efforts pour améliorer la fiabilité des écrans de filets, ces ouvrages peuvent encore être mis en défaut aujourd’hui.

Par exemple, un éboulement exceptionnel peut dépasser la sollicitation prise en compte lors du dimensionnement. Ce fut le cas lors de l’éboulement déjà cité sur la RN90, pendant lequel trois blocs de plus de 10 mètres cubes ont percuté à grande vitesse, estimée à 28 mètres par seconde, et presque simultanément, un écran de filets neuf de capacité d’arrêt maximale égale à 8 000 kilojoules (c’est-à-dire pouvant arrêter un seul bloc de 8 mètres cubes chutant à plus de 100 kilomètres par heure).

L’impact d’un bloc rocheux de forme tranchante présentant une vitesse de rotation significative ou encore un impact au niveau des câbles de haubanage ou des extrémités de l’ouvrage peuvent être également plus sévères que l’impact dans les conditions des essais en vraie grandeur de certification du produit.

Écrans de filets 8 000 kilojoules, installés dans le versant de Ponsérand pour sécuriser la RN 90 en Savoie.
Laurent Dubois, Fourni par l’auteur

Enfin, des erreurs de montage ou encore le vieillissement de certaines pièces métalliques par corrosion peuvent avoir une incidence sur la capacité d’arrêt de l’ouvrage tout au long de sa durée de vie.

Des enjeux qui évoluent

Les enjeux (bâtiments, infrastructures de transports…) situés dans les fonds de vallée des régions montagneuses sont de plus en plus vulnérables. En effet, les dernières décennies ont vu l’augmentation du trafic et de la pression foncière, en lien notamment avec l’essor du tourisme de montagne. En conséquence, les besoins en ouvrages de protection performants et fiables ne font qu’augmenter.

Des stratégies territoriales de protection doivent donc être mises en place. Mais les coûts élevés de mise en œuvre et d’entretien obligent à définir et à prioriser les actions de sécurisation vis-à-vis du risque rocheux.

The Conversation

Marion Bost a reçu des financements de la Direction Générale de la Prévention des Risques du Ministère de la Transition écologique, de la Biodiversité, de la Forêt, de la Mer et de la Pêche.

Laurent Dubois travaille avec des entreprises de travaux construisant des merlons ou des écrans de filets sur les chantiers et dans le cadre de groupes de travail méthodologiques ou de normalisation.

Marie-Aurélie Chanut a reçu des financements de IREX.

ref. Pourquoi y a-t-il encore des éboulements rocheux alors que des solutions de protection existent ? – https://theconversation.com/pourquoi-y-a-t-il-encore-des-eboulements-rocheux-alors-que-des-solutions-de-protection-existent-261712