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April 10, 2026

What will it take to get ships going through the Strait of Hormuz again?

Source: The Conversation – Global Perspectives – By Jennifer Parker, Adjunct Professor, Defence and Security Institute, The University of Western Australia; UNSW Sydney

Wednesday’s ceasefire announcement by President Donald Trump, linked to Iran reopening the Strait of Hormuz, prompted immediate optimism shipping would quickly resume. It didn’t.

The following morning, traffic remained minimal. A handful of vessels, largely linked to Iran, made the transit. But most of the ships waiting in the Gulf stayed put. Iran announced shortly afterwards that it would effectively close the strait because of Israel’s attacks on Lebanon.

The reality is the strait was never closed. Framing the issue as “open” or “closed” misses the point.

Ships are not being physically blocked. They are being deterred.

Over recent weeks, Iran has demonstrated both the capability and intent to target commercial shipping. Attacks and credible threats against vessels have driven daily transits down from around 130 to just a handful. Until that risk changes, ships will not return in meaningful numbers.

So what can be done to turn this around?

Both walking and talking

The ceasefire declarations have added to the uncertainty rather than resolved it.

Washington has asserted that the strait is open.

Tehran’s messaging has been more ambiguous, including references to requiring vessels to inform Iranian authorities before transiting.

Some interpret this as a precursor to attempts to exert control over the waterway through a toll.

This ambiguity matters. Shipping is a commercial activity driven by risk calculations. Operators and crews will not move on the basis of political statements, particularly when recent experience suggests those statements may not hold.

The importance of reassurance

In practice, restoring traffic through the strait will likely occur in two phases.

The first is reducing the threat. That can occur through military means, diplomacy, or a combination of both, but it must materially degrade Iran’s ability and willingness to target shipping.

The second is reassurance.

Even if Iran’s attacks on civilian shipping stop as a result of the ceasefire, shipping will not immediately return. Confidence has been shaken and will take time to rebuild.

A credible reassurance effort would include limited naval escorts, at least initially. It’s notable the US did not move immediately to demonstrate confidence in the ceasefire by escorting US flagged and crewed commercial vessels out of the Gulf.

That would have sent a clear signal to industry, helped restore confidence in transits and undercut subsequent Iranian claims that ships require approval from its armed forces.

Given Iran’s interest in maintaining the ceasefire, it would have been unlikely to challenge ships under US naval protection. The US hesitation has instead created space for Iran to entrench its position, pushing vessels closer to its coastline and reinforcing its ability to shape how the strait is used.

An effective reassurance campaign would also involve a broader international presence to provide surveillance, information-sharing and rapid response capability. The international community should move quickly to establish this. Its very establishment would help restore confidence in transits.

We have seen this model before. The International Maritime Security Construct, established in 2019 following Iranian attacks in the Gulf of Oman, focused on transparency, coordination and reassurance rather than large-scale convoy operations.

I served as the construct’s Director of Plans in 2020. A similar, but more effective, approach is likely to be required again. It is not a silver bullet, but reassurance is layered, and this would at least provide the clarity and communication shippers need.

Diplomacy will also matter. Clear, coordinated messaging from the international community, backed by explicit economic consequences for any renewed attacks on merchant shipping, will be essential to rebuilding confidence.

The question of tolls

There has also been speculation about whether Iran might seek to impose a toll on vessels transiting the strait.

The legal position here is clear. The Strait of Hormuz is an international strait under the United Nations Convention on the Law of the Sea. Ships enjoy the right of transit passage through the strait. Charging vessels for passage would cut directly against that principle and set a dangerous precedent for other strategic waterways.

There are early signs Iran is testing the boundaries. Reports of radio calls warning vessels they require approval to transit, and suggestions that ships should notify Iranian authorities before transiting, point to an attempt to exert greater control over the strait.

That should be resisted.

Allowing a toll, or even limited restrictions, to take hold in the Strait of Hormuz would have far-reaching consequences, undermining the central principle of maritime trade: freedom of navigation. Regardless of Donald Trump’s flippant comments, the international community is unlikely to accept any enduring Iranian toll system.

If Iran attempts to pursue one, it should face clear economic consequences, including sanctions.

Questions remain about whether mines have been laid in or near the strait. Even the suggestion adds to uncertainty and reinforces the need for a coordinated international response, including transparent assessments of the threat environment.

A clear, public assessment from the international community on whether the strait has in fact been mined would go a long way. It should be an early priority for any coalition effort.

The bottom line

Ultimately, shipping will return to the Strait of Hormuz not when it is declared open, but when it is assessed to be safe enough.

That will require a sustained period without attacks, a visible international effort to secure the waterway, and clear signalling that the rules governing international straits will be upheld.

Until then, the ships will wait.

Jennifer Parker 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 will it take to get ships going through the Strait of Hormuz again? – https://theconversation.com/what-will-it-take-to-get-ships-going-through-the-strait-of-hormuz-again-280275

April 10, 2026

Five warning signs that rivers are polluted – even when they look clean

Source: The Conversation – UK – By Jess Neumann, Associate Professor of Hydrology, University of Reading

After months of relentlessly miserable weather for most of the UK, spring brings renewed enthusiasm for spending time outdoors hiking, wild swimming, paddling or on walks.

Millions of people visit lakes and riversides every year. Yet with constant, and sadly necessary, reminders about sewage and water pollution, it’s not surprising that people are increasingly worried about whether the water they see is safe.

Cocktails of contaminants created by sewage systems, agricultural pollutants and urban runoff are currently at the forefront of public, scientific and regulatory focus.

Not one UK river was free from chemical contamination, and only 14% were classified as having “good ecological status” at the last assessment.

In 2024 alone, raw and partially treated sewage was discharged in to watercourses for more than 3.6 million hours. With around 15,000 sites regularly discharging effluent, in addition to ongoing inputs from agriculture, transport and other industries, the 2025 results due to be published this year are not expected to show significant improvement.

Given this, many people who spend time around rivers want to know how to identify pollution.

A sewage pipe pours water into a river. — diegorayaces/Shutterstock

It’s worth remembering that pollution isn’t always visible.

River contaminants take many forms. Some, like oil sheens, excrement, sanitary products and fly-tipping are visible and often odorous. Others such as nutrients including phosphates and nitrates, heavy metals, microplastics, and chemicals like ammonia and Pfas “forever chemicals” are invisible to the naked eye.

Pollutants may enter rivers from points such as discharge pipes, but also from farmland or roads, making them difficult to trace. Assuming you’re not armed with specialist pollution testing kit, identifying contamination often relies on observing indirect signs. Here are five indicators to look out for along with the conditions in which they are most likely to appear:

1. Sewage fungus

Look out for a pungent, gelatinous, fuzzy carpet along the river bed, often found downstream of sewage outfall pipes.

Although not technically a fungus, these slimy, brownish-grey growths of bacteria and microorganisms thrive in nutrient-rich waters. Sewage fungus reduces oxygen levels in water, suffocating and physically smothering aquatic life.

2. Algal blooms

Look out for thick green mats or scum on the surface of the water, often looking like pea soup or spilled paint in green, blue-green, or brownish-black colours. Odours may be musty, earthy or grassy.

Algae is a natural part of aquatic ecosystems. Warm and dry weather combined with overloads of nitrogen and phosphorus nutrients, can trigger excessive algal growth. Algal blooms block light and use up available oxygen during their decomposition in a process known as eutrophication. The effects of algal blooms, especially blue-green algae can be catastrophic to aquatic life, and toxic to humans and pets.

3. Murky water

Look out for colours that are different to what’s expected, and cannot be easily explained by what you know about the local landscape.

Sewage tends to present as grey, cloudy or milky, sometimes accompanied by bubbles, foam and a foul odour. Green or blue-green is indicative of algal blooms. Unusual colours like orange, red, yellow, or black may suggest industrial leaching or chemical dumping. Soil erosion can cause large quantities of suspended solids giving rivers a murky brown appearance that reduces light penetration and can suffocate organisms.

However, not all colours are a cause for concern. Heavy rain will naturally suspend particles and transport sediments giving rivers a temporary murky appearance. Local geology and soils may result in tea-coloured water caused by high iron content, or oily sheens caused by aerobic iron-fixing bacteria in boggy areas. You may even spot harmless dyes used by water companies and contractors to trace drainage leaks and misconnections.

4. White foam

Look out for bright white or milky-grey foam that doesn’t easily disperse. It is often accompanied by a perfume, soapy or detergent-like smell.

Man-made foam from sewage, detergents, fire-fighting activities, pesticide runoff and industrial processes causes oxygen depletion in water. They can contain noxious forever chemicals known to cause serious health conditions in humans and wildlife.

Understanding river foam requires a discerning eye – not all foam is bad. Natural foam, while aesthetically unpleasant, can be formed by decaying leaves and plants. White-to-brown in colour, natural foam smells earthy or slightly fishy. It can collect in large clumps and is common on windy days, following heavy rain and in turbulent and nutrient-rich waters. In the absence of other environmental impacts like dead fish, algal blooms, or obviously stagnant water, natural foam is rarely problematic.

5. Aquatic life

Look out signs of distress including fish gasping at the surface, dead fish, or unusual behaviour from animals that live in and around the river.

Pollution causes a decrease in dissolved oxygen, which alongside drought and temperature extremes are leading causes of fish deaths and wildlife distress.

The presence of species such as kingfishers, water voles, frogs and riverflies indicate a cleaner river environment. A prolonged and noticeable absence of wildlife using the river is a concerning sign.

Interpreting the signs and taking action

Even with these indicators, identifying pollution is not always clear-cut. Many of these signs can overlap or have natural explanations, making it difficult to draw firm conclusions based on appearance alone.

To build a clearer picture, it’s important to consider additional information. For example:

Are there unusual smells?
Is there a visible discharge point nearby?
Have there been reports of people or animals becoming ill after contact with the water?
Has there been recent sewage discharge in the area?
In England, water companies provide near real-time data on sewage discharges through monitoring systems. However, these show how long spills occur, not the volume or concentration of pollutants, so they offer only part of the picture.

If you suspect serious pollution, it should be reported immediately to the relevant environmental authority.

While the current state of our waterways is concerning, understanding the signs of pollution and taking action are important steps toward improvement. Being well informed could help avoid turning your day out on the water into an unpleasant and potentially unhealthy experience for you and your friends and family.

Jess Neumann works at the University of Reading as an Associate Professor of Hydrology. She is a trustee of River Mole River Watch, a water quality charity who work with, advise, and receive funding from environmental and conservation organisations and agencies, water companies, commercial services, local authorities and community groups. She is a Director of the UK Chapter for the International Association for Landscape Ecology.

– ref. Five warning signs that rivers are polluted – even when they look clean – https://theconversation.com/five-warning-signs-that-rivers-are-polluted-even-when-they-look-clean-279881

April 10, 2026

Children going through family courts face increased risk of self-harm, new research finds

Source: The Conversation – UK – By Amanda Marchant, Research Assistant & PhD Candidate in Mental Health, Swansea University

Family courts step in at some of the hardest moments in a child’s life, when parents separate or when there are concerns about their safety.

We already know that children involved in care proceedings are more likely to self-harm. But most children who come into contact with family courts are there because of disputes between parents, not safeguarding concerns. Until now we have known comparatively little about these children or what happens to them after court proceedings end.

For the first time, our research tracked self-harm over time in these children. We found that children who go through the family courts, whether because of parental separation or welfare concerns, are more likely to self-harm than those who do not.

This doesn’t mean the courts themselves are causing harm. This increased risk is more likely linked to the circumstances that lead families to court in the first place. Family courts are an often-missed opportunity to offer help.

We analysed anonymised family court records alongside routinely collected health data for more than 700,000 children between 2011 and 2018. Around 17,000 had been involved in private cases – usually disputes over finances or living arrangements after separation. Another 5,500 were involved in public cases, where local authorities step in over concerns about a child’s welfare.

The risk of self-harm was about twice as high after private cases and more than three times as high after public ones.

Exterior of a building with the sign Family and Youth Court — Children involved in family court were more likely to self-harm than those with no court contact.
Diana Parkhouse/Shutterstock

Previous research shows that families in contact with courts often face challenges beyond the courtroom. They are more likely to live in deprived areas and to experience mental or physical health problems, in both caregivers and children. These factors are already known to increase the risk of self-harm in young people.

Historically, people designing services for families have not always had enough data to guide the decisions made in family courts. Evidence now shows elevated risks not just of self-harm but for a range of adverse outcomes, including depression, anxiety and poorer educational attainment. Yet family courts receive far less public attention than many other issues affecting young people.

A warning sign we shouldn’t ignore

Self-harm is relatively common in adolescents. Most young people who self-harm do not go on to die by suicide. However, it is one of the clearest signals of distress and one of the strongest risk factors for suicide. This makes early identification and support especially important.

Children who come into contact with family courts should be a priority for support.

Parental separations are common. Many children experience them and their effects can be underestimated and downplayed because of that. Around one in ten separating families turn to family courts to resolve disputes, often as a last resort because of the financial and emotional costs. It may also reflect high levels of conflict between parents.

The decisions made during these proceedings can be life changing for children. Where families reach the point of involving family courts, we should ensure that support is available for the whole family, especially for children.

Family courts are in a unique position. They come into contact with children and families, with complex and intersecting needs, at important moments that have the potential to shape the rest of their lives.

We believe that contact with the courts should be seen as an opportunity to identify the needs of these families and offer practical, timely support to children and their families. This might include wider networks such as schools, community services and primary care or to provide clearer pathways to specialist mental health support where needed.

Decisions made in family courts have the potential to shape children’s lives at critical moments. These moments should be seen as signals of need, not just legal milestones. If we act on them, we have a real chance to support children at the point they need it most.

Amanda Marchant receives funding from Health and Care Research Wales (HCRW).

Ann John receives funding from MRC, Health and Care Research Wales and NIHR.

– ref. Children going through family courts face increased risk of self-harm, new research finds – https://theconversation.com/children-going-through-family-courts-face-increased-risk-of-self-harm-new-research-finds-278263

April 10, 2026

May elections: what five politics experts are looking out for

Source: The Conversation – UK – By Jonathan Tonge, Professor of Politics, University of Liverpool

On May 7 2026, voters in England, Scotland and Wales will head to the polls. Parliamentary elections are taking place in the devolved Welsh Senedd Cymru and Scottish Parliament, and local elections for over 4,850 councillor roles could have huge implications for local governments throughout England. With all to play for, we asked five experts to tell us what they will be keeping their eye on.

Can Reform compete across the UK?

Jonathan Tonge, Professor of Politics, University of Liverpool

The 2026 elections will reveal whether Reform UK will peak as an English nationalist party, or if they can compete as a genuine nationwide force. Last year’s local elections confirmed that Reform can seriously harm the Conservatives. This year, contests are across councils held mainly by Labour, making the English elections about Reform’s threat to Keir Starmer’s party.

Nigel Farage’s party, which currently has eight MPs, has led opinion polls in England since May 2025, when it won the highest vote in English local elections. Reform took control of ten councils (from a starting point of zero), and gained nearly 700 new councillors. Of these, eight were county council gains from the Conservatives, with another taken from a Liberal Democrat-led coalition. The tenth gain was from Labour in the only metropolitan borough contested, Doncaster.

Reform’s likely gains in English councils aren’t guaranteed elsewhere in the UK however. The party’s polling in Scotland is around ten percentage points behind what it is in England. It may be that Reform is battling Labour for second place, while the Scottish National Party (SNP) continues to dominate.

Reform’s polling in Wales is higher (in the mid-to-high-20% range) but again, the real battle is with Labour for runner-up, as Plaid Cymru seems set to top the poll.

Scottish Parliament, Senedd Cymru, Birmingham Council dome — Elections in the Scottish Parliament, Senedd Cymru, and local councils across England will drastically reshape the UK’s political landscape this May.
Wangkun Jia/shutterstock, trabantos/shutterstock, Juan Garcia Hinojosa/Shutterstock

Local results could force tricky coalitions

Alex Nurse, Reader in Urban Planning, University of Liverpool

Local elections are often concerned with local issues – think potholes and bin collections. Councils are also obliged by law to spend a lot of their time and budget on initiatives like adult social care, but these issues are often lost in the broad brush strokes of election campaigns.

It will be interesting to see how the ascendant Greens and Reform present their vision for local government, and what compromises they make to win over local voters. In the recent Gorton and Denton byelection, Green candidate Hannah Spencer made scarce mention of the environment and instead focused heavily on the cost of living and the broader social contract. Similarly, Reform’s promise to mimic the US Department of Government Efficiency (Doge) following the 2025 elections came up short after its newly elected councillors found local authorities already cut to the bone from years of austerity.

I’ll also be watching to see how the fragmented opinion polls translate into council seats. While we might be expecting a wipeout for Labour and the Conservatives, it remains to be seen how many councils the other parties will win wholesale, and where there will be situations of no overall control, requiring tricky coalition building. This might involve attempts to form a coalition of like-minded councillors, as seen in Bristol. However, the reality is often that parties attempt to go it alone, by entering minority government and living vote by vote, as seen in places like Sheffield or Wirral.

Challenges to inclusive Scottish identity

Murray Leith, Professor of Political Science and Director of the Centre for Migration, Diaspora, Citizenship and Identity, University of the West of Scotland

The SNP has long predicated its sense of national identity on a civic and inclusive
Scottishness. Its message throughout the past 19 years has been that anyone who believes in Scotland can be Scottish. While other parliamentary parties have challenged and attacked myriad SNP platforms and policies in the last two decades, none disagree with this political elite consensus.

However, this agreement has not been as duly accepted by people in Scotland who
are less accepting of incomers and migrants (from the rest of the UK and beyond) claiming Scottish identity. Scotland has shifted from an emigrant nation to an immigrant nation in recent years. Without immigration, Scotland’s population would have shrunk. While migration policy remains reserved to Westminster, it looms large in the minds of voters – so much so, that the SNP has made devolving immigration power to Scotland one of its 14 key manifesto pledges.

Reform UK is openly challenging this inclusive and welcoming political consensus. In his first speech, Malcolm Offord, Reform’s Scottish leader spoke of strangers and uncontrolled immigration destabilising communities. Given recent polling and the possibility that Reform may be the official opposition in the next Scottish parliament, the SNP may soon be facing an opposition that proposes a less inclusive vision of Scottishness.

A potentially huge turnover on councils

Hannah Bunting, Senior Lecturer in Quantitative British Politics and Co-director of The Elections Centre, University of Exeter

In the English local elections, I’m keeping an eye out for how many incumbents lose their seats. We know that voters are disillusioned with the two main parties and looking for alternatives. Last year in the 2025 locals, and in many council byelections since, less than 40% of Labour and Conservative incumbents were re-elected. According to our data at The Elections Centre, this figure hasn’t dropped below 70% since 1973.

There are also many more vacancies this year compared to 2025, with Labour defending half of the nearly 5,000 up for grabs, and the Conservatives defending another quarter of them. If this rate of losses continues, we are going to see thousands of new councillors elected, with huge implications for local governments.

Two Labour strongholds, Sunderland and Barnsley, are currently polling in favour of Reform, as is Walsall, which has been held by the Conservatives since 2004. The Greens are making headway in the inner boroughs of London, and councils with “no overall control” may be more common than ever in the capital after these contests. Labour has the furthest to fall, and all eyes will be on how many gains Reform and the Greens make, alongside how many areas turn to the Liberal Democrats as an alternative.

A proportional system in the Senedd

Anwen Elias, Reader in Politics, Aberystwyth University

Changes to the way Welsh voters elect the Senedd – a proportional system where one vote is cast for a political party’s list of candidates across 16 new constituencies – will require parties to campaign very differently compared to previous elections. The extent to which they can adapt will affect how they perform.

Under the previous electoral system, most Senedd members (40 out of 60) were elected under first-past-the-post, with the rest elected through proportional regional lists. There was an incentive to focus attention and resources on key seats where a political party had the best chances of winning. Under the new system parties will need to gain support from across Wales if they want to ensure a strong presence in the Senedd.

This requires a different kind of campaign strategy and organisation, which is likely to be especially challenging for parties with fewer resources. Within constituencies – some of which are huge – political parties will have to mobilise activists in areas where historically they might not have had a much presence or electoral support. Parties with the available resources for a coordinated national campaign and a strong media, and social media, presence will have a clear advantage under this new system.

Alex Nurse receives funding from the Economic and Social Research Council.

Anwen Elias receives funding from the Economic and Social Research Council.

Hannah Bunting receives funding from the Economic and Social Research Council (ESRC).

Murray Leith has previously received funding from the European Union and the Scottish Government. He is a member of the Electoral Reform Society.

Jonathan Tonge 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. May elections: what five politics experts are looking out for – https://theconversation.com/may-elections-what-five-politics-experts-are-looking-out-for-279260

April 10, 2026

I was in Georgia in the late 1980s: I observed how tradition survived harsh Sovietisation and rapid transformation

Source: The Conversation – UK – By Karina Vamling, Professor emerita of Caucasus Studies, Malmö University

Begos’ Friends by Georgian painter Niko Pirosmani, painted in the 1910s. At a keipi or festive supra, the tamada holds a kantsi (horn) and introduces a toast.
Wikiuka/Wikimedia

When Soviet president and Communist party secretary Mikhail Gorbachev introduced the policies of perestroika (reconstruction) and glasnost (openness) in the mid-1980s, it marked the beginning of cautious reforms of the Soviet Union. Georgia, or the Georgian Soviet Socialist Republic, to give it its full name at the time, was on the periphery of the union.

Far from Moscow, it lay hidden on the other side of the Caucasus mountain range on the edge of the Black Sea. As a doctoral candidate in linguistics on a research grant to Tbilisi University, I spent one year living there, between 1987 and 1988. I was conducting research on the Georgian language.

Travel at the time was very difficult, and could only happen via Moscow. I did not return to Sweden for the duration of my stay. In the recent publication, We Witnessed the Soviet Break-Up: Five Scandinavian Researchers on the Final Years of the USSR, Seen From the Caucasus, I detail how this gave me a front-row seat from which to observe the speed at which society was shifting – and how language was key to that transformation. I also observed how old cultural traditions had endured despite decades of Communist propaganda and harsh Sovietisation.

Rapid transformation

The May Day parade was long one of the key moments in the Soviet calender. I witnessed the last time it was held in central Tbilisi, in 1987. People were carrying red flags. Banners declaiming “Glory to the Communist party” and “Glory to our multinational Soviet Fatherland” were draped on the main buildings.

Next year, however, the national movement across the republic was pushing for a free Georgia. In November 1988, many took part in a hunger strike in front of the Georgian parliament against changes in the constitution that would reduce the rights of the Georgian republic. Protesters wanted what they termed the “Russification of Georgia” to come to an end.

Georgian society was multiethnic and multilingual, counting Russians and Georgians alongside Armenians, Azerbaijanis, Abkhaz, Ossetians, Greeks and many others. Georgian was the main language within the Georgian education system as well as in broadcasting and the press and, technically, according to Article 6 of the Constitution of Soviet Georgia recognised as the republic’s official language. However, during the Soviet period, Russian speakers could easily live and work in Georgia without knowing Georgian: Russian was the lingua franca for inter-ethnic communication within the republic and the Soviet Union at large.

As a non-Indo-European language, Georgian boasts its own script and a written history that dates back to the 5th century AD. It is a cornerstone of the Georgian identity. Within the wider push for greater political freedom, Georgians now fought for the implementation of the constitutional status of Georgian. This included increased demands for knowledge of Georgian in workplaces and administration, while also investing in teaching Georgian as a second language.

Efforts were made to develop Georgian terminology in technology, science and other fields where Russian had been dominant. Citizens who had little or no knowledge of Georgian were under pressure to learn.

Enduring traditions

Despite decades of Sovietization, social and family life remained underpinned by old patriarchal traditions.

During my time in the country, I was welcomed with more openness and engagement, and less suspicion, than during the three years I had spent in Moscow. I experienced the extent to which hospitality was an ancient Georgian virtue. “A guest is a gift from God,” local people would say.

Georgians were proud of their cuisine and ancient wine production. When a guest entered a home, the dinner table would quickly transform into a feast, what is know as a “supra”. This came with its own specific structure and rules. The man of the house would assume the role of toastmaster (tamada), and the wife and female members of the family would prepare and serve the food. They would be called in from the kitchen for a toast in honour of the women. In some traditional families, the men would sit at one end of the table, and the women and children at the other.

These traditions were discernible across the different cultural communities within Georgia. Tensions at the time were growing between Tbilisi and the central Soviet authorities in Moscow, and within Georgia itself, with minorities in the autonomous entities of Abkhazia and South Ossetia.

In the summer of 1989, the first violent Abkhaz-Georgian clashes took place. I was on a day trip, travelling from Sokhumi, the capital of the Autonomous Republic of Abkhazia, to a wedding in a small town called Zugdidi in the Megrelia region when violence broke out. Unable to return to Sokhumi as planned, I ended up spending one week with a family on the outskirts of the town.

Being there was like stepping back in time. The household was run by a young woman called Tsira, who, as a widow, dressed all in black. According to tradition, she would remain in black for the rest of her life. Her eldest son, who was 12-13 years old at the time, appeared to be seen as the man of the house.

Tsira’s neighbours came round and my friends from Sokhumi sat with them, discussing the conflict in Megrelian, the local language. Tsira prepared food, chicken and maize porridge over an open fire in a small wooden hut in the yard. Smoked cheese hung from the ceiling.

At one point, we visited the cemetery. Tsira sat on a stone bench by a black marble bust of her husband while relatives and guests sat around the grave. The women brought out Soviet champagne and food. I observed how toasting and eating bread dipped in wine were important in a ritual of honour and remembrance.

These religious practices showed how, within the official atheism of Soviet society, Georgian Orthodox traditions persisted – as they still do today. Another such religious practice common in Georgia during Soviet times was to hold a commemorative supra 40 days after a person had passed away. During this period, the men were not supposed to shave. The 40 days are considered the time it takes for the soul to reach heaven and God.

In 1990, I heard the crowd shouting “occupiers, occupiers” in front of the general staff of the Caucasian Military District in Tbilisi. The newly adopted Soviet law, dubbed the “law of non-secession” made the idea that the Soviet Union might break up feel a utopian dream. And yet it did, merely a year later. Georgia declared independence from the Soviet Union on April 9 1991 and the split was finalised on December 26 with the dissolution of the USSR.

In the intervening decades, the ethnopolitical conflicts that were fomenting during this early post-Soviet period have only deepened, not least following the Russo-Georgian war of 2008. Today, they remain largely unresolved and the situation in Georgia, highly volatile.

The Georgian language, however, has reclaimed the media, education and the streets. Russian has been replaced by English among the young generation of Georgians who do not carry this Soviet heritage.

Karina Vamling received funding from the Swedish Institute, Åke Wiberg Foundation, Swedish Network for European Studies in Political Science and the Längman Cultural Foundation. She is affiliated to the research group Russia, Ukraine and the Caucasus Regional Research (RUCARR), Malmö University, Sweden.

– ref. I was in Georgia in the late 1980s: I observed how tradition survived harsh Sovietisation and rapid transformation – https://theconversation.com/i-was-in-georgia-in-the-late-1980s-i-observed-how-tradition-survived-harsh-sovietisation-and-rapid-transformation-276911

April 10, 2026

Los astronautas de Artemis II soportarán una temperatura de 3 000 °C durante la reentrada: ¿cómo sobrevivirán?

Source: The Conversation – (in Spanish) – By Chris James, Senior Lecturer, Centre for Hypersonics, School of Mechanical and Mining Engineering, The University of Queensland

Tras completar con éxito su misión a la Luna, la tripulación de Artemis II está a punto de regresar a la Tierra. Los cuatro astronautas han establecido un nuevo récord de distancia recorrida por el ser humano desde la Tierra: 406 771 kilómetros.

Su viaje de regreso culminará con una reentrada a alta velocidad, hipersónica y extremadamente caliente en la atmósfera terrestre antes de que su nave espacial americe en el océano Pacífico frente a la costa de California, aproximadamente a las 8 de la tarde del 10 de abril, hora local (2 de la madrugada del sábado 11 de abril según la hora peninsular de España).

La reentrada será el último reto al que tendrá que enfrentarse la tripulación en su épica misión de diez días. Conlleva muchos peligros, pero su nave espacial está equipada con una serie de tecnologías para garantizar su seguridad.

Una reentrada veloz

La cápsula Orión que transporta a los astronautas de Artemis II viajará a más de 11 km/s (40 000 km/h) cuando alcance la atmósfera terrestre. Esto es 40 veces más rápido de lo que viaja un avión de pasajeros.

Si, en cambio, consideramos la energía cinética, que es la que posee un objeto debido a su movimiento, al reentrar la cápsula Orión acumulará casi 2 000 veces más energía cinética por kilogramo de vehículo que un avión de pasajeros.

Al igual que cualquier nave espacial que regresa a casa, tendrá que reducir la velocidad y disminuir su energía cinética hasta casi cero para que se puedan desplegar los paracaídas y pueda aterrizar de forma segura en la Tierra.

Las naves espaciales reducen dicha energía realizando una reentrada controlada a través de la atmósfera superior de nuestro planeta, donde utilizan la resistencia aerodinámica contra la atmósfera como freno para desacelerar.

A diferencia de un avión, que suele estar diseñado para ser aerodinámico y minimizar las fuerzas de resistencia con el fin de reducir el consumo de combustible, las naves espaciales que reentran hacen lo contrario: están concebidas para ser lo menos aerodinámicas posible, con el fin de maximizar la resistencia y ayudarles a reducir la velocidad.

Esta desaceleración durante la reentrada puede ser extremadamente brusca.

La desaceleración y la aceleración se suelen expresar en fuerzas g –o “g”, para abreviar–. Se trata de la fuerza de desaceleración o aceleración dividida por la aceleración estándar que todos sentimos debido a la gravedad terrestre. Un piloto de Fórmula 1 experimenta más de 5 g al tomar una curva, lo que se acerca a las fuerzas g máximas que un ser humano puede soportar sin desmayarse.

Las pequeñas cápsulas de reentrada no tripuladas, como la OSIRIS-REx de la NASA, que trajo muestras del asteroide Bennu, simplemente se lanzan a la atmósfera y desaceleran rápidamente. Estas entradas se producen muy rápido, en menos de un minuto. Pero las fuerzas g en ese caso pueden ser superiores a 100, lo cual es aceptable para vehículos robóticos, pero no para los humanos.

Los vehículos tripulados, como la cápsula Orión de la NASA, utilizan fuerzas de sustentación para frenar la entrada a tiempo. Esto reduce las fuerzas g a niveles que los seres humanos pueden soportar y hace que la reentrada dure varios minutos.

Una nave espacial volando junto a una luna circular iluminada por detrás por el sol. — Los cuatro astronautas de Artemis II establecieron un nuevo récord de distancia recorrida por el ser humano desde la Tierra, alcanzando una distancia máxima de 406 771 kilómetros.
NASA

Un reingreso muy caliente

La cápsula Orión reentrará en la atmósfera moviéndose a más de 30 veces la velocidad del sonido. Entonces, una onda de choque envolverá la nave espacial, calentando el aire a 10 000 °C o más, aproximadamente el doble de la temperatura de la superficie del Sol.

El calor extremo convierte el aire que atraviesa la onda de choque en un plasma cargado eléctricamente. Esto bloquea temporalmente las señales de radio, por lo que los astronautas no podrán comunicarse durante las fases más duras de su descenso.

Garantizar una reentrada segura

Las naves espaciales sobreviven al entorno extremadamente hostil de la reentrada gracias a un cuidadoso diseño de sus trayectorias para minimizar el calentamiento en la medida de lo posible.

La nave también lleva un sistema de protección térmica. Se trata, en la práctica, de una manta aislante que protege a la nave espacial y a su tripulación o carga del duro flujo hipersónico que se produce en el exterior.

El sistema de protección térmica está diseñado a medida para el vehículo y su misión. Los materiales que pueden soportar más calor se colocan en las superficies donde se prevé que el entorno sea más hostil y están diseñados para degradarse durante la reentrada, pero aguantarán. El resplandor al rojo vivo que experimentarán también irradia calor de vuelta a la atmósfera en vez de que sea absorbido por la nave espacial.

Este diseño preciso es lo que permite a Artemis atravesar el aire a 10 000 °C mientras mantiene una temperatura máxima de la superficie del escudo térmico de solo unos 3 000 °C.

Un rastro de luces brillantes sobre un fondo negro. — Imagen de la nave espacial Hayabusa de la JAXA reentrando en la atmósfera terrestre el 13 de junio de 2010, con el cuerpo de la nave ardiendo detrás de ella.
NASA

La mayoría de las naves espaciales están protegidas por materiales llamados ablativos, que suelen estar fabricados con fibra de carbono y un tipo de pegamento conocido como resina fenólica. Estos escudos térmicos ablativos absorben energía e inyectan un gas relativamente frío en el flujo a lo largo de la superficie del vehículo, lo que ayuda a enfriar todo.

Concretamente, el material del escudo térmico ablativo utilizado en la cápsula Orión se llama AVCOAT y es una versión del material que protegió la cápsula Apolo cuando regresó de la Luna a finales de la década de 1960 y principios de la de 1970.

Aunque la misión Artemis I –un vuelo de prueba no tripulado– fue un gran éxito, la ablación del escudo térmico durante la reentrada fue mucho mayor de lo esperado. Grandes trozos de material se desprendieron en algunos puntos.

La parte superior quemada y ennegrecida de una nave espacial. — El escudo térmico de la nave espacial Orión de la NASA tras la misión Artemis I.
NASA

Tras largas inspecciones y análisis, los ingenieros decidieron seguir adelante con el mismo tipo de escudo térmico en la misión Artemis II. La hipótesis es que Artemis I perdió fragmentos de este recubrimiento debido a una acumulación de presión en el interior del material durante el “salto” de su entrada, fase en la que la nave espacial salió de la atmósfera para enfriarse antes de realizar una segunda entrada en la que aterrizó.

Para Artemis II, los ingenieros han decidido modificar ligeramente la trayectoria, incluyendo un “salto” menos definido.

Es increíble ver lo que la NASA y los astronautas han logrado en esta misión hasta ahora. Pero, como muchos otros, me sentiré aliviado cuando los vea regresar sanos y salvos a la Tierra.

Chris James recibe financiación del Consejo Australiano de Investigación, el Grupo de Ciencia y Tecnología de Defensa de la Commonwealth, la Oficina de Investigación Naval de Estados Unidos y la Oficina de Investigación Científica de la Fuerza Aérea de Estados Unidos.

– ref. Los astronautas de Artemis II soportarán una temperatura de 3 000 °C durante la reentrada: ¿cómo sobrevivirán? – https://theconversation.com/los-astronautas-de-artemis-ii-soportaran-una-temperatura-de-3-000-c-durante-la-reentrada-como-sobreviviran-280376

April 10, 2026

Élection à Djibouti : le président vieillissant s’apprête à prolonger son mandat après avoir modifié la Constitution

Source: The Conversation – in French – By Federico Donelli, Associate Professor of International Relations, University of Trieste

Le président de Djibouti, Ismaïl Omar Guelleh, a fait adopter en octobre 2025 des modifications constitutionnelles supprimant la limite d’âge pour les candidats à l’élection présidentielle. Ces réformes lui permettent de rester éligible et de briguer un nouveau mandat au-delà de 2026. Ces modifications lui permettent de rester au pouvoir au-delà de 2026.

Guelleh est déjà au pouvoir depuis 27 ans et est assuré de remporter l’élection du 10 avril 2026, qui a été boycottée par l’opposition. Guelleh dirige un pays de la Corne de l’Afrique où la mer Rouge rencontre l’océan Indien — l’un des emplacements les plus stratégiques au monde. Federico Donelli, qui a étudié le paysage politique djiboutien, décrypte les dynamiques qui lui ont permis de se maintenir au pouvoir.

Qui est Ismaïl Omar Guelleh et quel est son style de gouvernance ?

Ismaïl Omar Guelleh, plus connu sous le nom d’IOG, est président de Djibouti depuis 1999. Il a succédé au premier président du pays, Hassan Gouled Aptidon, dont il a été le chef de cabinet pendant plus de deux décennies.

Aujourd’hui âgé de 78 ans, Guelleh est l’un des dirigeants les plus anciens d’Afrique de l’Est.

Il appartient au groupe ethnique majoritaire des Issa-Somalis, qui monopolise le pouvoir depuis que le pays a obtenu son indépendance de la France en 1977. La population de Djibouti se compose en grande partie de deux groupes principaux : les Issa-Somalis et les Afars. Cette composition démographique reflète la situation dans l’État régional d’Afar, en Éthiopie voisine. Elle se reflète encore plus fidèlement dans l’État de facto du Somaliland en raison des liens claniques et familiaux.

Par conséquent, la dynamique politique à Djibouti s’entremêle fréquemment avec les développements dans ces États voisins. Cela est particulièrement vrai en matière de sécurité, de mobilité transfrontalière et de réseaux claniques.

En théorie, Djibouti est une république présidentielle dotée d’un système multipartite. Dans la pratique, cependant, le pouvoir politique reste fortement centralisé, laissant peu de place à une véritable concurrence politique.

Le parti au pouvoir, le Rassemblement populaire pour le progrès (RPP), domine le parlement, détenant 45 des 65 sièges. La coalition pro-présidentielle au sens large, l’Union pour la majorité présidentielle (UPM), contrôle 58 sièges au total, consolidant ainsi l’influence de l’exécutif sur la sphère législative.

Les coalitions d’opposition telles que l’Union pour l’alternance démocratique (UAD) et l’Union des mouvements démocratiques (UMD) sont confrontées à des contraintes importantes. Elles ont parfois boycotté les élections. Cinq élections présidentielles et cinq élections législatives ont eu lieu depuis 1999.

Les organisations internationales soulignent fréquemment les restrictions imposées aux médias et à la dissidence publique, la majorité des médias étant contrôlés par l’État.

Guelleh doit également sa longévité à un réseau très soudé de fonctionnaires, de membres de sa famille et d’alliés politiques occupant des postes clés au sein du gouvernement et du monde des affaires. La coalition qui l’entoure n’est pas toujours totalement unifiée. Des rivalités subtiles ont émergé de temps à autre entre certaines personnalités politiques et des membres de son cercle restreint. Mais ces dynamiques ne constituent pas une menace politique.

Qu’est-ce qui explique sa longévité ?

Le mandat de Guelleh peut être attribué à une combinaison de changements institutionnels, de facteurs géopolitiques et de dynamiques au sein de l’élite.

L’un de ces éléments est la réforme constitutionnelle. Au fil des ans, le parlement djiboutien a érodé les principales garanties démocratiques de la Constitution de 1992.

La première mesure a été la suppression de la limitation du nombre de mandats présidentiels en 2010. Ces changements ont permis à Guelleh de se représenter et ont réduit la durée du mandat présidentiel de six à cinq ans.

Le vote parlementaire de novembre 2025 visant à abolir la limite d’âge pour le président s’inscrit dans la même logique. Il a supprimé la dernière restriction formelle à son éligibilité à partir d’avril 2026.

Un deuxième facteur est l’importance stratégique de Djibouti. Situé à l’entrée du détroit de Bab el-Mandeb, une voie maritime vitale reliant la mer Rouge et l’océan Indien, le pays abrite plusieurs bases militaires étrangères. Les États-Unis, la France, la Chine, le Japon et l’Italie y sont représentés.

Pour de nombreux partenaires internationaux, la stabilité du gouvernement djiboutien est considérée comme une source de prévisibilité dans une région instable.

En conséquence, les pressions extérieures en faveur d’une réforme politique ont été limitées, ce qui a, à son tour, renforcé la stabilité du pouvoir en place.

Troisièmement, la cohésion de l’élite au pouvoir joue un rôle central dans la politique intérieure. Un réseau de personnalités influentes, comprenant des membres de la famille du président, des conseillers de longue date et des figures du monde économique, s’est formé autour du leadership de Guelleh. Ce groupe contrôle des institutions étatiques clés ainsi que des secteurs importants de l’économie, ce qui constitue une forte incitation à maintenir la continuité du pouvoir.

L’économie de Djibouti repose principalement sur les services portuaires et logistiques, en particulier son port international qui dessert le commerce régional, ainsi que sur les revenus générés par l’accueil de multiples bases militaires étrangères.

Dans le même temps, l’absence de successeur ouvertement désigné a déclenché une compétition silencieuse au sein de ce cercle. La perspective d’une ère post-Guelleh a, ces dernières années, encouragé diverses personnes à chercher à accroître leur influence. Cela va des membres de la famille aux conseillers de haut rang et aux personnalités politiques.

Les rivalités émergentes ne remettent pas ouvertement en cause l’autorité du président. Elles illustrent néanmoins les dynamiques internes complexes qui sous-tendent l’ordre politique actuel.

Quelles sont ses réalisations et ses promesses ?

Au cours de ses plus de deux décennies au pouvoir, Guelleh a assuré une période de relative stabilité à Djibouti. Alors que la Somalie et l’Éthiopie voisines ont connu une insécurité persistante et des conflits internes, Djibouti est resté relativement épargné.

Le gouvernement cite fréquemment cette stabilité comme l’une des caractéristiques marquantes de son mandat.

Djibouti a également renforcé sa position de plaque tournante stratégique. La présence de nombreuses bases militaires étrangères, ainsi que d’installations portuaires et logistiques, a généré d’importantes recettes pour l’État.

Depuis 2016, les investissements et la gestion chinois ont de plus en plus façonné les principales infrastructures portuaires du pays, intégrant davantage Djibouti dans les réseaux commerciaux mondiaux. Ces facteurs ont renforcé la visibilité du pays dans les accords internationaux en matière de commerce et de sécurité.

En outre, Djibouti a joué un rôle dans la diplomatie régionale. C’est un membre important de l’Autorité intergouvernementale pour le développement (IGAD). Il s’agit de l’organisation régionale chargée de traiter les conflits liés aux ressources, à la concurrence politique et à l’identité. L’engagement le plus récent de Djibouti comprend sa participation aux tentatives de médiation du conflit au Soudan.

Le gouvernement a également mis en avant certaines réformes institutionnelles comme des marqueurs de progrès. L’abolition de la peine de mort en 2010 en est un exemple.

Cependant, les défis structurels restent importants. Djibouti a une population très jeune. Des problèmes tels que le chômage, le coût élevé de la vie et la participation politique limitée persistent.

Que nous apprend le vote sur la limite d’âge sur la politique à Djibouti ?

La décision a été adoptée sans débat public et sans voix contre parmi les 65 législateurs présents. Cela reflète à quel point l’Assemblée nationale s’aligne sur l’exécutif.

Ce vote met également en évidence le rôle central du consensus des élites dans le système politique djiboutien. Des figures clés de la coalition au pouvoir, notamment des représentants des élites Issa et des élites Afar cooptées, ont soutenu la réforme. Pour ces groupes, le maintien de la continuité du pouvoir est souvent considéré comme un moyen de préserver l’accès aux ressources économiques et politiques. Cette option est préférée aux incertitudes liées à un changement de direction.

Le fait de contourner un vote populaire sur la disposition constitutionnelle limite la possibilité d’évaluer les véritables niveaux de soutien ou d’opposition. Cela a pour effet d’exclure en particulier les jeunes citoyens qui n’ont connu qu’un seul président.

Dans l’ensemble, ce vote montre que les dispositions constitutionnelles peuvent être modifiées lorsqu’elles font obstacle à la continuité du pouvoir. Cela renforce un modèle dans lequel les règles formelles s’adaptent aux besoins politiques plutôt que de les contraindre. Cela met également en évidence l’importance de la cohésion des élites pour le maintien de l’ordre politique actuel.

À l’approche de l’élection présidentielle de 2026, le discours dominant du gouvernement reste celui de la continuité, soutenu par ceux qui considèrent la stabilité comme essentielle à la protection des intérêts nationaux et régionaux.

Cependant, les pressions socio-économiques et les inquiétudes sous-jacentes concernant la succession inévitable continuent d’influencer les attentes du public, en particulier parmi les jeunes citoyens.

Cet article a été mis à jour en prévision de l’élection de Djibouti en avril 2026.

Federico Donelli is affiliated with the Italian Institute for International Political Studies (ISPI), the Nordic Africa Institute (NAI), and the Orion Policy Institute (OPI).

– ref. Élection à Djibouti : le président vieillissant s’apprête à prolonger son mandat après avoir modifié la Constitution – https://theconversation.com/election-a-djibouti-le-president-vieillissant-sapprete-a-prolonger-son-mandat-apres-avoir-modifie-la-constitution-280306

April 10, 2026

La dengue est un problème de plus en plus préoccupant : pourquoi est-il si difficile de la combattre avec des vaccins

Source: The Conversation – in French – By Marielena Vogel Saivish, Research Fellow in Virology (Post-Doc position), The University of Texas Medical Branch

La dengue, une maladie transmise par les moustiques, touche chaque année des millions de personnes en Asie, en Afrique et en Amérique latine. Et elle se propage géographiquement, car le réchauffement climatique et l’urbanisation permettent aux populations de moustiques de prospérer dans de nouvelles régions.

À première vue, la dengue semble être une candidate évidente à la vaccination. Elle est causée par un virus. L’infection déclenche une réponse immunitaire. Des vaccins contre des virus similaires existent déjà.

Mais la dengue est complexe. Elle n’est pas causée par un seul virus, mais par quatre virus étroitement apparentés, appelés sérotypes. Lorsqu’une personne est infectée par l’un d’entre eux, le système immunitaire la protège généralement contre ce type spécifique, mais pas contre les trois autres. Dans certains cas, une infection antérieure peut en fait faciliter l’apparition d’une nouvelle infection.

Il n’est donc pas étonnant que la dengue soit l’une des maladies virales transmises par les moustiques les plus courantes au monde. Les scientifiques estiment qu’environ 390 millions d’infections surviennent chaque année, ce qui en fait un problème de santé publique majeur en Afrique.

À l’heure actuelle, un vaccin contre la dengue est autorisé à l’échelle mondiale. Le Dengvaxia ne doit être utilisé que si la personne a déjà été infectée. Un vaccin plus récent, le TAK-003, a été recommandé par l’Organisation mondiale de la santé pour une utilisation chez les enfants âgés de 6 à 16 ans dans les zones à forte transmission de la dengue, quel que soit leur statut d’infection antérieure. Il est administré en deux doses. De plus, des vaccins de nouvelle génération sont en cours de développement, notamment au Brésil.

Notre travail de chercheurs en immunologie virale et en maladies transmises par les moustiques vise à comprendre comment les réponses immunitaires façonnent la protection contre des virus tels que celui de la dengue.

Nos recherches récentes ont passé en revue des décennies d’études sur les vaccins contre la dengue, y compris des essais cliniques et des analyses immunologiques. Les données montrent que les vaccins contre la dengue doivent générer une réponse immunitaire soigneusement équilibrée contre les quatre sérotypes viraux. Si la protection est incomplète ou inégale, cela peut augmenter le risque de forme grave de la maladie chez certaines personnes.

La compréhension de ces mécanismes immunitaires est essentielle pour concevoir des vaccins plus sûrs et plus efficaces.

Dans l’ensemble, l’efficacité des vaccins varie encore en fonction de facteurs tels que les infections antérieures, l’âge et l’intensité de la transmission, ce qui signifie que les stratégies de vaccination doivent être soigneusement adaptées à chaque population.

La dengue en Afrique

Des épidémies de dengue et des preuves de transmission ont été documentées au Kenya, Tanzanie, Soudan, Sénégal et Côte d’Ivoire. Elle pourrait être encore plus répandue sur le continent qu’on ne le pensait auparavant, en partie parce que les systèmes de dépistage et de surveillance sont encore en cours de développement dans de nombreuses régions.

La maladie se propage par la piqûre de moustiques Aedes infectés, en particulier Aedes aegypti. Ces moustiques se reproduisent dans les eaux stagnantes, souvent situées à proximité des zones habitées. Les symptômes de la dengue comprennent une forte fièvre, des maux de tête, des douleurs derrière les yeux, des douleurs musculaires et articulaires, des nausées et des éruptions cutanées. La plupart des personnes se rétablissent en une semaine environ, mais dans certains cas, l’infection peut s’aggraver et entraîner des hémorragies, des lésions organiques ou un choc. La transmission a tendance à augmenter pendant la saison des pluies, lorsque les populations de moustiques se développent.

Au cours des dernières décennies, le nombre de cas a fortement augmenté, l’urbanisation, les voyages et le changement climatique ayant élargi l’habitat des moustiques.

La recherche d’un vaccin

L’infection par un sérotype de la dengue confère généralement une protection à long terme contre ce sérotype spécifique. Le problème survient lorsqu’une personne est ensuite infectée par un sérotype différent.

Au lieu d’offrir une protection, les anticorps issus de la première infection peuvent parfois aider le deuxième virus à pénétrer plus facilement dans les cellules.

Ce processus, connu sous le nom facilitation dépendante des anticorps, a été associé à des formes plus graves de la maladie, notamment la dengue hémorragique et le choc. En termes simples : la mémoire du système immunitaire peut parfois se retourner contre l’organisme. Cette caractéristique biologique rend le développement d’un vaccin particulièrement difficile.

Nos recherches ont révélé plusieurs schémas importants.

Tout d’abord, l’efficacité du vaccin dépend fortement du fait que la personne ait déjà contracté la dengue. Dans certains essais à grande échelle, les vaccins ont offert une bonne protection aux personnes qui avaient déjà été infectées. Mais pour les personnes qui n’avaient jamais été exposées au virus, la protection était plus faible et, dans certains cas, le risque d’hospitalisation augmentait après une infection ultérieure.

Deuxièmement, la qualité des anticorps importe autant que leur quantité. Il ne suffit pas de produire des taux élevés d’anticorps. Ces anticorps doivent être fortement neutralisants, c’est-à-dire capables de bloquer complètement le virus. Des anticorps faiblement neutralisants peuvent ne pas parvenir à stopper l’infection et contribuer à aggraver la maladie.

Troisièmement, l’âge et l’intensité de la transmission influencent les résultats. Dans les zones où la dengue circule largement et où de nombreuses personnes y sont exposées tôt dans leur vie, les schémas d’efficacité du vaccin diffèrent de ceux observés dans les régions où la première exposition survient plus tard.

Pourquoi c’est important

Des pays où l’activité de la dengue était auparavant limitée sont désormais confrontés à des épidémies. Les vaccins restent l’un des outils de santé publique les plus puissants.

Mais une compréhension incomplète peut saper la confiance du public. La confusion autour de la vaccination contre la dengue a, par le passé, contribué à la peur et à la désinformation dans certaines communautés.

Par exemple, l’introduction du vaccin Dengvaxia a suscité la controverse aux Philippines après que des études de suivi ont montré que les résultats du vaccin différaient selon que les personnes avaient déjà été infectées par la dengue ou non. Il est essentiel d’expliquer de tels résultats et leurs causes.

Des données issues de multiples essais cliniques, études épidémiologiques et groupes de recherche en immunologie à travers le monde montrent que les vaccins contre la dengue doivent être évalués non seulement pour leur efficacité globale, mais aussi pour leurs performances par rapport à différents groupes de populations. Il s’agit notamment des personnes ayant déjà été infectées ou non, différents groupes d’âge et des régions présentant des niveaux de transmission variables.

Nos recherches démontrent également que les réponses immunitaires doivent être soigneusement mesurées.
La protection ne consiste pas simplement à générer des anticorps. Il s’agit de générer le bon type d’anticorps.

Ces connaissances orientent déjà de nouvelles stratégies vaccinales. Certains candidats vaccins se concentrent sur l’amélioration d’une immunité équilibrée pour les quatre sérotypes. D’autres visent à affiner la manière dont les réponses immunitaires sont stimulées afin de réduire le risque d’amplification.

Se préparer aux épidémies

Plusieurs enseignements se dégagent pour les pays qui se préparent à des épidémies de dengue.

Premièrement, les stratégies de vaccination doivent être adaptées au contexte épidémiologique. Dans les régions où la plupart des adolescents ou des adultes ont déjà été infectés, certains vaccins peuvent être très bénéfiques. Dans les zones à faible transmission, un dépistage préalable à la vaccination pour déterminer l’exposition antérieure peut s’avérer nécessaire.

Deuxièmement, la surveillance à long terme de la sécurité est essentielle. Les effets du vaccin contre la dengue ne deviendront peut-être pleinement visibles que plusieurs années après son déploiement, une fois que les personnes vaccinées auront été exposées à l’infection naturelle. Les systèmes de surveillance doivent être suffisamment solides pour détecter les tendances à un stade précoce.

Troisièmement, la communication doit être transparente. La confiance du public repose sur des explications claires tant des avantages que des risques. Il n’est pas nécessaire de simplifier une science complexe pour en faire une certitude trompeuse. Elle peut être expliquée honnêtement et clairement.

Enfin, les investissements dans la recherche doivent se poursuivre. La dengue montre que tous les virus ne suivent pas de règles simples.

La leçon à en tirer va au-delà de la dengue. À mesure que les maladies transmises par les moustiques se propagent en raison des changements environnementaux, d’autres virus complexes pourraient poser des défis similaires. Il est de plus en plus important d’apprendre à concevoir des vaccins pour des agents pathogènes biologiquement complexes.

Marielena Vogel Saivish 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. La dengue est un problème de plus en plus préoccupant : pourquoi est-il si difficile de la combattre avec des vaccins – https://theconversation.com/la-dengue-est-un-probleme-de-plus-en-plus-preoccupant-pourquoi-est-il-si-difficile-de-la-combattre-avec-des-vaccins-279916

April 10, 2026

Pope Leo’s visit to Africa: theology scholar outlines 3 realities the Catholic church must face

Source: The Conversation – Africa – By Stan Chu Ilo, Research Professor, World Christianity and African Studies, DePaul University

Pope Leo’s decision to make Africa one of the early destinations of his young papacy signals the continent’s importance in global Catholicism. His April 2026 visit reflects both his personal ties to Africa and the rapid rise of Christianity across the continent.

His 10-day itinerary to Algeria, Angola, Cameroon and Equatorial Guinea is also historically significant. In Algeria, for instance, Pope Leo will walk in the footsteps of Augustine of Hippo (who lived around the year 400), his spiritual father, highlighting the African roots of Christianity.

But when the pope announced his Africa trip in February 2026, few could have anticipated how rapidly the global security landscape would deteriorate. There is a real risk that ongoing global crises, such as the conflict in Iran, will dominate attention, overshadowing both the significance of Pope Leo’s visit and the persistent, often overlooked, conflicts across Africa.

The last papal visit to Africa – by his predecessor, Pope Francis, in 2023 to the Democratic Republic of Congo and South Sudan – was similarly intended to draw attention to Africa’s enduring wars. Vast refugee settlements across the continent stand as stark reminders of lives suspended in uncertainty and suffering.

I am an African theologian and my work examines how contemporary Catholicism is changing. My research goes beyond tracking the demographics of Christian expansion. It asks how Christian communities, rooted in diverse cultures, are transforming societies and cultures in line with the Gospel.

By choosing to visit Africa now, Pope Leo is making a clear statement: Africa matters. The Catholic church on the continent can seize this moment to build more equal, non-patronising partnerships with churches in the global north, where membership is declining.

Christianity’s African roots

Christianity is not a recent import to Africa brought by European missionaries. The continent has long provided deep cultural, spiritual and theological roots for Christianity. This includes Joseph and Mary’s flight into Egypt when the life of Jesus was threatened by Herod after his birth, and the catechetical school of Alexandria, the world’s oldest centre of Christian higher learning.

Pope Leo’s visit offers a powerful historical reminder of the continent’s foundational role in shaping the church, particularly in its first five centuries.

Additionally, Africa is home to the fastest-growing Catholic population, now estimated at 280 million Catholics, or 19.8% of the world’s Catholic population. In 2025 alone, the African Catholic church had 8.3 million new members.

Africa contributes significantly to the church’s global human capital. Nigeria, South Africa and the Democratic Republic of Congo are among the top 10 “sending nations” in the missionary exchange from the global south to the global north.

Pope Paul VI was the first modern pope to visit Africa, in 1969. He said the time had come for Africa to have “an African Christianity”.

Many African Catholics see this speech as an invitation to Africans to take responsibility for making Christianity truly Catholic and truly African.

Pope John Paul II later, in 1995, affirmed that the “hour of Africa” had come. Pope Benedict XVI, during his 2009 visit to Africa, described the continent as a “spiritual lung” for a world in crisis.

These expressions signal a shared conviction: the church in Africa has come of age and stands as a major spiritual force in the contemporary expansion of global Christianity.

Some challenges persist

Pope Leo is no stranger to the continent. He visited several African countries during his two terms as the global head of the Order of St Augustine, headquartered in Rome.

However, he will encounter a persistent and troubling paradox that marks both the church and wider society. The rapid growth of Christianity has not consistently translated into better lives for people. If the church is to remain relevant, it must more convincingly embody the Gospel’s transformative power within the lived realities of African societies.

It needs to address the fluid religious imagination of many African Christians who easily migrate from mainline Christian groups like Catholicism to Pentecostalism and African traditional religion. This means the Catholic church needs a moment of self-introspection to ask if it is really meeting the people at their points of need. Is it a church that bears the narratives and wounds of the people?

Without addressing the deeper crisis of faith and the battle for survival in Africa by so many believers walking in poverty, the church risks becoming a provider of charitable services. It could instead be a force for deeper social transformation, religious and moral conversion, and spiritual renewal.

Pope Leo’s visit also unfolds within politically sensitive contexts.

In Cameroon, the long-running conflict in Anglophone regions and President Paul Biya’s long rule have raised concerns. A papal visit could be interpreted as legitimising power structures that many see as repressive. Biya’s decades in power have been associated with electoral manipulation, repression of dissent and state capture.

Similar tensions exist in Equatorial Guinea. President Teodoro Obiang has been in power for 47 years. His rule has been marked by the suppression of the opposition in an oil-rich yet deeply unequal nation.

The image of two long-serving rulers standing with Pope Leo will be striking. It will raise questions. But it will also create an opportunity for the pope to speak some hard truths to leaders who are destroying Africa.

By contrast, Angola offers a more hopeful narrative of post-conflict recovery. It demonstrates how collaboration between the church, state and civil society can yield gradual but meaningful progress.

Africa and the future of a listening church

For all that was said about Pope Francis’ love for Africa, it remains striking that, by his death in April 2025, no African cardinal headed a dicastery (a ministry-level department of the central administration of the Catholic church in Rome).

Africans accounted for barely 12% of the College of Cardinals. Its members are the closest advisors of the pope and choose new popes.

Pope Leo has already begun to address this imbalance in key commissions and administrative structures by appointing Africans to positions of real influence.

One of the most notable traits attributed to him is his capacity to listen. In my view, this listening must confront three interrelated realities if the church in Africa is to become a credible agent of transformation.

Dependency: Parishes and pastoral programmes in Africa still depend on financial support from Europe and North America. This is a major obstacle to the emergence of a mature and self-sustaining African Christianity. The church risks reproducing asymmetrical power dynamics that weaken human agency and pastoral creativity.

Decolonisation: Inherited church structures and theological frameworks should be interrogated. Without this, the church won’t be rooted in the lived experiences and realities of African peoples.

Leadership: The crisis of leadership in Africa is mirrored within the church. What is needed is a transformational, humble and servant leadership grounded in accountability, transparency and shared responsibility. This means greater inclusion of the voices and assets of the laity, especially of women.

Pope Leo’s visit is a key moment for the Catholic Church in Africa. Will it remain a recipient of global Catholicism or help shape its future?

Stan Chu Ilo 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. Pope Leo’s visit to Africa: theology scholar outlines 3 realities the Catholic church must face – https://theconversation.com/pope-leos-visit-to-africa-theology-scholar-outlines-3-realities-the-catholic-church-must-face-280069

April 10, 2026

Hands off my hat! The hidden power of headwear and ‘hatiquette’ in early modern England – new study

Source: The Conversation – UK – By Bernard Capp, Emeritus Professor of History, University of Warwick

Roundhead and cavalier soldiers, wearing partisan hats, face each other and urge their dogs to attack each other (1643). State Library Victoria, Melbourne , CC BY-SA

Around 8pm on a cold February evening in 1733, a gentleman named Francis Peters was returning to his home near Knightsbridge, London, in a hackney cab, when someone knocked on the wooden shutters of the door. An armed horseman thrust a pistol inside, demanded Peters’s money and valuables and snatched a ring from his finger. Peters handed them over without fuss. But when the thief also snatched his hat and wig, he protested vigorously, though in vain – the robber rode away with his booty.

The puzzle, to the modern reader, is that the hat was worth only five shillings – far less than the watch (worth £4), the ring and the cash he had already handed over. So why make such a fuss?

Woodcutting showing three Levellers wearing hats — Levellers wearing their hats.
Bodleian Libraries, University of Oxford

The robber was later arrested and Peters made a point of going to see him in Newgate Prison as he awaited trial. He told him it had been bad manners to take his hat. The Old Bailey trial records tell us that the highwayman apologised.

Historically, hats had a significance that went far beyond fashion and keeping the head warm. For any respectable man in Tudor, Stuart and Hanoverian England, to go hatless was almost unthinkable, while for people lower down the social scale, it suggested total destitution. Suspects awaiting trial were often desperate to obtain a hat before appearing in court, to present at least a shred of respectability. But what made it so unthinkable for respectable men to appear hat-less?

As my new research explains, the power of social convention is certainly one part of the answer. Another is contemporary concerns over health and the belief that it was important to keep the head warm at all times. Wearing a nightcap, after all, was common practice. Peters raised his own health concerns when he pleaded with the highwayman. A man who wore a wig as well as a hat would generally have had his head shaved, so the theft left him bare-headed and vulnerable on a cold winter night.

Madness and status

There was another factor, too – the association of a bare head with madness, which was familiar through images of the shaven inmates of Bedlam. The strength of that association can be seen through another strange story – that of Thomas Ellwood, the teenage son of an Oxfordshire gentleman.

In 1659, by chance, Ellwood and his father had come across the Quakers, a new movement at the time. Thomas was intrigued but his father was appalled, and forbade him to attend any Quaker meetings. Thomas sneaked away regardless, even after his father had beaten him and banished him from the dinner table.

Eventually his father found a bizarre tactic that did work: he confiscated all his son’s hats. Many years later, Ellwood explained in his autobiography that the move had rendered him effectively a prisoner for many months, “unless I would have run about the country bare-headed, like a mad-man: which I did not see it my place to do”. He would have appeared deranged, and he recognised the shame that such behaviour would bring to a gentleman’s family.

Painting of men wearing top hats — Hats were an indicator of status in early modern England. The only man not wearing a hat in this illustration is a servant in the gaming house and so a social inferior.
Yale Center for British Art, Paul Mellon Collection, CC BY

As that concern suggests, the hat also had a far wider significance in this period as a marker of status and in associated gestures of deference. Unlike today, almost everyone wore a hat or, in the case of labourers and poor artisans, a flat cap. And convention required men and boys to doff the hat or cap in the presence of someone of higher status – a parent, master, employer, gentleman, magistrate, peer, or monarch.

Though there was no law to underpin “hat-honour”, the convention was firmly enforced. Many people who had grown up with this convention may have accepted it as part of the natural order of things, but having to “bow and scrape” to a harsh landlord, for example, was deeply resented by others. And in times of political upheaval, such as the civil wars of the 1640s, hat-honour could take on an ideological significance.

John Lilburne was a leader of the radical Leveller movement that was pressing for social reforms and a more accountable form of government. He refused to doff his hat when he was summoned to appear before the House of Lords for publishing illicit tracts, and announced his defiance in a pamphlet.

Many other radical leaders made similar gestures of defiance. Most notorious were the early Quakers, who refused on principle to doff their hats to anyone, explaining it as a gesture against the sin of pride and vanity.

Changing fashions

Refusing hat honour was an overt gesture of defiance associated with radicals, whether political, religious. But after the civil war of the 1640s ended with parliament’s victory over Charles I, the political order was turned upside down, and such gestures might now appeal to the defeated royalists.

At the trial of the king in January 1649, Charles himself refused to remove his hat when brought into court. As sovereign, he refused to recognise any superior on earth, or to accept that any court had the right to try him.

The importance of hat-honour gradually faded in later centuries, as manners became more informal and crowded cities made it ever less practicable. And finally, in the 1960s, the practice of men wearing hats abruptly ceased, for reasons that remain largely unexplained. The “swinging sixties” celebrated youth, informality and the rejection of old, hidebound conventions – and that cultural shift may provide at least a part of the answer.

Bernard Capp 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. Hands off my hat! The hidden power of headwear and ‘hatiquette’ in early modern England – new study – https://theconversation.com/hands-off-my-hat-the-hidden-power-of-headwear-and-hatiquette-in-early-modern-england-new-study-280175