Scholars widely agree that astronomy is a gateway science – that it inspires a core human interest in science among people of all ages, from senior citizens to schoolchildren. Helping young people tap into their excitement about the night sky helps them build confidence and opens career pathways they may not have considered before.
Yet today the night sky is often hidden from view. Almost all Americans live under light-polluted skies, and only 1 in 5 people in North America can see the Milky Way. When people live in areas where the night sky is clearer, they tend to express a greater wonder about the universe. Altogether, this means communities with less light pollution have great potential to educate the next generation of scientists.
Rural communities have some of the darkest skies in the country, making them perfect for stargazing. Yet while students in rural areas are in the optimal physical environment to be inspired by the night sky, they are the most in need of science, technology, engineering and mathematics, or STEM, education resources to support their interests and build the confidence they need to pursue careers in science.
Stargazing, finding constellations and watching meteor showers as a kid inspired my own sense of awe around the vastness of space and possibilities in our universe. Now, I’m the executive director of the Smithsonian’s Scientists Taking Astronomy to Rural Schools, or STARS, a new program led by the Smithsonian Astrophysical Observatory, part of the Center for Astrophysics | Harvard & Smithsonian, that delivers telescopes and associated lesson plans to rural schools across the United States, free of charge. I’m working to share my excitement and wonder with students in rural areas.
A solar eclipse, as viewed through a telescope. STARS
Why hands-on STEM learning matters
Students need direct exposure to STEM careers and hands-on experiences that help them learn the skills they will need to pursue these careers on their own. Hands-on activities ground new knowledge in ways that lectures and reading often cannot. Experiential opportunities connect what may be distant or abstract concepts to clear, tangible, real-world skills. This experiential learning improves students’ understanding of astronomy content and increases their motivation to learn.
Telescopes are important tools for astronomy that scientists use all the time. When students use telescopes as part of their learning, they are experiencing real techniques that scientists use. Using a telescope brings the viewer closer to fantastic celestial objects – allowing them to see galaxies, nebulas, planets, the Moon and the Sun, with solar filter protection, more closely or in greater detail.
Telescopes help students view astronomical objects, like the Moon, up close. STARS
There is nothing quite like seeing the soaring peaks and shadowed valleys of the Moon, or the distinct ring structure of Saturn, or endless other astronomical objects, through a telescope lens. This inspiration can motivate students to use their curiosity to explore the universe and see STEM careers as potential pathways.
Rural STEM education
The National Rural Education Association’s Why Rural Matters 2023 report estimates that there are 9.5 million students attending school in rural areas in the U.S., across more than 32,000 schools. This is more students than the student population of the 100 largest U.S. school districts combined.
While rural communities around the country all look different, they can face similar challenges: limited access to broadband internet, reduced state funding support and restricted geographical access to field trip opportunities, such as museums. Why Rural Matters found, on average, that 13.4% of rural households have a limited internet connection, and for some states this increases to 20%.
Each state distributes their education funding differently. The percentage allocated to rural schools varies from state to state, ranging from 5% to 50% of the total funding, which results in a wide range of money spent per student. Nonrural districts spend an average of US$500 more per student than rural districts. Looking state by state, however, this disparity climbs into the thousands of dollars.
Educators may also consider STEM topics daunting. Many teachers do not feel adequately prepared or confident to introduce these topics to students. In other situations, there simply aren’t enough teachers to cover these topics. Shortages of STEM-focused teachers occur at some of the highest rates in rural districts, reducing rural students’ access to these subjects.
These reasons are why, through the STARS program, we give teachers access to a national community of practice that supports peer sharing and participation, alongside the telescope and science-aligned lesson plans. The lesson plans will be available online for anyone to use later this spring, whether or not they are part of the program.
Rural areas farther from cities tend to have darker skies, better for stargazing. Ryan Hutton/Unsplash
Opportunities to observe the sky with telescopes lead to an improvement in learning outcomes and STEM identity, and rural schools are uniquely situated to introduce students to the night sky. With a little extra support, through community events and educational programs, these schools have the opportunity to inspire the next generation of scientists and engineers.
Emma Marcucci works for the Smithsonian Astrophysical Observatory, as Executive Director of the Smithsonian STARS program, which is supported through private gifts and donations.
Small businesses are planning to hire fewer recent college graduates than they did in 2025, making it likely harder for this cohort to find entry-level jobs.
In our recent national survey, we found that small businesses are 30% more likely than larger employers to say they are not hiring recent college graduates in 2026. About 1 in 5 small-business employers said they do not plan to hire college graduates or expect to hire fewer than they did last year.
This would be the largest anticipated decrease in small businesses hiring new graduates in more than a decade.
This slowdown is happening nationwide and is affecting early-career hiring for people graduating from both college and graduate programs – and is more pronounced for people with graduate degrees.
Nearly 40% of small businesses also said they do not plan to hire, or are cutting back on hiring, recent grads who don’t have a master’s of business administration. Almost 60% said the same for people with other professional degrees.
National data shows the same trend. Only 56% of small businesses are hiring or trying to hire anyone at all, according to October 2025 findings by the National Federation of Independent Business, an advocacy organization representing small and independent businesses.
Job openings at small employers are at their lowest since 2020, when hiring dropped sharply during the early months of the COVID-19 pandemic.
Some small businesses may change their hiring plans later in the spring, but our survey reveals that they are approaching hiring cautiously. This gives new graduates or students getting their diplomas in a few months information on what they can expect in the job market for summer and fall 2026.
About two-thirds of them were small businesses, which reflects their distribution and proportion nationally.
Small businesses employ nearly half of private-sector workers. They also offer many of the first professional jobs that new graduates get to start their careers.
Many small employers in our survey said they want to hire early-career workers. But small-business owners and hiring managers often find that training new graduates takes more time and support than they can give, especially in fields like manufacturing and health care.
That’s why many small employers prefer to hire interns they know or cooperative education students who had previously worked for them while they were enrolled as students.
Larger employers are also being more careful about hiring, but they usually face fewer challenges. They often have structured onboarding, dedicated supervisors and formal training, so they can better support new employees. This is one reason why small businesses have seen a bigger slowdown in hiring than larger employers.
Then there are small businesses in cities that are open to hiring recent graduates but are struggling to find workers. In cities, housing costs are often rising faster than starting salaries, so graduates have to live farther from their jobs.
In the suburbs and rural areas, long or unreliable commutes make things worse. Since small businesses usually hire locally and cannot pay higher wages, these challenges make it harder for graduates to accept and keep entry-level jobs.
Job prospects for recent college graduates depend on the industry. The 2026 survey shows that employers in health care, construction and finance plan to hire more graduates than other fields. In contrast, manufacturing and arts and entertainment expect to hire fewer new graduates.
Most new jobs are in health care and construction, but these fields usually do not hire many recent college graduates. Health care growth is focused on experienced clinical and support roles, while construction jobs are mostly in skilled trades that require prior training or apprenticeships instead of a four-year degree.
So, even in growing industries, there are still limited opportunities for people just starting their careers.
Even though small businesses are hiring less, there are still opportunities for recent graduates. It’s important to be intentional when preparing for the job market. Getting practical experience matters more than ever. Internships, co-ops, project work and short-term jobs help students show they are ready before getting a full-time position.
Employers often say that understanding how the workplace operates is just as important as having technical skills for people starting their careers.
We often remind students in our classes at LeBow College of Business that communication and professional skills matter more than they expect. Writing clear emails, being on time, asking thoughtful questions and responding well to feedback can make candidates stand out. Small employers value these skills because they need every team member to contribute right away.
Students should also prepare for in-person work. Almost 60% of small employers in our survey want full-time hires to work on-site five days a week. In smaller companies, graduates who can take on different tasks and adjust quickly are more likely to set themselves apart from other candidates.
Finally, local networking is still important. Most small employers hire mainly within their region, so building relationships and staying active in the community are key for early-career opportunities.
The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.
I’m an emergency medicine and critical care physician at the University of Colorado. In my 18 years of practicing clinical medicine, this year is one of the worst I have seen. Our emergency department hit a record number of single-day total visits over the holidays, and visit volumes have stayed high. Flu is likely contributing to this trend.
While there is always a season where respiratory viruses hit hard, this year influenza is making patients miserable and wreaking havoc on both the state and national health care system.
How does this year’s ‘super flu’ differ from other flu seasons?
This season is especially rough because of the volume of people seeking emergency care. This flu came on fast and seems to be very contagious, and its symptoms are more severe than other recent years’ flu strains.
Flu tends to cause fever, body aches and maybe a cough. But this so-called super flu has also caused vomiting and diarrhea, which has made people feel much worse than isolated respiratory symptoms alone. When people are feeling worse, they seek emergency care, which is part of why our emergency department is seeing so many people.
In past flu seasons, which typically run from October through February, emergency rooms were full because they were facing multiple outbreaks, such as the 2022 “tripledemic” of COVID-19, flu and RSV.
But this 2025-26 flu season, we’re seeing high emergency department visits specifically from the flu. The first group of patients we’re seeing are healthy people who are feeling worse with this flu, which comes with nausea, vomiting and diarrhea, and come to the emergency department looking for symptomatic relief.
The second group are those with severe manifestations of the flu or who have underlying comorbidities such as asthma or heart disease that can be exacerbated by influenza. This is a population that may require oxygen, or they’re a transplant patient and they’re requiring hospitalization.
This double whammy of people feeling really miserable from their symptoms plus people with comorbidities experiencing complications is when you really see a strain on the health care system.
The CDC ranks Colorado’s flu activity among the highest in the U.S., along with Louisiana, New Jersey, New York and South Carolina.
Kids generally seem to be having milder flu cases than adults, which is typical for some of these viruses. But there have been 17 pediatric deaths associated with influenza across the U.S., with eight in the week ending January 3. That number of deaths in children is not typical at this point in the season.
Young people in their 20s are feeling pretty bad from this year’s flu, but we’re not seeing a lot of complications or hospitalizations in this group across the U.S. and in emergency departments in Colorado.
We’re seeing a lot of people who have underlying conditions, such as asthma, as well as diabetes, obesity, heart disease and those who are immune-compromised. They get the flu, and then it leads to kind of a cascade, or a worsening of their underlying medical problems. This is different from what we saw with COVID-19, where healthy people got very, very sick from COVID-19 itself.
The older you get, the more likely you are to experience complications, such as needing oxygen, which typically requires hospitalization.
Are you still encouraging people to get the flu shot if they haven’t yet?
Yes, you should still consider getting your flu shot, especially if you have medical problems.
Getting the flu shot reduces the risk of severe illness and hospitalization, especially for people who are older or have other medical conditions. Genaro Molina/Getty Images
When should you consider going to an emergency room?
Anytime breathing becomes difficult, or you experience severe chest pain or headaches that are abnormal, that’s something that we want you to seek medical care for right away. And of course, if somebody’s worried about a symptom, we’re here 365 days a year, and we’re happy to help.
If you are feeling bad – such as a mild headache, body aches, fever, sometimes some cough and congestion, and as I mentioned with this flu, potentially vomiting and diarrhea – that is very normal.
If it’s flu, COVID-19 or RSV in a healthy, mildly symptomatic patient, it doesn’t really matter what they have, because there’s not a specific treatment. There’s not anything that we can do that’s going to make them better, other than “tincture of time,” meaning lots of rest.
If you have underlying medical problems, such as diabetes, lung problems or are immune-compromised, and you are experiencing severe symptoms, you should at the very least see your primary care doctor if not the emergency department.
Is it important to get tested for the sake of knowing what you have?
A lot of patients want to know what virus they have, but if you’re young and healthy, there’s not really a need for testing other than surveillance.
Colorado’s infectious disease trackers say wastewater surveillance is the No. 1 way to figure out what infectious diseases are in the community. We can’t get a comprehensive sample through hospitals and clinics, because there are so many people who are home, don’t get tested and do not seek health care.
In Colorado and other states, wastewater is tested for infectious pathogens, including influenza, COVID-19 and RSV. This testing indicates the prevalence of a virus in a given community. Portland Press Herald/Getty Images
In addition, it’s important for the overall health care system that laboratory testing be used judiciously. Testing does help us understand what’s in the community. But from a hospital and emergency department lens, the more tests we send to the lab that have to be run, the more testing services for other illnesses get backed up. It also adds a burden to nursing and other clinical staff, as well as costs for the patient and hospital.
But if a patient is sick with manageable symptoms from a virus, it’s the same standard advice: Stay at home, wash your hands and consider a mask if you have to go out in public.
Jean Hoffman does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
In developing countries, indoor air pollution is framed as a development problem, linked to people cooking and heating with wood, charcoal or other solid fuels, often in homes with limited ventilation.
We have found that air pollution, including exposure inside homes, contributes substantially to premature death worldwide – that is, deaths occurring earlier than expected due to air pollution-related increases in disease risk. Exposure levels and sources vary widely, but indoor air pollution consistently adds to national mortality risk across income levels.
When indoor air pollutants enter the lungs, they can trigger inflammation and place long-term strain on the heart and respiratory system. The same biological processes occur when pollution comes from a wood stove in a rural village or from a poorly ventilated cooker in a modern flat.
Our study does not measure household-level exposure or behaviour. Instead, taking a wider view, we studied country-level patterns and examined how access to clean cooking fuels, electricity, healthcare and broader socioeconomic conditions relate to air pollution mortality risk.
Our results show a clear and consistent pattern. Countries such as the UK with greater access to clean household energy and stronger health systems experience much lower mortality risk linked to air pollution. Countries such as Benin, Cameroon, Guinea, Sierra Leone and Togo, where energy deprivation remains widespread, face far higher risks.
Most existing research on indoor air pollution focuses on rural households and communities. Such work is essential, but it misses the bigger structural picture. Our research reveals the global picture and shows that the same broad drivers influence risk across the world.
At a macro level, access to clean fuels and reliable electricity lowers air pollution mortality risk. Higher healthcare spending also decreases this risk. Larger rural populations and limited household energy access increases such risk.
These patterns help explain why air pollution deaths remain concentrated in emerging and developing economies, while advanced economies experience far fewer deaths, even though air pollution has not disappeared. They also show that indoor and outdoor air pollution cannot be treated as separate problems, because both reflect how energy is produced, used and regulated.
In the UK, people spend most of their time indoors, especially during winter. Heating, cooking and reduced ventilation can raise indoor pollution levels, particularly in poorly ventilated homes. Recent debates about wood-burning stoves reflect growing concern about these risks.
Our research does not assess indoor air quality in UK homes directly. What it offers instead is context. It places the UK debate within a wider pattern where household energy systems shape health outcomes.
The situation in the UK looks less like a narrow lifestyle issue and more like part of a broader global environmental health challenge. This links indoor air quality to energy policy, housing standards and long-term public health costs, not just personal choice.
On one hand, reducing indoor air pollution does not require drastic change in the UK. Simple steps such as using extractor fans when cooking, ventilating homes regularly and ensuring heating appliances are properly maintained can lower exposure. On the other hand, reducing indoor air pollution in developing countries requires access to clean cooking fuels and technology, rural electrification and greater healthcare expenditure.
At a wider level, our findings underline the importance of clean household energy and strong health systems in reducing deaths linked to air pollution. These factors contribute to risk levels across countries, even when the sources of pollution differ.
Indoor air pollution is often treated as either a development issue or a domestic heating issue. Our research suggests it makes more sense to see it as one shared global and national health challenge, with common health effects and structural roots. This connects the indoor air pollution issue more directly to global public health – and the case for action becomes much clearer.
Don’t have time to read about climate change as much as you’d like?
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.
Source: The Conversation – UK – By Simon Thorne, Senior Lecturer in Computing and Information Systems, Cardiff Metropolitan University
The global outcry over the sexualisation and nudification of photographs – including of children – by Grok, the chatbot developed by Elon Musk’s artificial intelligence company xAI, has led to urgent discussions about how such technology should be more strictly regulated.
But to what extent can technology also be used to prevent this explosion in the generation and sharing of deepfake content of real people, without their knowledge or consent?
But while outright national bans can limit casual use of the chatbot, such bans are easily bypassed using virtual private networks (VPNs) or alternative routing services. These mask the user’s real location and make it appear they originate from a location that allows access to the service.
As a result, country-level bans tend to reduce visibility rather than eliminate access. Their primary impact is symbolic and regulatory, placing pressure on companies such as xAI rather than preventing determined misuse. And content generated elsewhere can still circulate freely across borders via encrypted social media platforms and on the dark web.
In response to the controversy, X moved Grok’s image-generation features behind a paywall, making them only available to subscribers. X subsequently posted that it takes “action against illegal content on X, including child sexual abuse material, by removing it, permanently suspending accounts, and working with local governments and law enforcement as necessary”. Grok itself apologised for “the incident”, describing it as a “serious lapse”.
How the technology works
While not all chatbots have image generation capabilities, most of the mainstream providers including OpenAI, xAI, Meta and Google provide this service.
Modern AI image generators are typically built using diffusion models, which are trained by taking real images and gradually adding random visual distortion, known as noise, until the original image is no longer recognisable. The model then learns how to reverse this process, step by step, reconstructing an image by removing noise.
Over time, it will learn statistical patterns representing faces, bodies, clothing, lighting and other visual features. These patterns are organised within the model so that visually similar concepts sit close together. Because clothed and unclothed human bodies share very similar shapes and structures, the changes required to move between them can be relatively small.
So, when an existing image is used as the starting point and identity-preserving features are retained, transforming a clothed photograph into an unclothed one becomes technically straightforward. Of course, the AI model itself has no understanding of identity, consent or harm. It simply produces images that resemble what it has learned, in response to user requests.
However, after the core model has been trained, companies can apply “retrospective alignment” – rules, filters and policies that are layered on top of the trained system to block certain outputs and align its behaviour with the company’s ethical, legal and commercial principles.
But retrospective alignment does not remove capability; it simply limits what the AI image generator is allowed to output. Those limits are primarily a design and policy choice made by the company operating the chatbot, although these may also be shaped by legal or regulatory requirements imposed by governments – for example, requiring companies to disable or restrict certain features such as identity-preserving image generation.
Large, centrally hosted social media platforms could also play an important role here. All have the power to restrict the sharing of sexual imagery involving real people, and to require explicit consent mechanisms from those featured in images. But to date, the big tech companies have tended to drag their feet when it comes to labour-intensive moderation of their users’ content.
‘Jailbreaking’
Research by Nana Nwachukwu, a PhD candidate at Trinity College Dublin’s Centre for AI-Driven Digital Content Technology, highlighted the frequency of requests for sexualised images on Grok. Other research has estimated that before the service went behind a paywall, up to 6,700 undressed images were being produced every hour.
This has prompted regulatory scrutiny in Europe and beyond. French officials described some outputs as manifestly illegal and referred them to prosecutors. The UK’s communications watchdog, Ofcom, has launched an investigation into X and xAI over the issue.
But this problem is not limited to one platform. In early 2024, non-consensual AI-generated sexual images of Taylor Swift, produced using publicly available tools, spread widely on X before being removed because of a combination of legal risk, platform policy enforcement and reputational pressure.
Fake explicit Taylor Swift images raise new concerns about AI. Video: CBS News, January 2024.
Some platforms explicitly market minimal or no content restrictions as a feature rather than a risk. It is simple enough to find websites promoting “unrestricted” image generation and privacy focused use, relying largely on open-source models and offering far fewer moderation controls than mainstream providers. Furthermore, there is an even larger number of self-hosted image and video generation tools where safeguards can be removed entirely.
While precise figures are unavailable, independent estimates suggest tens of millions of AI generated images are created daily across platforms, with video generation rapidly accelerating.
Another potential issue is that some AI chatbots, including Meta’s Llama and Google’s Gemma, can be downloaded onto computers (even those with relatively light processing power), after which these models are completely free of oversight or moderation when run offline.
Even tightly controlled systems can be bypassed through “jailbreaking” – a way of constructing prompts to fool the generative AI system into breaking its own ethics filters.
Jailbreaking exploits the fact that retrospective alignment systems depend on contextual judgment, rather than absolute rules. Rather than directly asking for prohibited content, users reframe their prompts so the same underlying action appears to fall within an allowed category such as fiction, education, journalism or hypothetical analysis.
An early example was known as the “grandma hack”, because it involved a recently deceased grandmother recounting experiences from her technical profession in chemical engineering, leading the model to generate step-by-step descriptions of prohibited activities.
Speed and scale
The internet already contains an enormous quantity of illegal and non-consensual sexual imagery, far beyond the capacity of authorities to remove. What generative AI systems change is the speed and scale at which new material can be produced. Law enforcement agencies have warned that this could lead to a dramatic increase in volume, overwhelming moderation and investigative resources.
Laws that may apply in one country can be ambiguous or unenforceable when services are hosted elsewhere. This mirrors longstanding challenges in policing child sexual abuse material and other illegal pornography, where content is frequently hosted offshore and rapidly redistributed. Once images spread, attribution and removal are slow and often ineffective.
By making countless millions more people aware of the possibility of sexualising and nudifiying images, high-profile AI chatbots make it possible for large numbers of users to generate illegal and abusive sexual imagery through simple plain English prompts. Estimates suggest Grok alone currently has anywhere from 35 million to 64 million monthly active users.
If companies can build systems capable of generating such imagery, they can also stop it being generated. However, the technology exists and there is a demand for it – so the reality is, this capability can never now be eliminated.
Simon Thorne 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.
Psychologists and nutritionists both agree that short-term, restrictive diets aren’t great for long-term weight loss success.metamorworks/ Shutterstock
Those hoping to lose weight this year might be tempted to try to a diet challenge in the hopes of kick-starting their weight loss. But while we might think these kinds of short-term, restrictive diets will help give our waistlines a nudge, psychology and physiology shows us why this strategy can be so hard to stick to – and why it probably won’t result in long-term weight loss.
Research estimates that as few as 20% of people who lose weight through dieting manage to keep the weight off long-term.
For decades, psychologists have been trying to understand why it is that diets so often fail.
One potential reason for this is that diets often involve strict food rules – such as avoiding the foods you enjoy.
The problem with this strategy is that the foods people tend to crave most – such as chocolate, ice cream and crisps – activate the brain’s reward system. This creates positive feelings.
When we cut these foods out of our diet, we lose the pleasure they bring. This can then trigger food cravings – a complex psychological process where we experience an intense desire to eat a particular food, even when we’re not hungry.
Food cravings are often dependent on mood and may be particularly bad when we feel stressed. They can also be especially intense in the afternoon and evening when we feel more tired and have less willpower to resist these cravings.
Food cravings can drive overeating, especially when trying to diet. One review even showed that when people deliberately excluded certain foods from their diet, they experienced an increase in cravings for the foods they were avoiding.
Although the review’s authors conclude that this response can be unlearned, it explains why even short-term restrictive diets tend not to work. Crash diets can trigger stronger food cravings, which can make it harder to stick to your goals – and may even lead to weight gain instead.
Nutritionists also agree that short-term restrictive diets aren’t great for long-term weight loss success.
Our appetite (how hungry we feel) and satiety (how long we feel full) are controlled by complex physiological signalling pathways that play a significant role in weight loss.
When we follow very low-calorie diets, our bodies react by increasing appetite, reducing satiety and even reducing energy expenditure (how many calories we burn).
The body also compensates for drastic calorie reductions by sending stronger hunger signals to the brain. This can drive overeating.
These physiological responses mean diets that are too restrictive can make weight loss harder – and may even lead to weight regain.
From an evolutionary perspective, these responses helped our ancestors to survive food scarcity – but today, it explains why severe calorie restriction so often leads to weight regain. In fact, research shows that people tend to regain about 50%–70% of the weight they lose after dieting.
Another possible explanation for this phenomenon is that you’re not just losing fat when the scale drops – you lose muscle too. This matters because muscle is a key contributor to resting energy expenditure, which is part of your metabolism. Research has also shown that a loss of muscle mass is associated with weight regain.
Since rapid weight loss diets create a large energy deficit and may contain lower amounts of protein, this increases the risk of losing muscle mass. It also increases your chances of regaining weight you may have lost while on the diet.
The best strategies for weight loss
If you’re aiming to make a substantial weight loss attempt, an “all-or-nothing” crash diet may not be your best option. A slower, more balanced approach is far more likely to protect your muscles and support longer-lasting results.
Think nutrient quality, not calories
When it comes to eating well, the key is not to “diet”. As we’ve shown, restricting calories often backfires as our bodies and brains compensate by increasing food cravings and hunger signals. So instead of focusing on what to cut out, think about what you can add to meals to make them healthier.
The types of food we eat influences our appetite and satiety signals – not just the number of calories we consume. For example, protein provides feeling of fullness, and high-fibre carbohydrates keep us more satisfied than highly processed refined ones.
So, aim for nutrient-rich foods. Adding plenty of fibre to your meals, such as whole grains, legumes, lentils, beans, fruits and vegetables, is a great start.
Research suggests that eating more fibre as part of a balanced diet can also help you maintain a healthy body weight throughout your life.
So, rather than making short-term changes in January, aim for small swaps you can stick with throughout the year.
Think like a health coach
Health psychologists have developed frameworks of behaviour change techniques that are known to help people change their physical activity and eating behaviour longer term. These evidence-based techniques are usually used by health coaches to support patients with lifestyle changes – but you can be your own coach by applying some of them yourself.
Examples include setting goals, making an action plan, identifying barriers, or teaming up with a friend or partner.
In practice, this could mean setting a goal to lose a realistic amount of weight per week incrementally (around one to two pounds per week), identifying the things that might get in the way of your goals, exercising with a friend and tracking your progress.
Quick-fix, low-calorie diet challenges might promise fast results, but they rarely deliver lasting change. Following evidence-based advice from the fields of psychology and nutrition can help you avoid the restrictive diet trap this January and achieve more sustainable, longer term lifestyle changes.
Sarah Hillier has previously received research funding from Slimming World (2019).
Chloe Casey 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.
Our beliefs aren’t fixed. They’re shaped, stretched and sometimes overturned by the ideas we encounter as we move through life. For many of us, books are the moments where that shift happens – a sentence that lingers, an argument that unsettles, a story that re-frames how we see the world. We asked 12 academic experts to share the book that challenged their assumptions and changed their thinking in a lasting way.
1. A Very Short Introduction to the Philosophy of Science (2002)
Induction lets us predict from patterns – if 11 eggs in a dozen are rotten, we expect the 12th to be rotten too. But as Hume notes, this reasoning is logically flawed: we justify induction by saying it has worked before, which is circular because it uses induction to defend itself.
This line of thought reshaped my views. There is no ultimate logical proof that induction works; I simply believe it does. In other words, I have faith in the scientific method.
Realising this stopped me fretting about how others reconcile science and religion. Faith and evidence coexist in my own thinking. I’m no more inclined to believe in a god, but I no longer have a problem understanding how faith and science can inhabit the same mind.
Mark Lorch is a biochemist, writer, and Professor of science communication
2. Nature is a Human Right, edited by Ellen Miles (2022)
Like so many others, I found myself gravitating back towards the natural world during the COVID pandemic, both in my academic work and my personal life. And I’d come to understand how disconnection and detachment from nature was harming the health and happiness of millions of people worldwide. But I hadn’t given much serious thought to equitable access to nature until I’d read Nature Is a Human Right.
The collection of essays and writings in this edited volume irrevocably convinced me that contact with, and access to, the natural world should not just be a privilege for some, but enshrined as a basic right for everyone.
The collection of ideas and arguments in this book – sometimes uncomfortable, sometimes upsetting – has persuaded me that we have to take action, not just to protect the natural world, but to ensure that contact with nature is a birthright for everyone.
Viren Swami is a professor of psychology
3. The Sketchnote Handbook by Mike Rhode (2012)
When I completed my PhD in 2012, I felt a strong pressure to adhere to a narrow view of computer science, where creativity and storytelling were often seen as superfluous. Then I attended a sketchnotes workshop, a practice I had never encountered before. Sketchnotes is a visual note-taking method that combines words and sketches to support creativity and memory recall.
The facilitator recommended Rohde’s book, and during my postdoctoral research, it quietly transformed my perspective. Joining the sketchnotes community, I met people from diverse backgrounds – teachers, chief technical officers and physicists – creating compelling visual stories. The book and community showed me that sketching should not be overlooked in computer science. Something I had always kept as a personal practice could become central to my research and teaching.
I challenged the stereotype of sketching as a “soft skill” and embraced it as a disciplined, creative and impactful way to understand people and their interactions with technology. Now, sketching is not just a tool, but a mindset that shapes everything I do.
Makayla Lewis is an senior lecturer of computer science (user experience)
4. Children of Time by Adrian Tchaikovsky (2015)
In Tchaikovsky’s novel, Earth has become uninhabitable and humanity spreads out into the stars in search of a new home. After much trial and error, we find a viable world – but it’s already home to a species of intelligent spiders.
I’m arachnophobic, so this novel might seem like an odd choice. However, Children of Time is told partly from the spiders’ perspective, and though they don’t think exactly like us, we can empathise with them as we follow the sometimes-painful growth of their civilisation, and their inevitable encounter with scary alien invaders – us.
I’m not claiming this novel to be a miracle cure, but it prompted me to reflect on my anxiety. I’m not going to get a pet tarantula anytime soon, but I’m more mindful of spiders than I was before. They really are quite fascinating little creatures when you get to know them.
Jack Fennell is a lecturer in English
5. On the Plurality of Worlds by David Lewis (1986)
Is the past real? How about the future? Common sense says no: the present encapsulates all existence. I used to agree. Then, in my early 20s, I read On the Plurality of Worlds. David Lewis’s metaphysical masterpiece changed my mind about many things, but most profoundly about time.
Lewis convinced me that time is analogous to space. Spatially distant objects (a café in Paris, a crater on Mars) are real, even if they aren’t “here”. Lewis argues time is identical. The past and future are merely temporal locations.
This leads to a stunning conclusion: Julius Caesar and the dinosaurs have just as much existence as you and I, even if they aren’t “now”. They haven’t vanished into nothingness. They are simply located elsewhere in the temporal dimension. The same applies to future things and events. Once I accepted this, I stopped seeing reality as a fleeting moment and began to see it as a vast, existing landscape of time. It was a complete conceptual shift that has remained with me ever since.
Benjamin L. Curtis is a senior lecturer in philosophy
6. Humankind: A Hopeful History and Utopia for Realists by Rutger Bregman (2019)
From criminal punishment to tax incentives, modern society assumes humans need guidance to avoid their worst instincts. Humankind by Rutger Bregman offers a very different perspective on our species and how peace can be achieved.
Have you ever felt embarrassed by blushing? You shouldn’t – blushing is a “superpower”. Our capacity to show shame helps form complex social bonds. History shows the most stable societies temper leaders’ ambitions and promote humility. Humans generally prioritise fairness over harm, and when violence occurs, it’s often due to hierarchy, not innate instinct. Bregman cites studies showing that leadership can reduce empathy, increase selfishness and encourage cheating.
The book challenged my view of government. I’d believed strong laws create order, but often it’s attempts to control others that empower strong leaders and cause instability. True social order comes from daily human relationships. A better world requires rethinking how we distribute power.
Michael Strange is an associate professor of international relations
7. Shikasta by Doris Lessing (1979)
When I was 18, Doris Lessing’s Shikasta first crossed my path. Even if I now, 46 years later, no longer remember the details of the plot, I still recall the unsettling feeling the novel gave me. It was as if I had glimpsed a dark future.
Materialism, egoism, war and unemployment thrived while deeper values as striving for collaboration or peace (ha!) vanished in to the air. When I read the book, I started to look upon the state of the world in new light. I wondered if the injustices on our planet could be avoided. And what we could expect in a nearby future.
I was both a bit scared and at the same time had the feeling that I had understood or seen something others didn’t talk about. For a long time, I waited to see Lessing’s vision unfold. Perhaps, in some ways, it now has.
Eva Wennås Brante is an associate professor in educational science
8. Sapiens by Yuval Noah Harari (2011)
Sapiens brilliantly weaves its author’s expertise in anthropology, behavioural science, geopolitics and socioeconomics into an enthralling, astute and thoroughly entertaining book that challenged, demolished and rebuilt my worldview. The unexpected ways creating, sharing and learning from stories have influenced who we trust, what we believe and how we govern ourselves, as individuals and as organised groups, are masterfully explained in the book.
In particular, the exploration of the impact of storytelling on our communities and the way we define, experience and shape culture fascinated me.
Harari draws from a wealth of real world examples that offer a fresh perspective on key historical events and core aspects of our societies that we routinely take for granted. I gained a new understanding of life and how to live it.
Alina Patelli is a senior lecturer in applied artificial intelligence
9. 50 Simple Things You Can Do to Save the Earth (1990)
In the 90s, my father gave me 50 Simple Things You Can Do to Save the Earth by the Earth Works Group. It started with short summaries on global environmental concerns at the time (the hole in the ozone layer, pollution, biodiversity loss). But then, importantly, it proceeded to give readers ideas about practical changes in their lives they could do to address those global concerns.
As a child, this book taught me that these were global issues but that my actions mattered, that we all had the power to help our natural world. It changed my mind about who can solve global problems and helped set me on a path to get involved in environmental conservation, which eventually became a career in marine climate change research. Today, this experience tells me that it is never too early to start thinking about what we as individuals can do for nature.
Ana M. Queirós is a professor in climate change and marine biology
10. Man’s Search for Meaning by Viktor Frankl (1946)
During my postdoctoral research, I was drawn towards Holocaust testimonies including Survival in Auschwitz by Primo Levi (1947) and Night by Elie Wiesel (1956). These are powerful, remarkable memoirs, but the book that redirected my thoughts was Viktor Frankl’s Man’s Search for Meaning.
Holocaust testimonies explore the experience of struggle, the shock of witnessing the unthinkable, the terrifying logistics of a genocide. But Man’s Search for Meaning also offers the reader an insight into Frankl’s enlightened psychological perspective as this book was written while he was still inside the camp, rather than as a reflection afterwards.
Frankl was an established psychiatrist when sent to Auschwitz, but his reflections on the meaning of abject psychological and physical suffering pushed him into philosophical territory. In the darkest place on Earth, he found an existential truth: A person can “choose one’s attitude in any set of given circumstances, to choose one’s own way”. He refers to this choice as “the last inner freedom … a spiritual freedom” in the face of despair and death.
Laura Stephenson is a senior lecturer in film
11. The Concept of the Mind by Gilbert Ryle (1949)
Pre-eminent among the books that have forever changed my thinking is Gilbert Ryle’s The Concept of Mind. In medical school I learnt all about the human sciences but was baffled by psychology, a parallel universe where the laws of physics didn’t seem to apply. Ryle explained that there’s no “ghost in the machine” but that we can describe our one world using a physical or a psychological vocabulary.
When I worked as a psychiatrist, The Concept of Mind showed me that different models of mental illness based on neurophysiology or psychoanalysis or behaviourism or social rehabilitation could all, in principle, be correct.
So I was free to help change patients minds by altering their neurochemistry or by psychological means, confident that their brains would also heal.
Ryle implies that inferences about mental facts should be as carefully drawn as those about physical phenomena. But it has seemed to me, as a mental capacity law researcher, that the process of inferring capacity is tortuous and irretrievably subjective. The Concept of Mind has given me the confidence to challenge the law and to provide radical alternatives. I am greatly in Gilbert Ryle’s debt.
Jonathan Fisk is a PhD candidate in law
12. The Mushroom at the End of The World by Anna Tsing (2015)
We are not used to reading stories without human heroes – and yet, as researchers, these are exactly the narratives we often reproduce. During my PhD, I spent four months in Botswana and South Africa chasing tails (and tales) of African wild dogs. For me, this is where Anna Tsing’s work came alive.
Though much of the research in my field tells us that non-human beings are active participants in shaping encounters and environments, this co-production is rarely extended to our work. The Mushroom at the End of the World asks us to “bring back curiosity”, noticing beyond seeing, opening up a multi-sensory world of presence and possibility.
In the field, this meant adapting my methods in situ, incorporating sound and smell to attend to wild dogs’ ways of moving through and understanding space. This counter-mapping transgresses imagined human boundaries and paths, opening up ways to research and respond to more-than human worlds.
Anna Bedenk-Smith is a lecturer in human geography
Has a book ever changed your mind? Let us know in the comments below
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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.
Source: The Conversation – UK – By Bamo Nouri, Honorary Research Fellow, Department of International Politics, City St George’s, University of London
Tehran has said it is ‘ready for war’ after Trump’s threats of US military action.Lucas Parker / Mr Changezi / Shutterstock / Canva
Donald Trump is weighing military action in Iran over the state’s crackdown on protesters. Reports suggest that more than 600 people have been killed since the protests began in late December, with the US president saying the US military is now “looking at some very strong options”.
Trump has not yet elaborated on what these options are and has said that Iranian officials, keen to avoid a war with the US, had called him “to negotiate”. But he added that the US “may have to act before a meeting” if the deadly crackdown continues.
There is a wide spectrum of measures available to Washington should it decide to intervene in Iran. These range from diplomatic condemnation and an expanded sanctions regime, to cyber operations and military strikes. However, history weighs heavily against every move the US government may be considering.
Targeted sanctions and diplomatic pressure, which includes the 25% tariff rate recently introduced by Trump on any country that does business with Iran, remain the least escalatory tools. They allow the US to coordinate with its allies and signal moral support for protesters in Iran without triggering direct confrontation. Yet decades of experience show the limits of this approach.
Iran’s leadership has mastered how to absorb economic pressure, shift costs on to society and frame longstanding western sanctions as collective punishment imposed by hostile outsiders. The government in Tehran has adapted over time by developing alternative markets and expanding informal and non-dollar trade.
It has also boosted its economic resilience through regional networks, particularly in Iraq where political, financial and security ties help sustain revenue flows and cushion the impact of sanctions on the state.
There are other, more covert tools at Washington’s disposal, including cyber disruption and efforts to assist independent media or help protesters bypass internet shutdowns. These measures can help protesters stay visible internationally and complicate the state’s capacity to ramp up repression.
However, even here expectations should be modest. These tools may create friction within the Iranian elite by raising the costs of, and imposing technical difficulties on, surveillance and repression. But they do not change the core calculus of a regime that prioritises survival above all else.
At the most extreme end of the spectrum are military strikes. The rationale behind strikes would be to undermine the regime’s repression efforts. But in reality, they risk doing the opposite. Iran’s ruling system, and particularly the powerful Islamic Revolutionary Guard Corps branch of the armed forces, has historically relied on external threats to consolidate power domestically.
A preemptive US strike would almost certainly hand Iran’s security apparatus the very narrative it seeks: an existential battle for national survival. This framing is already explicit in the discourse of the Iranian elite.
Mohammad Bagher Ghalibaf, the hardline speaker of the Iranian parliament, warned in a recent speech that any attack on Iran would make Israel and all US military bases and assets in the region “legitimate targets”. Iranian state media then showed large crowds of regime supporters rallying in Tehran and other cities, chanting “Death to America” and “Death to Israel.”
Military escalation is especially dangerous given the character of the current protest movement. Women have been at the forefront, challenging the ideological foundations of the state, while regions populated largely by ethnic Kurds have endured disproportionate levels of violence at the hands of the authorities.
These protests are civic, decentralised and rooted in social grievances. US military strikes would allow the Iranian state to overwrite that reality, recasting a diverse domestic movement as a foreign-backed security threat. In doing so, it would legitimise a far harsher crackdown than anything seen so far.
Shadow of 1953
Many ordinary Iranians are also cautious of direct US interference. This stems from a CIA-backed coup in 1953 that ousted Iran’s elected prime minister, Mohammad Mosaddeq, and restored the monarchy under Shah Mohammad Reza Pahlavi. The coup was followed by nearly two decades of repression, political policing and authoritarian rule closely aligned with western interests.
This experience is not distant history; it is a foundational trauma that continues to shape Iranian political consciousness. As a result, recent suggestions by Trump that the collapse of Iran’s theocratic system would naturally make way for a democratic transition cannot be disentangled from the memory of an external intervention that produced dictatorship rather than self-rule.
It also explains why many people inside Iran are sceptical of figures such as Reza Pahlavi, the son of country’s last shah who has often been promoted in the west as a possible future leader of Iran. Pahlavi remains symbolically tied to a system associated with oppression and foreign backing. This leaves him without the broad domestic legitimacy required for any credible democratic transition, regardless of his messaging.
The scepticism of Iranians is reinforced by recent regional experiences. In Iraq, foreign intervention hollowed out the state, leaving a weak system that has been co-opted by external powers and militias.
And in Syria, the collapse of central authority paved the way for a former al-Qaeda leader, Ahmed al-Sharaa, to take power. He has been rebranded by western powers, including Trump, into a credible political figure despite his jihadist past.
These cases reinforce a belief across the Middle East that western intervention tends not to empower democratic forces. It instead appears to elevate the most organised and militarised parties to power, producing long-term instability rather than renewal.
Without a credible, homegrown transition, Iran risks fragmenting and sliding into chaos. For Washington, the most difficult reality may be that the wisest path is not bold intervention, but restraint combined with sustained support for Iranian society.
Genuine change in Iran cannot be engineered from the outside, especially at the point of a missile.
Bamo Nouri 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.
Imagine a map that allows you to see what your neighborhood looked like a century ago in immense detail. What you’re thinking of is probably very much like the fire insurance maps produced from the 1860s to the 1970s for insurance companies to identify potential fire risks.
Often referred to as Sanborn maps, after the Sanborn Map Co. that produced them, fire insurance maps were created for every city in the United States with a population greater than 1,000 people. Over a century, more than 50,000 editions of these maps were produced, comprising over 700,000 map sheets – many of which have been scanned and are publicly accessible through the Library of Congress.
1917 Sanborn map of The Hill at the University of Tennessee, Knoxville. Library of Congress
Genealogists, historic preservationists, historians and urban planners commonly use these maps to understand past urban landscapes. But as a critical cartographer interested in how maps shape how people understand the world, I see these maps differently.
Fire insurance maps supply more than just detailed insights into how neighborhoods looked decades ago. Needing to turn a profit, insurers sought to minimize the amount of risk they underwrote or charged higher premiums to account for risk. These maps provide important clues into how insurance companies understood how risk was distributed across cities, revealing costly biases.
Mapping fire risk
Before zoning and land-use planning, American cities frequently mixed industrial, commercial and residential buildings in the same block. Insurance agents used the immense detail of fire insurance maps to determine whether a property was too risky to underwrite, often weighing the demographics of the neighborhoods with the flammability of the buildings in the neighborhood.
For example, an Atlanta neighborhood called Lightning was a Black, working-class district composed of a mixture of rail yards, noxious industries and residences in 1911. The neighborhood was also an immense fire hazard. Atlanta’s primary trash incinerator stood less than 150 feet from two massive natural gas storage tanks, while two gas processing plants manufactured specialized fuels just feet from homes.
Underwriters would use information from fire insurance maps to understand the local landscape. In these maps, colors correspond to the building’s construction material: pink indicates brick, while yellow indicates wood. Lightning was primarily made from wood, placing the entire neighborhood at risk if a fire broke out.
Fire insurance maps and discrimination
At the same time, fire insurance maps also highlight the social landscape of the neighborhood.
Many buildings in the Lightning fire insurance map are labeled “F.B.,” which stands for “female boarding,” a euphemism for brothels. While brothels were not a fire risk themselves, this code indicated the alleged moral hazard of a neighborhood, or the likelihood that property owners would allow riskier activities to occur on their property that could cost insurers more.
1911 Sanborn map of the Lightning neighborhood of Atlanta, Ga. It’s now Mercedes-Benz Stadium, home to the Atlanta Falcons of the National Football League and the Atlanta United FC of Major League Soccer. Library of Congress
From this one map, an underwriter could quickly see that Lightning was an extremely risky place to insure. Along with disinvestment from fire insurers, marginalized communities like Lightning also experienced other forms of systemic discrimination. Scholars have documented racial discrimination in car, life and health insurance underwriting.
Although fire insurance maps are no longer used in the insurance industry, they provide researchers one way of seeing how discrimination in fire insurance and urban planning manifested in the United States during the 20th century.
Jack Swab does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
Source: The Conversation – in French – By Christoph Grunau, Professeur des Universités, expert en épigénetique environnementale, Université de Perpignan Via Domitia
Les schistosomes, de petits vers parasites, sont à l’origine d’une maladie aux conséquences potentiellement graves : la schistosomiase ou bilharziose. Une simple baignade dans des eaux infestées par leurs larves peut suffire à être contaminé. Longtemps cantonnée à certains pays tropicaux, la maladie s’étend. Elle aborde désormais le sud de l’Europe : des cas ont été recensés en Corse, ces dernières années.
Plus de 240 millions de personnes dans le monde vivent avec un parasite dans le corps sans le savoir. Ces personnes sont infectées par des vers plats appartenant au genre Schistosoma, transmis par des escargots d’eau douce. Ils sont responsables d’une maladie appelée schistosomiase ou bilharziose, dont les complications peuvent être graves, allant jusqu’au cancer du foie ou de la vessie.
Si la grande majorité des personnes touchées vivent en Afrique, en Amérique latine ou en Asie, des foyers localisés ont également été récemment signalés en Europe, notamment dans le sud-est de la Corse.
Aujourd’hui, la lutte contre la bilharziose ne constitue donc plus seulement un enjeu de santé publique locale. Il s’agit d’un défi mondial, qui exige une veille épidémiologique accrue, une coopération internationale renforcée et des stratégies adaptées à une réalité environnementale en mutation.
Une même maladie, différentes manifestations.
La bilharziose est transmise par de petits escargots aquatiques vivant dans les eaux douces. Les larves de schistosomes les infectent, puis se multiplient dans leur organisme, avant d’être libérées dans les eaux environnantes.
Elles vont alors se mettre en quête de leur hôte final, un mammifère (rongeur, bétail, être humain…) immergé à proximité. Une fois à son contact, les larves percent sa peau et pénètrent dans son corps. Après un passage par le foie, elles se transforment en adultes, et s’installent dans les veines proches de l’intestin ou de la vessie.
Si, dans certains cas, les premiers stades de l’infection peuvent se traduire par une irritation de la peau ou de la fièvre, souvent la maladie reste silencieuse pendant des mois.
Les manifestations cliniques qui surviennent ensuite sont principalement liées aux centaines d’œufs produits chaque jour par les femelles. En effet, si une partie est éliminée en même temps que les matières fécales ou les urines (et peuvent donc à nouveau contaminer les eaux), certains restent piégés dans les tissus. Des lésions et des réactions inflammatoires se produisent, qui peuvent avoir de lourdes conséquences.
Cependant, la bilharziose ne se manifeste pas de la même façon partout. En effet, la forme de la maladie varie non seulement selon l’espèce de vers parasites impliquée, mais aussi selon l’espèce d’escargots qui les transmettent, ainsi qu’en fonction des saisons de transmission, propres à chaque région, ou encore des mesures de contrôle, très dépendantes des infrastructures locales.
Type de maladie
Symptômes
Espèce impliquée
Répartition géographique
Schistosomiase intestinale
– typiques: douleurs abdominales, diarrhée, et sang dans les selles;
– atteintes avancées: hépatomégalie (augmentation du volume du foie), parfois associée à une ascite (liquide péritonéal) et une hypertension de la veine porte qui augmente le risque d’hémorragie; une splénomégalie (augmentation du volume de la rate) peut aussi être observée. Risque de cancer du foie aux stades tardifs.
Schistosoma mansoni
Afrique, Moyen-Orient, Caraïbes, Brésil, Venezuela et Suriname
Schistosoma japonicum
Chine, Indonésie, Philippines
Schistosoma mekongi
Plusieurs districts du Cambodge et de la République démocratique populaire lao
Schistosoma guineansis et S. intercalatum (espèce voisine)
Zones des forêts tropicales humides en Afrique centrale
Schistosomiase urogénitale
– typiques: hématurie (sang dans les urines);
– atteintes avancées: lésions rénales, fibrose de la vessie et de l’uretère, et risque de cancer de la vessie aux stades tardifs.
Schistosoma haematobium
Afrique, Moyen-Orient, France (Corse)
Dans certains cas d’infection aiguë, des manifestations atypiques (paralysies) ont également été décrites. Chez les enfants, l’infection se traduit par une anémie (car les parasites se nourrissent des cellules sanguines de leur hôte) ainsi que par un retard de croissance.
Pour éviter la transmission de la maladie, outre les gestes individuels (voir encadré « Comment se protéger »), les programmes locaux de lutte contre les escargots et de sensibilisation communautaire sont essentiels, car ils permettent de rompre le cycle de transmission du parasite. Dans les zones endémiques, la participation aux campagnes de traitement collectif au praziquantel permet en outre d’éviter les formes chroniques.
Cette parasitose, bien que connue depuis longtemps, demeure malheureusement d’actualité. Chaque nouveau barrage ou projet d’irrigation, chaque communauté dépourvue d’assainissement créent les conditions pour une transmission renouvelée. Une situation encore aggravée par les modifications liées au changement climatique en cours, ou au développement de certaines pratiques, parmi lesquelles l’écotourisme, qui, en favorisant les voyages dans des zones rurales ou naturelles parfois peu surveillées sur le plan sanitaire, accroît le risque d’exposition à des eaux contaminées par les schistosomes.
Au sein de notre laboratoire, et en collaboration avec des centres de recherche en Europe, Amérique du Nord et Amérique du Sud ainsi qu’en Afrique de l’Ouest, nous travaillons à comprendre la dispersion des parasites et des mollusques vecteurs. Nous étudions aussi la possibilité d’améliorer la résistance des escargots contre le parasite, et nous explorons la possibilité de recourir à des modifications épigénétiques et génétiques pour rendre les parasites vulnérables.
Un parasite qui s’adapte aux activités humaines
Le cycle de la bilharziose repose sur trois éléments : le parasite, l’escargot, et l’eau. Dès que ces trois conditions sont réunies, la transmission est possible. Que ce soit dans les campagnes brésiliennes, le Nil en Égypte, les rizières asiatiques ou les rivières corses, la bilharziose s’adapte aux paysages humains.
En Afrique de l’Ouest, comme au Sénégal et au Bénin, les écosystèmes fluviaux et les températures élevées qui varient peu tout au long de l’année constituent des habitats idéaux pour les escargots appartenant aux espèces Biomphalaria et Bulinus, vecteurs des formes intestinale et urinaire de la maladie. Dans ces régions, la transmission est observée tout au long de l’année. Elle est plus importante au sein des populations ayant un contact intense avec l’eau, comme dans la ville fluviale de Ganvié (Bénin).
Pêcheurs et habitants en pirogue dans la lagune de Ganvié, au Bénin. Ce type d’environnement, où l’eau douce est omniprésente et les contacts humains fréquents, constitue un terrain propice à la transmission de la bilharziose. Ronaldo Augusto, CC BY
Au Brésil, la forme intestinale prédomine. En général, les escargots vecteurs, principalement Biomphalaria glabrata, prolifèrent dans les réservoirs d’eau, les rivières et les lagunes. Les épidémies surviennent principalement dans les communautés rurales du Nord-Est et du Sud-Est, où l’accès à l’eau potable et à l’assainissement de base est souvent insuffisant.
Cependant, il est surprenant de constater que des épidémies peuvent apparaître dans les zones urbanisées, soit en raison de systèmes d’assainissement défaillants, soit parce que des rongeurs se trouvent à proximité de collections d’eau douce. Malgré le succès des programmes de lutte, cette complexité fait de la bilharziose une maladie dynamique, capable de s’adapter à différents scénarios selon la région du Brésil considérée.
Ces deux images prises dans l’État de Tocantins, au nord du Brésil, présentent deux scénarios contrastés de schistosomiase. Deux environnements endémiques distincts sont représentés : l’un, situé dans un parc naturel, où la transmission est principalement maintenue par la faune sauvage (photo de gauche). L’autre, en zone urbaine, se caractérise par la présence d’habitations et une dynamique de transmission dominée par les rejets de déjections humaines non traitées (photo de droite). Ronaldo Augusto, CC BY
En Asie, la situation est encore plus complexe. En effet, l’espèce qui y sévit, Schistosoma japonicum, présente une capacité particulièrement marquée à contaminer de nombreux hôtes mammifères (elle infecte aussi bien les humains que les bovins et les rongeurs). Le risque d’infection est renforcé par les systèmes agricoles traditionnels, notamment la riziculture et l’élevage bovin, qui favorisent des contacts étroits et durables entre humains, animaux et milieux aquatiques (l’escargot vecteur, Oncomelania hupensis, vit dans les rizières et les zones humides). Cette situation complique fortement les efforts de contrôle. Par ailleurs, chaque inondation peut ouvrir de nouvelles zones de transmission.
Même dans les régions hors des zones tropicales, la bilharziose peut surprendre. C’est par exemple le cas en Corse, ou des touristes ont contracté la maladie après avoir nagé dans la rivière Cavu, entre 2013 et 2022.
Des analyses ont confirmé la présence sur l’île d’escargots Bulinus truncatus et du parasite S. haematobium, probablement introduit par des voyageurs en provenance de zones endémiques au Sénégal. Cet épisode a révélé la vulnérabilité de certains écosystèmes européens.
Une menace ancienne dans des paysages qui changent
Bien plus qu’une simple maladie tropicale, la schistosomiase est un indicateur des inégalités socio-économiques et de la manière dont nos environnements conditionnent notre santé. La comprendre, c’est aussi comprendre la façon dont s’entrelacent infrastructures, climat et comportements humains.
Mieux connaître cette maladie, et mettre au point des moyens de lutte efficace devient d’autant plus crucial que le changement climatique en cours favorise sa propagation. La hausse des températures et les modifications des régimes de pluie créent de nouveaux habitats propices aux escargots vecteurs. C’est aussi le cas de la pression sur les ressources en eau, qui conduit souvent à la création de barrages, de retenues artificielles et de systèmes d’irrigation. Autant d’aménagements générant des zones d’eau calme ou faiblement renouvelée, particulièrement favorables au développement desdits escargots.
Conséquence : de nouvelles zones de transmission pourraient apparaître là où le risque était jusqu’à présent considéré comme nul. Des modèles prédictifs suggèrent déjà que certaines régions du sud de l’Europe, notamment autour du Bassin méditerranéen, pourraient présenter les conditions écologiques nécessaires à l’établissement du cycle de transmission du parasite.
Il faut savoir que le parasite ne s’implante durablement dans une région que si l’hôte intermédiaire est présent et si les conditions climatiques sont favorables. Or plusieurs espèces d’escargots vecteurs, dont Planorbarius metidjensis et Bulinus truncatus, sont déjà présentes dans certaines régions d’Europe méridionale, ce qui explique un potentiel d’établissement localisé mais réel.
La réémergence de la bilharziose en Corse illustre comment cette maladie pourrait cesser d’être perçue uniquement comme une maladie tropicale négligée et commencer à être reconnue comme une infection émergente, y compris dans les pays du Nord.
Christoph Grunau a reçu des financements de l’ANR, de Wellcome Trust, de la Région Occitanie, et de l’UPVD.
Ronaldo Augusto a reçu des financements de l’ANR, de la Région Occitanie, et de l’UPVD.
