Malnutrition : utiliser les déchets organiques pour lutter contre la « faim cachée »

Source: The Conversation – in French – By Jean-Michel Médoc, Chercheur agronome de la gestion territoriale des déchets organiques, Cirad

Parcelles de niébé et de patate douce à chair orange agroécologiquement biofortifiées à Nioro du Rip, au Sénégal. Jean-Michel Médoc, Fourni par l’auteur

Dans le monde, 1,6 milliard de personnes souffrent de carences en micronutriments. Cette « faim cachée » touche principalement les enfants, les adolescents et les femmes en âge de procréer. Pour la combattre, les déchets organiques, combinés à des microorganismes locaux, peuvent être mobilisés pour améliorer la qualité nutritionnelle des produits de récolte.


Selon l’Organisation mondiale de la santé (OMS), la malnutrition désigne les déséquilibres dans l’alimentation. Contrairement à l’idée que l’on s’en fait généralement, la malnutrition concerne donc non seulement les carences, mais aussi les excès en nutriments.

Il existe deux formes de malnutrition, très différentes l’une de l’autre : la dénutrition (qui englobe le retard de croissance, l’émaciation – une perte excessive de poids – et les carences en micronutriments) et le surpoids ou l’obésité (qui résulte d’un excès de graisses corporelles).

En 2022, 881 millions d’adultes souffraient d’obésité, et plus de 148 millions d’enfants de moins de 5 ans souffraient de retard de croissance, tandis que 45 millions étaient atteints d’émaciation.

En outre, on estime que, sur la planète, 1,6 milliard de personnes souffrent de carences en micronutriments. Celles-ci peuvent avoir de lourdes conséquences sur la santé.

Pour lutter contre ces carences, une solution pourrait être de réutiliser les déchets organiques. Explications.

La « faim cachée », des carences aux conséquences graves

Dans de nombreuses zones rurales, en particulier en Afrique subsaharienne, les mères et leurs enfants souffrent fréquemment de carences en micronutriments essentiels, tels que la vitamine A, le fer et le zinc, qui sont vitaux pour une santé optimale. Ces carences sont souvent liées à des régimes alimentaires dominés par les céréales, peu diversifiés, pauvres en fruits, légumes et protéines animales.

Elles peuvent avoir de graves conséquences sur la santé. La vitamine A, par exemple, est indispensable à la vision. Elle est aussi importante pour le système immunitaire et la santé de la peau. Une carence sévère peut entraîner cécité, infections et décès (mais un excès est également toxique).

La carence en fer est une cause fréquente d’anémie (trop faible teneur d’hémoglobine dans le sang), laquelle se traduit par une pâleur, de la fatigue et un essoufflement. L’anémie peut aggraver les troubles cardiaques. Une carence en fer grave peut aussi mener à des dysfonctionnements cognitifs (« brouillard cérébral », diminution de l’attention, changement d’humeur) et au « pica », une envie irrépressible de manger des produits non comestibles (comme la terre, la glace, des farines, etc.). Des déformations des ongles (ongles en cuillère) et le syndrome des jambes sans repos peuvent aussi en résulter.

Les carences en zinc ont aussi de graves conséquences, car ce métal est le deuxième oligoélément le plus abondant dans notre corps, après le fer. Il est essentiel pour ses effets anti-inflammatoires et antioxydants. Il soutient l’immunité. Une carence en zinc entraîne une perte d’appétit, des troubles cutanés et immunitaires, et peut provoquer des retards de croissance et de développement chez les nouveau-nés et les enfants.

Sur le continent africain, ces carences grèvent non seulement la santé des habitants, mais aussi l’éducation et la productivité. Selon les estimations, la sous-nutrition entraînerait pour le continent une perte de 2 % à 16 % de son PIB.

De nombreux pays concernés

En 2022, le Groupe mondial de recherche sur les carences en micronutriments a publié dans la revue The Lancet les résultats d’une analyse sur les carences en micronutriments chez les enfants d’âge préscolaire et les femmes en âge de procréer dans le monde entier.

Ces travaux ont révélé que plus de la moitié des enfants d’âge préscolaire et des femmes en âge de procréer dans le monde souffrent d’une carence en fer, zinc ou vitamine A.

Ces carences touchent particulièrement l’Afrique subsaharienne, l’Asie du Sud, l’Asie de l’Est et du Pacifique, où vivent la majorité des personnes concernées.

Toutefois, cette étude a aussi montré que, même dans les pays à hauts revenus, comme les États-Unis et le Royaume-Uni, ces carences restent fréquentes chez les jeunes femmes et les enfants.

Comment lutter contre la malnutrition ?

Pour lutter contre la malnutrition, quatre stratégies complémentaires sont possibles.

La première consiste à pallier une carence identifiée en apportant des nutriments spécifiques en plus de l’alimentation sous forme de gélules, d’ampoules… On parle alors de « supplémentation fonctionnelle ». Par exemple, en cas de fatigue liée à une carence en magnésium, ce minéral peut être prescrit sous forme de comprimés, de poudre ou de solution à boire.

Une seconde stratégie consiste à améliorer la qualité nutritionnelle des aliments en micronutriments essentiels en les enrichissant pendant leur transformation industrielle. Cette « fortification des aliments » est mise en œuvre pour produire du sel iodé ou du lait « enrichi en vitamine D ».

La troisième stratégie, appelée diversification alimentaire, encourage le recours à une alimentation équilibrée, grâce à la consommation de produits appartenant à différents groupes alimentaires. Elle est essentielle pour un développement sain, en particulier des jeunes enfants.

Enfin, la quatrième stratégie est la biofortification. Elle se propose d’améliorer la qualité nutritionnelle des aliments directement « dans les champs », grâce à des pratiques agricoles traditionnelles ou au recours aux biotechnologies.

Biofortification agronomique

Contrairement à la fortification, la biofortification se fait pendant la croissance de la plante, et non durant la transformation des produits. Cette biofortification peut être mise en œuvre via trois approches : traditionnelle, génétique ou agronomique.

  • La biofortification traditionnelle utilise des méthodes de sélection végétale pour identifier et croiser des variétés de plantes afin d’améliorer le trait génétique de la teneur en un micronutriment (le zinc d’une variété de riz donnée, par exemple).

  • La biofortification par le génie génétique consiste à introduire artificiellement un gène dans le code génétique d’une culture afin d’obtenir un organisme génétiquement modifié qui va exprimer un micronutriment donné. Un exemple emblématique de cette approche est le riz doré, plus riche en provitamine A que les autres riz.

  • Enfin, la troisième approche de la biofortification, que l’on qualifie d’agronomique, s’appuie sur le potentiel d’une plante à mobiliser et à utiliser les micronutriments qui lui sont apportés afin d’augmenter la teneur en micronutriments de ses parties comestibles. Classiquement, il s’agit d’appliquer des engrais synthétiques (contenant en général un micronutriment) sur les feuilles ou sur le sol.

Cependant, une autre source de micronutriments pourrait provenir de nos déchets organiques, avec le renfort des microorganismes.

Utiliser les déchets pour lutter contre les carences

Les déchets organiques issus des activités agricoles, agro-industrielles et urbaines représentent une ressource précieuse en matière organique et en nutriments essentiels pour la fertilité des sols. Leur valorisation agricole permet de recycler les nutriments et de renforcer une économie circulaire à l’échelle locale.

Ils constituent également une précieuse ressource pour lutter contre la malnutrition. En effet, ils contiennent certains éléments comme le zinc et le cuivre qui sont des micronutriments indispensables à la santé humaine.

En appliquant des pratiques agroécologiques de fertilisation à base de déchets organiques, il est en effet possible d’améliorer la teneur en micronutriments des cultures de base telles que mil, maïs, blé, etc.

Qu’est-ce que l’agroécologie ?

  • Pour rappel, l’agroécologie cherche à transformer en profondeur les systèmes agricoles et alimentaires, en mobilisant la biodiversité et les fonctions naturelles des écosystèmes pour produire durablement, en limitant l’usage d’intrants de synthèse et en tenant compte des aspects sociaux, économiques et politiques.

L’originalité de notre approche réside dans l’intégration de microorganismes efficaces dans le processus de valorisation des déchets organiques.

Les microorganismes locaux à la rescousse

Le consortium de microorganismes d’origine naturelle (bactéries, levures et champignons) que nous utilisons est issu de la litière forestière de zones peu modifiées par les activités humaines, donc biologiquement plus riches et diversifiées que celles qui ont été anthropisées.

Issus de la biodiversité locale, ces microorganismes sont adaptés aux conditions de température, d’humidité et d’aération des sols et restaurent leur microflore tout en étant faciles et économiques à reproduire (ils sont multipliés par fermentation à la ferme).

Leur complémentarité permet de biostimuler de nombreuses fonctions biologiques dans le sol et dans les plantes, renforçant ainsi la santé des sols et stimulant la croissance des plantes.

Notre hypothèse est que ces microorganismes favorisent également la solubilisation du fer et du zinc présents dans les déchets organiques, augmentant ainsi leur disponibilité pour une biofortification naturelle des cultures.

Ils jouent en quelque sorte le rôle de courroie de transmission entre les minéraux apportés par les déchets organiques et l’absorption par les racines de la plante, et ce de différentes façons : minéralisation de la matière organique, solubilisation des éléments traces, facilitation de l’absorption racinaire, stimulation de la croissance racinaire…

Un premier test sur le terrain

Cette approche a été expérimentée au sein du projet OR4FOOD, financé par l’Union africaine et l’Union européenne. En collaboration avec les agriculteurs de la région de Kaffrine, dans le centre du Sénégal, les principes de la biofortification ont été appliqués sur plusieurs cultures d’aliments africains de base, notamment le mil, le niébé ou la patate douce à chair orange.

Les résultats obtenus, en cours de publication, sont très encourageants : les rendements et les concentrations en micronutriments (fer et zinc) des variétés de niébé Thieye et Thissine cultivées de la sorte se sont avérés supérieurs à ceux des variétés traditionnelles.

Lorsque ces variétés naturellement riches en micronutriments reçoivent une combinaison de résidus organiques (litière de volailles) et de microorganismes, les gains en fer obtenus sont de +25 % et ceux en zinc de +33 % par rapport à ces mêmes variétés conduites de façon conventionnelle, avec application d’engrais de synthèse.

Des résultats intéressants ont également été obtenus pour la patate douce à chair orange. Les variétés Apomudem et Kandee ont enregistré des gains de +69 % en fer en ayant reçu une combinaison de litière de volailles et de microorganismes et +39 % en zinc, avec une combinaison de boues d’épuration des eaux usées urbaines et de microorganismes, par rapport aux variétés cultivées de manière conventionnelle.

Ces résultats surpassent aussi les pratiques de biofortification chimique dans un contexte sahélien, ce qui renforce la pertinence des pratiques agroécologiques.

Préserver les nutriments jusqu’à l’assiette

Une fois ces gains obtenus, il est crucial de s’assurer qu’ils seront préservés durant la phase de transformation des aliments, pour garantir qu’ils pourront effectivement bénéficier aux consommateurs.

En effet, la cuisson classique des aliments entraîne, notamment par la chaleur, l’altération du fer et des vitamines. Cela peut réduire leur bioaccessibilité, c’est-à-dire la proportion réellement libérée dans le tube digestif et disponible pour l’absorption par le corps.

Afin de s’assurer leur préservation, et en particulier du gain obtenu lors de la production, OR4FOOD a testé l’optimisation des paramètres de transformation (température, humidité, pression) par la technique de cuisson-extrusion.

Le projet a ainsi montré que les produits obtenus par ce procédé que l’utilisation de la litière de volaille en combinaison avec des microorganismes a augmenté la bioaccessibilité du fer dans le niébé cuit (27 %-29 %) par rapport à la contrepartie non biofortifiée (9 %).

Un point de vigilance auquel nous prêtons une attention particulière est la présence potentielle de contaminants dans les déchets utilisés (pesticides, substances industrielles, métaux, résidus pharmaceutiques, PFAS, microplastiques, microorganismes pathogènes, etc.). Des méthodes d’évaluation de ces risques, qui varient selon l’origine des déchets, sont mises en œuvre ou en cours de développement pour les mesurer.

Le projet OR4FOOD démontre qu’il est possible, sans recours aux organismes génétiquement modifiés, d’améliorer significativement la qualité nutritionnelle des cultures, tout en préservant les rendements et la santé des sols.

Son déploiement pourrait permettre de mieux lutter contre la malnutrition, en complétant avantageusement d’autres stratégies, telles que la diversification alimentaire.


Remerciements :

Ce travail a été soutenu par :

– L’Union africaine (UA) et l’Union européenne (UE), à travers le projet « Organic Residual Products for Biofortified Foods for Africa » (OR4FOOD – numéro de subvention AURG-II-2-110-2018). Nous remercions l’UA et l’UE, nos partenaires de l’Institut sénégalais de recherche agricole (ISRA), de l’Université Cheikh-Anta-Diop (UCAD), de l’lnstitut de technologies alimentaires (ITA) du Sénégal ainsi que ceux d’Addis Ababa University en Éthiopie et de l’Institut de recherche pour le développement (IRD) en France.

– La Banque mondiale à travers le fonds NBS Invest (« Accelerating Nature Based Solutions in Least Developed Countries »), projet ASA « Reflection and knowledge » (contrat 0002010826) pour la valorisation et la diffusion des résultats.

The Conversation

Jean-Michel Médoc a reçu des financements de l’Union Africaine et de l’Union Européenne.

Paula Fernandes a reçu des financements de la Banque Mondiale, fonds NBS Invest (Accelerating Nature Based Solutions in Least Developed Countries), contrat ASA Reflection and Knowledge.

Samuel Legros a reçu des financements de l’Union Africaine et de l’Union Européenne.

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

ref. Malnutrition : utiliser les déchets organiques pour lutter contre la « faim cachée » – https://theconversation.com/malnutrition-utiliser-les-dechets-organiques-pour-lutter-contre-la-faim-cachee-258417

À Gaza, l’illusion humanitaire ne nourrit pas une population affamée

Source: The Conversation – in French – By Pierre Micheletti, Responsable du diplôme «Santé — Solidarité — Précarité» à la Faculté de médecine de Grenoble, Université Grenoble Alpes (UGA)

Alors que la situation humanitaire à Gaza atteint un niveau de gravité sans précédent, les annonces de reprise ou de largage d’aide internationale masquent la réalité d’un dispositif insuffisant et strictement encadré par les autorités israéliennes, pourtant responsables du blocus. Plutôt que de mobiliser les leviers politiques et diplomatiques nécessaires pour lever ce blocus, les interventions se limitent à des actions symboliques, laissant perdurer une crise humanitaire profonde et structurelle.


Sous l’effet des pressions internationales, une timide reprise des approvisionnements humanitaires s’amorce à Gaza.Toutefois, les responsables israéliens, comme c’est le cas depuis 2005, prolongent une fois encore la « stratégie de la perfusion contrôlée ». Les mécanismes qui aboutissent à la crise actuelle sont ainsi connus et dénoncés depuis plus d’un an . Les flux alimentaires vitaux ont été maintenus, à la limite constante de la suffocation ; juste suffisants pour éviter une mortalité massive qui viendrait parachever le drame qui se joue depuis octobre 2023.

Avec une telle mortalité, le risque serait trop grand qu’enfin se dégage un consensus qui pourrait balayer l’incroyable inertie qui prévaut dans la gouvernance des relations internationales. Les autorités israéliennes le savent.

Les livraisons cosmétiques annoncées ne sont pourtant en rien résolutives du drame que connaît la population civile de ce territoire depuis plus de 18 mois maintenant.




À lire aussi :
Malnutrition à Gaza : son impact sur les 1 000 premiers jours de vie des bébés


Les largages alimentaires : une aide dérisoire face à une population dévorée par la famine

Elles empruntent des modalités qui, dans le sillage du calamiteux dispositif de la Fondation Humanitaire pour Gaza, continuent de déroger à toute préoccupation d’efficacité et de respect des principes humanitaires à l’égard d’une population civile qui vit dans un territoire occupé par une puissance extérieure.
Car les mesures annoncées contreviennent à la mise en œuvre effective d’une sécurité alimentaire qui repose sur 4 piliers .

D’abord la disponibilité des denrées. C’est sur ce seul axe que portent l’accroissement annoncé des volumes d’aide délivrée. Avec une volumétrie qui soulève cependant des doutes : 100 camions annoncés là où avant le conflit massif plus de 500 étaient mobilisés chaque jour. L’ONU estime à 62 000 tonnes par mois la nécessaire disponibilité de denrées alimentaires.

Le deuxième pilier concerne l’accessibilité effective de la population civile aux denrées ayant franchi la frontière. Une accessibilité qui porte sur la capacité à se déplacer pour accéder à la nourriture, – accessibilité géographique – particulièrement cruciale pour les malades, les blessés et les personnes âgés, des dizaines de milliers de personnes en l’occurrence ; l’exposition à la violence militaire met en jeu l’accessibilité sécuritaire ; et selon les circuits de répartition ensuite empruntés par les aliments, des coûts qui peuvent être prohibitifs si livrés à la dérégulation d’un marché noir favorisé par l’absence d’encadrement sur le terrain – accessibilité financière -.

Le 3ème pilier repose sur la capacité des populations à utiliser effectivement les produits entrés sur le territoire. C’est-à-dire de pouvoir disposer des ustensiles de cuisine, du combustible et des autres ingrédients dont l’eau qui permettent la préparation des aliments qui nécessitent une cuisson.

Les blessés graves ou inconscients nécessitant par ailleurs une nutrition parentérale spécialisée et contrôlée par des professionnels de santé dont la mortalité a également été massive depuis octobre 2023. Et enfin, quatrième composante de la sécurité alimentaire : la stabilité dans le temps des 3 piliers précédents et non, comme cela est le cas depuis 18 mois, des livraisons erratiques dans le temps et dans l’espace.

La sous-nutrition aigue qui peut conduire à la mort, résulte ainsi d’un équilibre entre les apports qui construisent la sécurité alimentaire et les excès de pertes, le plus souvent liées à des diarrhées aigües très fréquentes là où la qualité de l’eau de boisson ne peut être garantie. Tel est le cas pour la population de Gaza, dont la densité était avant le conflit l’une des plus élevées au monde .

Sous le siège israélien, les Gazaouis abandonnés à une famine dévastatrice

La population, dont plus de 80% est poussée à une errance perpétuelle , est aujourd’hui concentrée sur de faibles surfaces territoriales, vivant au milieu des déjections humaines et animales, sans non-plus les moyens d’une hygiène corporelle minimale, et alors-même que la sous-alimentation chronique expose en particulier les enfants à une plus grande mortalité par déficit immunitaire.

Ce sont toutes ces composantes vitales que ne peut résoudre la seule augmentation modeste en volume qui est annoncée par les autorités israéliennes. Cette décision relève du marketing humanitaire si elle reste isolée.

Cette punition collective n’a que trop duré pour les 2 millions de personnes qui errent sur un territoire de 40km de long sur 10 de large. Malgré les récentes annonces, la vigilance reste de mise pour que les approvisionnements dérisoires – largement médiatisés – ne soient pas érigés en solution généreuse et durable…
Une mobilisation inédite de grandes ONG internationales ne cesse d’interpeller sur la situation catastrophique que vivent la population comme les équipes d’acteurs humanitaires .

Un véritable cessez-le-feu doit être instauré, et des décisions politiques prises pour qu’enfin se dégagent les perspectives d’une paix durable. La prochaine Assemblée générale des Nations-Unies en septembre 2025 à New York constitue une opportunité de prendre des décisions pour « le jour d’après » la période de conflit. Des initiatives politiques se multiplient, en particulier autour de la reconnaissance de l’Etat de Palestine par un nombre croissant de pays.

The Conversation

Pierre Micheletti est membre :

Président d’honneur d’Action Contre la Faim
Ancien président de Médecins du Monde
Administrateur de SOS Méditerranée
Membre de la Commission Nationale Consultative des Droits de l’Homme

ref. À Gaza, l’illusion humanitaire ne nourrit pas une population affamée – https://theconversation.com/a-gaza-lillusion-humanitaire-ne-nourrit-pas-une-population-affamee-262461

Love in the age of WhatsApp – a philosopher explains how technology reduces the power of a relationship

Source: The Conversation – UK – By Tony Milligan, Research Fellow in the Philosophy of Ethics, King’s College London

antoniodiaz/Shutterstock

A sense of distance has always been part of romantic love. The experience of wanting to be with another person often requires separation, if only in the form of days apart for work and travel. Matters become more complicated, however, when that distance is mediated by technology – by dating app swipes, messaging on WhatsApp and FaceTime.

For myself, as a philosopher of love, there is no good reason to say that loving relationships of a mostly remote nature cannot endure – or that physical separation inevitably and eventually destroys love. Much of society’s collective understanding of love suggests this is simply not true. Longing for another human can continue at a distance, even if we want that distance to end.

That said, one of the most familiar uncertainties about romantic love is the fear that it is a drama played out within the self, and that the other person does not care in the same way. When technology mediates contact, this can strengthen familiar forms of scepticism about love – for example, about whether or not the other person is really who they seem to be. We want sincerity and depth of feeling. Not just a pleasing response.


Dating today can feel like a mix of endless swipes, red flags and shifting expectations. From decoding mixed signals to balancing independence with intimacy, relationships in your 20s and 30s come with unique challenges. Love IRL is the latest series from Quarter Life that explores it all.

These research-backed articles break down the complexities of modern love to help you build meaningful connections, no matter your relationship status.


If I am apart from my wife Suzanne for any length of time, I want our conversations over FaceTime and WhatsApp to be quite different from the interactions that might be possible with an AI girlfriend. I still want a real, tangible person at the other end of the technology, with whom I could share an embrace if only we were together.

In other words, our technologically mediated interactions do not stand alone – they are part of a life which is largely spent together. Location matters, and this is one of the aspects of love that accounts of the philosophy of love are generally bad at understanding (with the possible exception of some of the work on love by Japanese philosophers such as Nishida and Watsuji).

Two women holding hands and smiling
We expect our relationships to feel different in real life than they do digitally.
Anna Selle/Unsplash

I do not mention shared places at all in my own book on love. Yet they are central to being a couple. People do not typically just want to meet in some random location. We want to be together in a determinate series of places, including our homes. Too much technological mediation can undermine this sense of being somewhere together physically. Being together online is not the same.

Love and its limits

My thought then is not that technologically mediated love cannot endure, but that it becomes something second-rate if there is too much mediation and not enough actual being together in a shared physical place.

This is an unpopular thought for two reasons. First, it involves saying that Plato and a long line of western philosophers have been right: some kinds of love really are better than others. “Better” in the simple and obvious sense that they are geared towards meeting our needs, smoothing out the bad parts of life, and making sure there are also enough high points.

Scientists can see this at a neurophysiological level. Some kinds of love activate the brain’s feel-good attachment and reward networks more than others. Romantic love and parental love activate more of these networks than love for pets, though the latter does trigger a genuine response.

Second, it involves saying that love is not infinitely plastic – it cannot be just anything we want it to be. Romantic love has a social history reaching back at least a couple of thousand years and perhaps a good deal longer. Our few surviving remnants of prehistoric tales deal with loss and longing, played out across the night sky.

Yet love has an even larger history which is shared with other social animals. It is a mark of our creatureliness, our physicality as a special kind of animal. We are not ghosts flitting across the glaciers, embracing only in cyberspace.

Woman sad holding up a piece of paper that says 'I miss you' so it can be seen through her webcam.
The fact we are human sets limits on the kinds of love that can work well.
Drazen Zigic/shutterstock

Our heavily constructed romantic ideas about what we can mean to one another still depend upon a solid evolutionary foundation of wanting to be somewhere familiar with a special someone – and grieving when this is no longer possible. Dogs do it, chimps do it, and so do we.

And so, if anyone wants to say that a largely remote and mediated relationship can be just as good as being together in shared places, or that a romantic relationship with a holographic anime character can be just as good as a romantic relationship with a real person, then my response is “not for beings like us”.

The fact we are human sets limits to the kinds of love that can work well. As I explore in my research, love is not a democracy. All loves are not equal. There are limits to the ways in which technologies can mediate (or even take the place of) romantic relationships of the most fulfilling sorts.

None of which will stop Suzanne from texting me, or me texting Suzanne, with a suitable range of emojis. And none of which will stop us from video-meeting at every opportunity when we are separated by an ocean or two.

But as we do these things, the promise is always there of a return to the places where we exist physically together. Using technologies when separated by great distances is not a substitute for sharing these places. It is a way of saying that we are coming home.


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The Conversation

Tony Milligan 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. Love in the age of WhatsApp – a philosopher explains how technology reduces the power of a relationship – https://theconversation.com/love-in-the-age-of-whatsapp-a-philosopher-explains-how-technology-reduces-the-power-of-a-relationship-254342

Young carers face higher risks of depression, anxiety and lost futures – and most receive no support

Source: The Conversation – UK – By Aoife Bowman Grangel, PhD Candidate in Health Psychology, University of Limerick

Around 12% of teens are unpaid carers and it’s harming their prospects. Daisy Daisy/Shutterstock

In developed countries, around 12% of young people provide regular, unpaid care for a family member. It’s work that’s essential, often invisible – and potentially devastating to their mental health. As more families rely on these young carers, many are left without legal protections, recognition, or the support they urgently need.

Across Europe, informal carers now provide up to 80% of all long-term care. This figure is rising sharply due to ageing populations, an increase in chronic illness, and advances in medical technology. Between 2000 and 2050, the demand for unpaid care is expected to grow by 50% in Europe alone, with similar trends emerging in the US and Australia.

As adult carers struggle to meet rising demand, children, teenagers and young adults are stepping into the breach. These young carers often take on domestic, emotional, practical and personal care tasks that would challenge any adult. While some report growing resilience, maturity and empathy, the long-term toll on education, mental health and physical wellbeing is increasingly hard to ignore.

Lost opportunities, lasting consequences

Globally, young carers face significant restrictions on their education and career prospects. In both the UK and Germany, research shows that young adult carers are less likely to complete university, less likely to secure employment and more likely to experience long-term unemployment than their peers. These disadvantages aren’t just financial – they’re linked to increased rates of depression and anxiety later in life.

The social cost is high, too. Young carers are more likely to face bullying, isolation and limited opportunities for friendship or leisure. Chronic illness in the household can increase stress, leading to economic hardship, family breakdown and domestic conflict. Mental health is caught in the crossfire: many young carers experience psychological distress, depression and even self-harm.

Along with colleagues, I published a study that underscored the urgency of this issue. Our research showed that young carers in high-income countries are significantly more likely than their peers to experience poor mental health, including anxiety, depression and severe emotional distress.

Not all care is equal – and neither are its effects. The intensity, type and duration of caregiving matter greatly. Young carers who provide personal care, dedicate more hours each week, or have cared for a longer period are at the greatest risk of mental health difficulties.

Girls and young women are particularly vulnerable. They are overrepresented among young carers and are more likely to take on intensive or prolonged responsibilities. These disparities don’t end in childhood. As young adults, female carers tend to experience lower educational attainment and less workforce participation than their male counterparts – disadvantages that have ripple effects on their long-term mental and economic wellbeing.

Invisible and unsupported

Despite their growing numbers, young carers are often invisible to schools, healthcare providers and policymakers. Most European countries provide no formal recognition, rights or protections. Even though the European parliament addressed the issue in 2018 and 2022, young carers remain absent from key EU frameworks.

The UK is a notable exception, with specific rights and national interventions for young carers. But gaps remain. A 2016 report found that nearly one in three young carers identified by local authorities received no support at all.

In the US, the situation is worse: a lack of national data means young carers are missing entirely from most political conversations and care agendas.

Yet support makes a difference. Studies show that recognition and perceived support, whether from teachers, friends, professionals or government policies, can protect young carers’ mental health and improve their long-term outcomes. Support can take many forms: respite care, school accommodations, financial assistance, mentoring, or even a simple acknowledgement that their role matters.

Without intervention, the personal and societal costs are substantial: deteriorating mental health, lost educational and career opportunities and increased economic dependency in adulthood.

If we fail to support young carers, we fail an entire generation of quiet caregivers – and risk undermining the sustainability of our health and care systems for decades to come.


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Aoife Bowman Grangel receives funding from the Irish Research Council.

ref. Young carers face higher risks of depression, anxiety and lost futures – and most receive no support – https://theconversation.com/young-carers-face-higher-risks-of-depression-anxiety-and-lost-futures-and-most-receive-no-support-260654

Technology could open up new ways to track prisoners

Source: The Conversation – UK – By Amin Al-Habaibeh, Professor of Intelligent Engineering Systems, Nottingham Trent University

Ankle bracelet monitoring technology could be taken a step further. Stock City/Shutterstock

Technology firms have apparently suggested placing tracking devices or a microchip under the skin of convicted criminals to monitor them in prison or when they come out, according to a recent report in the Guardian. Though the idea raises questions about human rights, the technology is certainly developing that could make such an initiative possible.

Electronic ankle bracelets are already widely used forms of this technology. They normally use a radio frequency connected to a base station, similar to your home WiFi, to ensure the device is within a specific range in or around the house. Others use GPS to monitor the location of the person. Such devices require regular charging, however.

Anyone can use commercial technology such as AirTags from Apple or the Samsung SmartTag that allow people or items to be tracked. The monitoring technology is integrated with mobile phone applications. This includes the use of other people’s phones in an encrypted network of communications.

In the UK, there are different types of technologies available that utilise GPS and other wireless systems to monitor individuals who are subject to movement restrictions because of a court order.

The technology was first introduced in the UK in 1999 and it is normally used as an alternative to custody or imprisonment. According to a UK government website, there are three types of tagging: curfew tags, location tags and alcohol tags. A curfew tag checks the location of the tagged person from a base unit (such as their home) within a specific time period.

If the base unit cannot communicate with the tagged person, it will send an alert to the related monitoring centre. Location tags have more flexibility as they monitor the location and provide information about areas that the person should not access or should visit such as rehabilitation appointments.

The third most common type are alcohol tags where the alcohol level is measured from the sweat of a person. The aim is to reduce violence or crimes related to intoxication of alcohol. In 2022, the UK government reported that approximately 97% of offenders’ with these tags stayed off alcohol.

In general, greater use of electronic tagging could lead to more prisoners being released early and so help reduce the pressure on prison facilities. This could have other social benefits such as avoiding any disruption of employment or family commitments.

However, limitations such as problems with the device signal or false alarms for breaching court orders have been observed in several studies. A 2019, study by the Scottish Government highlighted some of the strengths and weaknesses of these technologies. However, with the continuous development of monitoring technologies, such limitations are expected to be addressed with more effective applications in the future.

Hand with a section shown in X-ray with bones and a microchip visible
Chips could be implanted under the skin.
Alexa Mat/Shutterstock

Technology that involves implanting tags under the skin has been explored in in the past for applications such as proof of identity, contactless payment systems and the opening of secure doors.

One type of implant uses a radio frequency identification (RFID) tag and is about the size of a grain of rice. In theory, similar technology could be used with a base unit or distributed monitoring network to develop a tracking system to locate a person.

RFID tagging is used routinely in supermarkets to prevent theft. The tags are often attached to expensive items to prevent them from being taken from the store without payment.

However, human rights campaigners have called the proposals from the tech companies for microchip trackers and other devices “dystopian”. Forcing people to undergo invasive surgery to enable technology firms to gather what could become highly sensitive and personal data about them takes punishment a step beyond the temporary restriction of people’s freedom of movement.

Electronic monitoring technologies, with AI support, are advancing at rapid pace. In the future and globally, the technology is expected to play a vital role in enhancing public safety, supporting rehabilitation and minimising the cost to public funding. But questions also have to be answered about what role we want this kind of technology to play in our society.

The Conversation

Amin Al-Habaibeh receives funding from Innovate UK, The British Council, The Royal academy of Engineering, EPSRC, AHRC, and the European Commission.

ref. Technology could open up new ways to track prisoners – https://theconversation.com/technology-could-open-up-new-ways-to-track-prisoners-261625

Enjoyed together, Red Dwarf and Jane Austen offer a lesson in immersive world building

Source: The Conversation – UK – By Emma Newport, Associate Professor in English Literature, University of Sussex

This year marks the 250th anniversary of Jane Austen’s birth. An Austen enthusiast might attend the birthday ball at the Alton Assembly Rooms in Hampshire or take an Austen-themed walking tour. They might dance at the Pump Rooms in Bath, a city with strong Austen connections, or in Utah, which has none.

These kinds of immersive events tend to surge in times of social and economic fragility. In part, this may be due to a particular form of nostalgia that psychologists have noted helps to mitigate loneliness and forge social connection.

During the pandemic, the Netflix show Bridgerton marked a revival of Austen-adjacent worlds. Fandoms that invite participation function like virtual realities, offering the kind of immersion we might expect from a headset and game console. But is this merely escapism, or do such immersible worlds offer ways of experiencing the present differently and more reflectively?

My first encounter with the immersive potential of Austen came through science fiction. In series seven of Red Dwarf (1997), characters are dispatched into the fictional Pride and Prejudice Land. It’s part of the newly arrived crew member Kristine Kochanski’s (Chloë Annett) favourite game, Jane Austen World – a virtual reality simulation she uses to civilise the other characters.


This article is part of a series commemorating the 250th anniversary of Jane Austen’s birth. Despite having published only six books, she is one of the best-known authors in history. These articles explore the legacy and life of this incredible writer.


Kryten, the service droid, breaks into this Regency idyll aboard a second world war tank and detonates a tea party, roaring “Dinner is served!” The absurdity left a strong impression on my younger self about Austen’s perceived delicacy, and the chaotic energies that surround her cultural afterlives.

Written by Robert Llewellyn (who also plays Kryten), the episode leans hard into domestic satire. Kryten’s female-coded role as cook, cleaner, carer and emotional manager puts him at odds with the interloper Kochanski, a middle-class, degree-educated white woman determined to instil gentility into the racially diverse group who occupy the lowest rung of the ship’s hierarchy.

Kryten’s unvoiced rage culminates in literal explosion, his head detonating when his labour goes unacknowledged. The episode becomes unexpectedly dense: an examination of gender, class, race and post-human servitude. Beneath the explosive humour is a serious comment on immersion and gendered emotional labour.

Austen’s world of tea tables and letter writing, here rendered virtual, is shown to be both seductive and suffocating. It is a place where emotion is both cultivated and dangerously suppressed.

Austen’s claustrophobic worlds

Returning to Austen’s writing at university, I carried my own Dwarf-inspired desire to explode Austen – and to join Mark Twain in a desire to “dig her up and beat her over the skull with her own shin-bone” when I had to read Pride and Prejudice (1813).

I mistakenly believed Austen’s novels offered an obsessive focus on narrow domesticity while ignoring war, revolution, poverty and the illiberal qualities of a supposedly enlightened age. However, in later life I came to realise that, like the confines of a mining ship in deep space, what Austen describes is less small than it is dense and claustrophobic.

A drawing of Jane Austen by her sister, Cassandra.
A drawing of Jane Austen by her sister, Cassandra.
NPG

Austen’s writing is sharply attentive to the relationship between imaginative freedom and physical constraint, especially for women. Her characters frequently reflect on travel and distance. In Persuasion (1817), Anne Elliot remarks that men “live in the world” while women like herself “live in it only by hearing of it”. In Mansfield Park
(1814), Edmund Bertram jokes that his cousin Fanny Price will “be taking a trip into China” through her reading.

His remark is inflected by Austen including reference to British author Samuel Johnson and his collection The Idler (1760), which Edmund lists among the books he imagines Fanny to be transported by. In an essay from The Idler, Johnson dismisses travel writing as disappointing, failing in immersing the reader for it so often only describes “the face of the country”.

Edmund and Fanny’s conversation takes place in the country house’s East Room, which Austen researchers have described as the most prominent metaphor for Fanny’s “spiritual distance” from the rest of the household. The room is filled with castoffs: faded embroidery, unwanted books, bad portraits. Fanny, too, is a penniless castoff, taken in by wealthier relations but frequently overlooked.

When her uncle sends her back to her lower-class family for refusing a lucrative match, Fanny is punished for her autonomy. She cannot leave Mansfield Park at will, and her imagined departures, whether into books, ideas or “China” – where she might enter a form of narrative virtual reality – offer no protection from real-life threats. Fanny’s reading in the East Room is abruptly curtailed by Edmund’s needs and the encroaching domestic chaos of an amateur theatrical production.

Yet this constraint is part of Austen’s point. The grand estate of Mansfield Park is funded by a shadowy West Indian plantation and enslaved labour, an economic foundation that goes unspoken and unseen. Those who travel there do so off the page.

When Fanny raises the question of the plantation’s ethics, she is met with silence. Who and what is not seen – Fanny, the plantation and its workers, the real costs of luxury – become as significant as what is. Fanny’s room, stripped of wealth, stands in quiet opposition to the brutal source of Mansfield Park’s comforts.

Immersible worlds – whether a Regency ball in Bath, a role in a household play, or a journey into “China” – can be a form of forgetting as much as imagining. The cast at Mansfield throw themselves into Elizabeth Inchbald’s Lovers’ Vows (1798), a sexually suggestive play, with little reflection on how their roles might influence or be influenced by their desires. Fanny, unwilling to participate, sees these risks more clearly, as she does with the larger social problems to which her cousins remain wilfully unseeing.

In Austen’s novels, the immersive imagination is double-edged: it contains the risk of abstraction and of losing touch with the present, even as it offers solace and self-making. What Austen reminds us, then, is to interrogate our relationship with immersible worlds.

As technology brings us ever closer to the virtual realities experienced by the boys from the Dwarf – and as our lived reality is growing more precarious, impoverished and violent – immersible worlds await the careworn. Yet we must beware simply rehearsing the silences which Austen so carefully wrote around.


This article features references to books that have been included for editorial reasons, and may contain links to bookshop.org. If you click on one of the links and go on to buy something from bookshop.org The Conversation UK may earn a commission.

The Conversation

Emma Newport 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. Enjoyed together, Red Dwarf and Jane Austen offer a lesson in immersive world building – https://theconversation.com/enjoyed-together-red-dwarf-and-jane-austen-offer-a-lesson-in-immersive-world-building-259612

The Victorian sportswomen who had to fight misogynistic abuse, just like the Lionesses

Source: The Conversation – UK – By Tarini Bhamburkar, Research Affiliate, University of Bristol

Much of England has been celebrating the Lionesses’ historic win at the Uefa European Women’s Championship – the first time a senior England football team has won a major championship abroad and retained a major trophy. However, not everyone was pleased.

Former footballer and manager Joey Barton took to X to express his underwhelm, writing: “Well done to the Lioness winning the Nonsense Pottery Trophy. Those penalties were borderline embarrassing again. Don’t ever ask for equal pay again. Youse are miles off it. 🐕💨”

Barton has faced a backlash for his outdated response to the historic win, with many pointing out that the Lionesses have won more cups for England than Barton – who has won zero with the senior team, having played only 17 minutes as a substitute for them.

Sadly, Barton is just one in a long line of men who have attacked sportswomen, while refusing to recognise that women have been excelling at sport for over a century. At the same time, there is a long line of women players and fans who have repeatedly called out such misogyny.


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I have spent the last year-and-a-half digging into newspaper archives where the stories of some of these women can be found. In their own words, these sportswomen and their fans detail their experiences as pioneers – and the attacks they faced along the way.

The earliest accounts of women engaging in sport in Britain show them playing tennis or croquet, or being adept at horse riding, in the 19th century. These were seen as permissible recreational activities for the “fairer sex”, but only if the practice of them remained noncompetitive.

But in the late Victorian age this changed, as women started playing many more sports – in some cases professionally. Women’s participation in athletics and competitive sports such as cricket was furiously debated – predominantly by men, who saw it as defying traditional gender roles. At the time, a woman wanting to be a professional sportswoman was widely seen as questionable and ungraceful.

The front page of Women's Penny Paper with the interview with Daisy Stanley.
The front page of Women’s Penny Paper with the interview with Daisy Stanley.
British Library, CC BY-NC-ND

There were, however, many female sports people and fans who were arguing against such ideas. I was particularly struck by one interview from 1890 with the remarkable Miss Daisy Stanley, captain of the Blue Eleven women’s cricket team.

The Original English Lady Cricketers are one of the earliest examples of paid, professional sportswomen who toured nationally between 1890 and 1892. They comprised 30 women divided into two teams: the Red XI and Blue XI.

Stanley’s interview was published on the front page of the weekly woman-edited newspaper, Women’s Penny Paper. As a progressive women’s newspaper, it was keen to profile a professional female player and inspire its women readers.

Throughout the interview, the unnamed lady journalist refers to her interviewee as “Captain Stanley” (rarely using any other term for her), asking significant questions about herself, her team and her ambitions. The article notes the enthusiasm for these women cricketers after their first public match in Liverpool against a local men’s side, where “visitors assembled in thousands”.

But the journalist laments the unserious treatment of the players at the hands of the “gentlemen” players, noting: “Whenever the game has been between ladies and gentlemen, the latter have … assumed broomsticks and treated their adversaries as weaker vessels.”

You can trace the thread from the attitudes to this pioneering cricket match in 1890 right up to Barton’s comments about the Lionesses in 2025.

Undaunted, the “tall and well-built” Captain Stanley, who looked “capable of much execution in the way of play”, rose through these afflictions. Before becoming a professional cricket player and playing regularly, she had considered the game impossible for girls to excel in – a view she reveals in the interview to have been “materially altered” by her experience of playing the game professionally.

Stanley is full of praise for ladies’ participation in sports, deeming that “there is not a more healthy … or beneficial game than cricket for our sex”.

In the wider society of the time, though, the possibilities – and benefits – of sports for women were being puzzled out socially and publicly through articles in periodicals. An article titled “Athletics for Ladies” in Cassell’s Family Magazine in 1896 lauded the benefits of women’s cautious “physical or muscular progress”, for example, but saw “football as a man’s game”.

The idea of women playing sports, let alone playing competitively, was both mocked and rebuked by swathes of the British media and public. But despite the ubiquitous pushback around them, women like Captain Stanley remained undeterred. In the interview in the Women’s Penny Paper, she mentions her thorough knowledge of the game, gives a shout-out to worthy team members and their skills, and celebrates her love of the sport.

Reflecting on having watched the paid professional Victorian women playing their cricket match so well, the impressed interviewer notes something that we would do well to remember today: “That here, as elsewhere, when women really take a thing in hand, they can and will carry it out thoroughly.”

The Lionesses have certainly done that, and we have the facts to back it up. After all, Chloe Kelly’s winning penalty kick on Sunday was reportedly faster than any shots on goal by the men this Premier League season. Try arguing with that.


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Tarini Bhamburkar has received funding from the Royal Historical Society.

ref. The Victorian sportswomen who had to fight misogynistic abuse, just like the Lionesses – https://theconversation.com/the-victorian-sportswomen-who-had-to-fight-misogynistic-abuse-just-like-the-lionesses-261798

The Soviet Union’s secret tsunami

Source: The Conversation – UK – By Patrick David Sharrocks, PhD Candidate in Tsunami Geohazards, University of Leeds

On July 30, one of the largest earthquakes ever recorded struck off the Kamchatka peninsula, in Russia’s far east. Within minutes, tsunami warnings were issued in Russia, much of Asia and across the Pacific in Hawaii, New Zealand and California.

But this wasn’t the first time a huge tsunami had hit Kamchatka. In 1952, an even more powerful earthquake hit the same fault line – but it was kept hidden from the world.

Kamchatka is no stranger to seismic activity, with a large earthquake occurring as recently as 2020 (the fourth most powerful anywhere in the world that year). However, only the biggest earthquakes can create large destructive tsunamis and cause Pacific-wide warnings like those experienced on Wednesday.

On a plate boundary, where two pieces of the Earth’s crust meet, such large earthquakes often occur on consistent timescales known as “seismic cycles”. In some areas, these cycles are long: on the Cascadia boundary off the Pacific coast of North America, for instance, the last major tsunami-generating earthquake was in 1700.

However, the plates move much faster near Kamchatka (around 8 centimetres a year) and the the cycle is much shorter. Large tsunamis were generated from earthquakes in 1737, 1841, 1952 – and now 2025 is a continuation of this cycle.

Just after midday on November 5 1952, tsunami waves up to 8 foot (2.4 metres) hit Hawaii. This was an early test for the Pacific Tsunami Warning Center, which had recently been established on the islands in response to a 1946 tsunami following an earthquake in Alaska.

Earlier that day, seismologists across the world had detected signals from an earthquake pinpointed to the northwest Pacific around Kamchatka. When the wave hit Hawaii, scientists there quickly used the exact time of the wave and the known speed of tsunamis (in deep water, these are similar to a jet plane) to deduce it must have been created by that giant earthquake in the northwest Pacific. But from Kamchatka itself, there was silence.

There were no reports of an earthquake or tsunami in the Soviet press. Not a word was written in state newspaper Pravda, which instead focused on preparations for the Great October Revolution anniversary two days later.

Days and months passed without any recognition of the tsunami and earthquake. Even an interview with a Russian volcanologist, Alexander Evgenievich Svyatlovsky, was stored as a “state secret”, despite him merely explaining how the tsunami had originated.

Such secrecy was common at the height of the cold war, with Chernobyl and other disasters often being underreported by the Soviet authorities. It was only after the release of state archives in the early 2000s that the full picture could be told.

The devastation at Severo-Kurilsk

The isolated fishing town of Severo-Kurilsk lies on an island just south of the Kamchatka peninsula. According to state archives, 6,000 people lived there in 1952, spread thinly across the coastline.

On the morning of November 5, inhabitants were woken by a major earthquake, the strongest anyone there had ever felt. Around 45 minutes later a wave arrived, slowing and steepening as it reached the shore. Soldiers on lookout were able to warn people of the danger, and many fled to high ground.

But tsunamis are wave trains with a series of peaks and troughs. They act much like waves you’d experience on a beach – except that these waves stretch thousands of metres into the ocean, hitting the shore not every few seconds but with tens of minutes between each one.

Minutes after some residents had returned to their homes, a second, larger wave struck. It rose some 12 metres high – as tall as a three-storey building – and hit the town from behind. A third wave soon followed, washing away much of the town that remained.

In all, the tsunami caused 2,336 deaths out of a population of 6,000. The survivors never shared the details for fear of reprisals, and the story remained a state secret.

Today, Severo-Kurilsk sits 20 metres above sea level, rebuilt and fortified. Videos from the 2025 tsunami show flooding at the port, but there are no reported fatalities – testament to modern warning systems and urban planning.

One problem remains: the repositioning of the town has placed it in the path of deadly mudflows from the nearby volcano Ebeko (only 7km away). For Severo-Kurilsk, tsunamis represent only one of many threats in this corner of the Pacific.


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Patrick David Sharrocks receives funding from the Natural Environment Research Council, grant number NE/S007458/1.

ref. The Soviet Union’s secret tsunami – https://theconversation.com/the-soviet-unions-secret-tsunami-262452

​The contagion scale: which diseases spread fastest?

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

Gelefin/Shutterstock.com

When the COVID pandemic hit, many people turned to the eerily prescient film Contagion (2011) for answers – or at least for catharsis. Suddenly, its hypothetical plot felt all too real. Applauded for its scientific accuracy, the film offered more than suspense – it offered lessons.

One scene in particular stands out. Kate Winslet’s character delivers a concise lesson on the infectious power of various pathogens – explaining how they can be spread from our hands to the many objects we encounter each day – “door knobs, water fountains, elevator buttons and each other”. These everyday objects, known as fomites, can become silent vehicles for infection.

She also considered how each infection is given a value called R0 (or R-nought) based on how many other people are likely to become infected from another. So, for an R0 of two, each infected patient will spread the disease to two others. Who will collectively then give it to four more. And so a breakout unfolds.

The R0 measure indicates how an infection will spread in a population. If it’s greater than one (as seen above), the outcome is disease spread. An R0 of one means the level of people being infected will remain stable, and if it’s less than one, the disease will often die out with time.

Circulating infections spread through a variety of routes and differ widely in how contagious they are. Some are transmitted via droplets or aerosols – such as those released through coughing or sneezing – while others spread through blood, insects (like ticks and mosquitoes), or contaminated food and water.

But if we step back to think about how we can protect ourselves from developing an infectious disease, one important lesson is in understanding how they spread. And as we’ll see, it’s also a lesson in protecting others, not just ourselves. Here is a rundown of some of the most and least infectious diseases on the planet.

In first place for most contagious is measles.

Measles has made a resurgence globally in recent years, including in high-income countries like the UK and US. While several factors contribute to this trend, the primary cause is a decline in childhood vaccination rates. This drop has been driven by disruptions such as the COVID pandemic and global conflict, as well as the spread of misinformation about vaccine safety.

The R0 number for measles is between 12 and 18. If you do the maths, two cycles of transmission from that first infected person could lead to 342 people catching the illness. That’s a staggering number from just one patient – but luckily, the protective power of vaccination helps reduce the actual spread by lowering the number of people susceptible to infection.

Measles is extraordinarily virulent, spreading through tiny airborne particles released during coughing or sneezing. It doesn’t even require direct contact. It’s so infectious that an unvaccinated person can catch the virus just by entering a room where an infected person was present two hours earlier.

People can also be infectious and spread the virus before they develop symptoms or have any reason to isolate.

Other infectious diseases with high R0 values include pertussis, or whooping cough (12 to 17), chickenpox (ten to 12), and COVID, which varies by subtype but generally falls between eight and 12. While many patients recover fully from these conditions, they can still lead to serious complications, including pneumonia, seizures, meningitis, blindness, and, in some cases, death.

Low spread, high stakes

At the other end of the spectrum, a lower infectivity rate doesn’t mean a disease is any less dangerous.

Take tuberculosis (TB), for example, which has an R0 ranging from less than one up to four. This range varies depending on local factors like living conditions and the quality of available healthcare.

Caused by the bacterium] Mycobacterium tuberculosis, TB is also airborne but spreads more slowly, usually requiring prolonged close contact with someone with the active disease. Outbreaks tend to occur among people who share living spaces – such as families, households, and in shelters or prisons.

The real danger with TB lies in how difficult it is to treat. Once established, it requires a combination of four antibiotics taken over a minimum of six months. Standard antibiotics like penicillin are ineffective, and the infection can spread beyond the lungs to other parts of the body, including the brain, bones, liver and joints.

What’s more, cases of drug-resistant TB are on the rise, where the bacteria no longer respond to one or more of the antibiotics used in treatment.

Other diseases with lower infectivity include Ebola – which is highly fatal but spreads through close physical contact with bodily fluids. Its R0 ranges from 1.5 to 2.5.

Diseases with the lowest R0 values – below one – include Middle East respiratory syndrome (Mers), bird flu and leprosy. While these infections are less contagious, their severity and potential complications should not be underestimated.

The threat posed by any infectious disease depends not only on how it affects the body, but also on how easily it spreads. Preventative measures like immunisation play a vital role – not just in protecting people, but also in limiting transmission to those who cannot receive some vaccinations – such as infants, pregnant women and people with severe allergies or weakened immune systems. These individuals are also more vulnerable to infection in general.

This is where herd immunity becomes essential. By achieving widespread immunity within the population, we help protect people who are most susceptible.


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

ref. ​The contagion scale: which diseases spread fastest? – https://theconversation.com/the-contagion-scale-which-diseases-spread-fastest-261975

Why the US is letting China win on energy innovation

Source: The Conversation – UK – By Stephen Lezak, Programme Manager at the Smith School of Enterprise and the Environment, University of Oxford

The Heyuan Queyashan wind farm near the Chinese city of Heyuan, Guangdong province. maple90 / Shutterstock

During the cold war, the US and Soviet Union were locked in a desperate race to develop cutting‑edge technologies like long-range missiles and satellites. Fast forward to today and the frontiers of global technology have pivoted to AI and next‑generation energy.

In one domain, AI, the US has far outpaced any other nation – though China looks to be closing the gap. In the other, energy, it has just tied its shoelaces together. The reason isn’t technology, economics or, despite the government’s official line, even national security. Rather, it is politics.

Since returning to the White House in January, Donald Trump has handed out huge wins to the coal and oil and gas industries. This is no great surprise. Trump has long been supportive of the US fossil fuel industry and, since his reelection, has appointed several former industry lobbyists to top political positions.

According to the Trump administration, national security requires gutting support for renewable energy while performing political CPR on the dying coal industry.

The reality is that, since 2019, the US has produced more oil, gas and coal annually than Americans want to use, with the rest exported and sold overseas. It is currently one of the most prolific exporters of fossil fuels in the world.

In short, the US does not have an energy security problem. It does, however, have an energy cost problem combined with a growing climate change crisis. These issues will only be made worse by Trump’s enthusiasm for fossil fuels.

Over the past six months, the Trump administration has upended half a decade of green industrial policy. It has clawed back billions of US dollars in tax credits and grants that were supercharging American energy innovation.

Meanwhile, China has roared forward. Beijing has doubled down on wind, solar and next‑generation batteries, installing more wind and solar power in 2024 than the rest of the world combined. To China’s delight, the US has simply stopped competing to be the world’s clean energy powerhouse.

Roughly one-in-five lithium‑ion batteries, a key component in clean energy products, are made in China. Many of the newest high‑tech batteries are also being developed and patented there. While Trump repeats the tired mantra of “drill, baby, drill”, China is building factories, cornering the market for critical minerals such as lithium and nickel, and locking in export partners.

At the same time, household energy spending in the US is expected to increase by US$170 (£126) each year between now and 2035 as a result of Trump’s One Big Beautiful Bill Act. The bill, which includes sweeping changes to taxes, social security and more, will raise energy costs mainly because it strips away support for cheap and abundant renewables like wind and solar.

Household energy costs could go up even more as Trump threatens to make large‑scale clean energy development much more onerous by putting up bureaucratic hurdles. The administration recently issued a directive requiring the secretary of the interior to approve even routine activities for wind and solar projects connected to federal lands.

Meanwhile, climate change is hitting American communities harder with each passing year. As recent flooding in Texas and urban fires in California and Hawaii have shown, fewer Americans still have the luxury of ignoring climate change.

As the cost of these disasters mount – US$183 billion in 2024 – the grifting of the oil and gas industry will become an increasingly bitter pill for the nation to swallow.

China’s foresight

China, with its authoritarian government, is less susceptible to the petroleum-obsessed dogma fueling the Republican party. It does not have prominent leaders like US politician Marjorie Taylor Greene, who previously warned that Democrats are trying to “emasculate the way we drive” by advocating for electric vehicles. Rather, China’s leaders are seeing green – not in the environmental sense, but in a monetary one.

It is generally cheaper nowadays to build and operate renewable energy facilities than gas or coal power stations. According to a June 2025 report by Lazard, an asset management company, electricity from new large-scale solar farms costs up to US$78 per megawatt hour – and often much less. The same electricity from a newly built natural gas plants, by comparison, can cost as much as US$107 per megawatt hour.

Across the world, utilities are embracing clean energy, choosing lower costs for their customers while reducing pollution. China saw the writing on the wall decades ago, and its early investments are bearing a rich harvest. It now produces more than half of the world’s electric vehicles and the vast majority of its solar panels.

Wind turbines on top of green mountains.
The Heyuan Queyashan wind farm near the Chinese city of Heyuan, Guangdong province.
maple90 / Shutterstock

The US can still compete at the leading edge of the energy sector. American companies are developing innovative new approaches to geothermal, battery recycling and many other energy technologies.

But in the battle to become the world’s 21st-century energy manufacturing powerhouse, the US seems to have walked off the playing field.

In Trump’s telling, the US may have simply exited one race and reentered another. But the fossil fuel industry – financially, environmentally and ethically – is obviously a dead end.


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

ref. Why the US is letting China win on energy innovation – https://theconversation.com/why-the-us-is-letting-china-win-on-energy-innovation-261109