Category: English

Source: The Conversation – UK – By Manal Mohammed, Senior Lecturer, Medical Microbiology, University of Westminster

A food truck in southern Italy recently became the centre of a deadly health scare. A food-borne outbreak linked to preserved vegetables killed two people and sent more than a dozen to hospital.

At the same time, the UK’s Food Standards Agency warned shoppers to avoid jars of broccoli from a specific batch code, fearing they too could contain the same hidden danger, Clostridium botulinum, the bacterium that produces the toxin responsible for botulism – one of the deadliest food-borne illnesses known.

The canning process removes air from food and seals it tightly, creating an oxygen-free (anaerobic) environment. This is normally what keeps food safe for long storage – but it also creates the perfect conditions for C botulinum. Unlike many bacteria, it doesn’t need oxygen to grow.

Its spores, which are commonly found in soil, can survive cooking and processing. In low-acid foods such as broccoli, green beans, corn, beets and peas, if the canning process isn’t hot enough or long enough, those spores can “wake up”, multiply and release their toxin. Because the toxin is invisible, tasteless and odourless, contaminated food can look and smell perfectly normal while being deadly.

Botulism is rare but extremely serious and even a tiny amount can be deadly – just two nanograms per kilogram of body weight can be fatal.

The spores themselves are usually harmless if swallowed. But in an anaerobic environment they can germinate and release toxin. That’s why homemade preserved foods are a common cause of outbreaks.

Why botulism is so dangerous

Botulism is caused by a neurotoxin that attacks the nerves, leading to muscle weakness, breathing difficulties, paralysis, and, in severe cases, death. Symptoms usually appear within 18 to 36 hours of eating contaminated food, but can range from six hours to ten days.

Early signs include difficulty swallowing or speaking, drooping eyelids, blurred or double vision, facial weakness, vomiting and progressive muscle paralysis, which can cause respiratory failure.

Diagnosis is tricky, as symptoms can mimic other conditions, including stroke, Guillain-Barré syndrome (a rare autoimmune disorder where the body’s immune system attacks the nerves), and myasthenia gravis (a chronic condition that causes muscle weakness due to problems with communication between nerves and muscles). Doctors usually confirm botulism through clinical assessment and laboratory testing of serum, stool or food samples.

The main treatments for botulism are supportive care and antitoxin. Supportive care means treating the complications of the illness — for example, patients may need a ventilator if they develop breathing difficulties, or help managing infections. Antitoxin is a medication that binds to and neutralises the toxin circulating in the body. If given early, it can stop the toxin from causing further harm, though it cannot reverse damage already done. Survivors often face long recoveries with lingering fatigue and breathing problems.

There are simple but vital ways to reduce the risk of foodborne botulism. First, never eat food from cans or jars that are dented, bulging, leaking, or discoloured. If you can your own low-acid foods, make sure you boil them for ten minutes before eating to kill spores. And make sure use proper pressure canners and always follow tested canning instructions.

When in doubt, throw it out.

A deadly toxin with a double life

Despite its dangers, botulinum toxin also has important medical uses. When injected in minute, controlled doses, botulinum toxin can reduce muscle spasticity (a condition where muscles tighten or stiffen abnormally), treat chronic migraines, and manage conditions such as strabismus (crossed eyes) and cervical dystonia (a painful condition where the neck muscles contract involuntarily). The US Food and Drug Administration first approved it for medical use in 1989, and it has since been authorised for a wide range of treatments.

Botulinum toxin works by blocking nerve signals that trigger muscle contraction, smoothing wrinkles and fine lines, and has become a global cosmetic phenomenon. But the same toxin that has medical and aesthetic benefits can also cause catastrophic harm if misused. Unlicensed or poorly regulated injections are risky – and in August 2025, botulinum toxin was linked to a deadly outbreak in the UK.

Food-borne botulism is rare but deadly. Prevention depends on safe food handling, proper canning and avoiding suspicious-looking jars and cans. And while botulinum toxin has life-saving medical uses and cosmetic appeal, outside of controlled and licensed conditions it remains one of the most lethal substances on earth.

Manal Mohammed does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Why preserved vegetables can turn deadly – and how to stay safe – https://theconversation.com/why-preserved-vegetables-can-turn-deadly-and-how-to-stay-safe-263161

Source: The Conversation – UK – By Elna Heimdal Nilsson, Professor of Aeronautical Sciences, Department of Aviation and Aeronautical Sciences, Lund University

Military aircraft – from fighter jets to transport planes – are playing a significant role in today’s unstable world. Cumulatively, the operations carried out by these fleets, from combat missions to training flights, consume large amounts of fossil fuel.

Nevertheless, military aviation is rarely included in national climate inventories. In addition to greenhouse gases, aviation also emits other pollutants such as soot and particles, which affect both climate and air quality, and have detrimental effects on human health and ecosystems.

Recently, the UK government announced that it would purchase 12 F-35A fighter aircraft, some of which will be used to reduce a backlog in pilot training. The F-35A is the standard variant of the F-35 fighter jet.

While the decision is primarily motivated by defence and alliance commitments, it also has environmental implications. Expanding training activities will increase the number of flight hours, and consequently, fuel use and emissions. Fighter jets consume large quantities of fuel per flight hour.

The combustion process in aircraft engines releases carbon dioxide (CO₂), but the impact on the climate and environment extends further: emissions of soot particles, nitrogen oxide compounds, water vapour and sulphuric compounds influence atmospheric chemistry and cloud formation.

The persistent contrails and the cirrus clouds they generate are estimated to cause an impact on the climate comparable in magnitude to the warming effect of CO₂ from commercial aviation.

Any assessment of mitigation options must therefore consider both CO₂ and non-CO₂ effects arising from aircraft engine combustion. To mitigate aviation-related climate effects, the civil aviation sector has been promoting the development of sustainable aviation fuels (SAF).

When produced from waste oils or residues, hydroprocessed esters and fatty acids (Hefa) fuels – which are forms of sustainable aviation fuel – typically achieve 50–70% lower life-cycle CO₂ emissions compared with fossil-based jet fuel. Synthetic aviation fuels known as advanced power-to-liquid (PtL) e-fuels, produced using renewable electricity, could reduce emissions by more than 80%, though they are not yet available at scale.

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

In addition to a lower carbon footprint compared to fossil fuels, SAFs have
also been shown to produce fewer soot particles during combustion, reducing the likelihood and severity of contrails and cirrus clouds.

For technical reasons, down to the specific molecular composition SAF compared to fossil based jet fuel, commercial SAFs are currently not certified as standalone fuels. However, they are available for blends of up to 50% along with fossil-based jet fuels.

The quality of the sustainable fuels is very high and there is no technical barrier to their use in military aviation. The question is: to what extent can the climate and environmental impact of military aviation operations be reduced if sustainable aviation fuels are introduced?

Sustainable fuel and the F-35

Let’s take the example of the F-35, which was the aircraft purchased recently by the UK government. Under certain conditions, the F-35 can burn five tonnes of jet fuel in a single sortie lasting an hour. For comparison, a diesel car like the Volvo V70 would, in its whole lifespan, burn an amount of fuel corresponding to just four hours of combat manoeuvring with the F-35.

Technically, the F-35 is already approved to operate on blends of conventional kerosene and certified synthetic fuels. Similar to civil aviation standards, military standards allow for blending ratios of up to 50%, depending on the production pathway.

No modifications to engines or fuel systems are required. F-35 flights that used commercially available fuel with 40% SAF were carried out by the Norwegian Air Force in early 2025.

There are no significant technical barriers to the new F-35A aircraft entering UK service to operate on commercially available SAF blends with up to 50% renewable fuel. Compatibility is not the limiting factor, but, unfortunately, the availability and cost of fuel are.

For military training flights, which may involve large numbers of sorties, SAF can therefore provide significant reductions in life-cycle greenhouse gas emissions. A 50% blend of Hefa, for instance, could cut average CO₂ emissions per flight by around one third.

Since contrails can account for a large fraction of aviation’s total climate impact, this effect is potentially important. The strategic allocation of SAF to flights that are most likely to generate persistent contrails, like training missions at high altitude in humid conditions, could amplify the climate benefit of limited SAF supplies.

The UK’s acquisition of additional F-35A aircraft will help address a backlog in pilot training, but it will also increase emissions. From both a climate and national security perspective, SAFs represent the most practical near-term mitigation option.

The F-35 is technically compatible with sustainable aviation fuels – and substantial life-cycle emission reductions are achievable this way. Additional benefits may come from reduced contrail formation. However, limitations in global SAF production and their higher costs restrict the extent to which these fuels can currently be deployed.

SAFs will not make military aviation climate neutral, but they could substantially reduce its environmental footprint at a time when both security and sustainability are pressing concerns.

Elna Heimdal Nilsson 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. Sustainable fuels could reduce the climate impact of military aircraft – https://theconversation.com/sustainable-fuels-could-reduce-the-climate-impact-of-military-aircraft-264792

Source: The Conversation – UK – By Sarah A. Walker, Assistant Professor of Educational Psychology, Durham University

You’ve probably seen the word “narcissist” thrown around online in headlines, on dating apps or in therapy-themed TikToks. But the label that people often unthinkingly slap on toxic bosses or reality TV villains hides a much more complicated psychological picture.

Psychologists have studied narcissism for many years, but over time, our understanding has evolved. One of the biggest changes is that today, narcissism is no longer seen as just grandiosity, arrogance or egotism.

Early scientific descriptions of narcissism focused on dominance, ambition and self-importance, all of which are traits associated with traditional masculine stereotypes. That meant narcissistic tendencies in women were often misread or overlooked. When those traits show up as emotional sensitivity, insecurity or relational manipulation, they sometimes still are misdiagnosed as anxiety, mood disorders or borderline personality disorder traits.

The most extreme and persistent forms of narcissism can sometimes be diagnosed as narcissistic personality disorder. This condition was added to the Diagnostic and Statistical Manual of Mental Disorders, the American Psychiatric Association’s diagnostic manual, in 1980. But most people with narcissistic tendencies won’t meet the threshold for a diagnosis.

So what does the research actually say?

Narcissism in general is now understood as a complex set of personality characteristics that can show up in different ways.

Psychologists had long suspected that there might be different kinds of narcissism, but it wasn’t until 1991 – when researcher Paul Wink and his colleagues presented a model including grandiose and vulnerable subtypes – that they were more formally recognised. Although there are other models, this remains one of the more popular approaches to understanding narcissistic tendencies in the wider population.

A 2021 review by US psychologist Joshua Miller and his colleagues pulled together decades of research to offer one of the most authoritative summaries of how psychologists now understand narcissism. It explains that narcissism has a common foundation, which includes things such as self-importance and entitlement. It then branches into different forms of narcissism, such as grandiosity, antagonism and vulnerability.

Researchers now often use the terms grandiose and vulnerable to describe two major forms of narcissism. One person with narcissistic traits may be bold with high levels of grandiose traits, confidence and emotional resilience. Another might be defensive, anxious and hypersensitive to criticism. Both show signs of narcissistic self-focus, but they end up looking quite different in how they experience and express emotion.

In a 2022 research paper I wrote with colleagues, we carried out the first meta-analysis examining how narcissistic traits relate to the ability to control one’s emotions. The results showed that vulnerable narcissism is consistently associated with greater emotional difficulty, which means these people might find it harder to keep their emotions in check.

In particular, people with high scores on vulnerable narcissism scales are more likely to rely on suppression. Suppression is a strategy that people use to hide or inhibit their emotional expressions, and has been linked to poorer wellbeing. On the surface, suppression might sound like self-control.

In some situations, it can be. For example, keeping a lid on your emotions when your boss is yelling at you. But trying to mute emotional expression without addressing the underlying emotions increases stress when it becomes our default strategy. It can worsen mental and physical health over time.

In contrast, grandiose narcissism wasn’t linked with emotion regulation difficulties. In fact, several of the studies included in our analysis suggest that people with higher levels of grandiose traits may not experience as much emotional distress in the first place. This challenges the popular idea among researchers that people who exhibit narcissistic tendencies are also experiencing emotional instability.

Emotional intelligence and self-perception

The differences between forms of narcissism show up in emotional intelligence research as well. In a 2021 systematic review on narcissism and emotional intelligence, my colleagues and I found that people with grandiose traits often said they were good at understanding and managing emotions. For instance, how well they think they can handle anger or recognise other’s emotions.

But when their skills were tested using emotion tasks (such as recognising facial expressions or identifying the best way to respond to an emotional situation), their performance didn’t always match up with how skilled they said they were. This is consistent with a 2018 study which also found that people with grandiose tendencies rated themselves as emotionally skilled but performed worse on skill-based emotional intelligence tasks compared to other participants.

In contrast, people with vulnerable narcissistic traits tend to rate themselves lower in emotional intelligence, and seem to genuinely struggle more with managing emotions in everyday life.

So what should we make of all this?

It’s time to move beyond the pop-psych trend of labelling difficult people as narcissists. Narcissism isn’t about taking too many selfies. And no, the partner who ghosted you or the colleague who dominates meetings isn’t necessarily high in narcissistic traits either – no matter how much we might like to complain about them over coffee.

These kinds of casual diagnoses aren’t just unhelpful, they’re often wrong.

Narcissism is a complex psychological pattern that can show up in different ways and can reflect a deeper struggle with things such as self-esteem, emotion regulation and social connection. Understanding this doesn’t excuse people’s bad behaviour – not at all. But it does help us look past the stereotypes to get a clearer picture of what narcissistic traits look like in everyday life.

Sarah A. Walker 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 we’ve learned about narcissism over the past 30 years – https://theconversation.com/what-weve-learned-about-narcissism-over-the-past-30-years-258505