Want to make America healthy again? Stop fueling climate change

Source: The Conversation – USA (2) – By Jonathan Levy, Professor and Chair, Department of Environmental Health, Boston University

Extreme heat can threaten human health, but it’s only one way climate change puts lives at risk. Drew Angerer/Getty Images

If you’ve been following recent debates about health, you’ve been hearing a lot about vaccines, diet, measles, Medicaid cuts and health insurance costs – but much less about one of the greatest threats to global public health: climate change.

Anybody who’s fallen ill during a heat wave, struggled while breathing wildfire smoke or been injured cleaning up from a hurricane knows that climate change can threaten human health. Studies show that heat, air pollution, disease spread and food insecurity linked to climate change are worsening and costing millions of lives around the world each year.

The U.S. government formally recognized these risks in 2009 when it determined that climate change endangers public health and welfare.

However, the Trump administration is now moving to rescind that 2009 endangerment finding so it can reverse U.S. climate progress and help boost fossil fuel industries, including lifting limits on greenhouse gas emissions from vehicles and power plants. The administration’s arguments for doing so are not only factually wrong, they’re deeply dangerous to Americans’ health and safety.

Health risks and outcomes related to climate change.
Health risks and outcomes related to climate change.
World Health Organization

As physicians, epidemiologists and environmental health scientists who study these effects, we’ve seen growing evidence of the connections between climate change and harm to people’s health. More importantly, we see ways humanity can improve health by tackling climate change.

Here’s a look at the risks and some of the steps individuals and governments can take to reduce them.

Extreme heat

Greenhouse gases from vehicles, power plants and other sources accumulate in the atmosphere, trapping heat and holding it close to Earth’s surface like a blanket. Too much of it causes global temperatures to rise, leaving more people exposed to dangerous heat more often.

Most people who get minor heat illnesses will recover, but more extreme exposure, especially without enough hydration and a way to cool off, can be fatal. People who work outside, are elderly or have underlying illnesses such as heart, lung or kidney diseases are often at the greatest risk.

Heat deaths have been rising globally, up 23% from the 1990s to the 2010s, when the average year saw more than half a million heat-related deaths. Even in the U.S., the Pacific Northwest heat dome in 2021 killed hundreds of people.

Climate scientists predict that with advancing climate change, many areas of the world, including U.S. cities such as Miami, Houston, Phoenix and Las Vegas, will confront many more days each year hot enough to threaten human survival.

Extreme weather

Warmer air holds more moisture, so climate change brings increasing rainfall and storm intensity, worsening flooding, as many U.S. communities have experienced in recent years. Warm ocean water also fuels more powerful hurricanes.

Increased flooding carries health risks, including drownings, electrocution and water contamination from human pathogens and toxic chemicals. People cleaning out flooded homes also face risks from mold exposure, injuries and mental distress.

A man carries boxes out of a house that flooded up to its second story.
Flooding from hurricanes and other extreme storms can put people at risk of injuries during the cleanup while also triggering dangerous mold growth on wet wallboard, carpets and fabric. This home flooded up to its second flood during Hurricane Irma in 2017.
Sean Rayford/Getty Images

Climate change also worsens droughts, disrupting food supplies and causing respiratory illness from dust and dry conditions as well as wildfires. And rising temperatures and aridity dry out forest and grasslands, making them more vulnerable to catching fire, which creates other health risks.

Air pollution

Wildfires, along with other climate effects, are also worsening air quality around the country.

Wildfire smoke is a toxic soup of microscopic particles (known as fine particulate matter, or PM2.5) that can penetrate deep in the lungs and hazardous compounds such as lead, formaldehyde and dioxins generated when homes, cars and other materials burn at high temperatures. Smoke plumes can travel thousands of miles downwind and trigger heart attacks and elevate lung cancer risks, among other harms.

Meanwhile, warmer conditions favor the formation of ground-level ozone, a heart and lung irritant. Burning of fossil fuels also generates dangerous air pollutants that cause a host of health problems, including heart attacks, strokes, asthma flare-ups and lung cancer.

Infectious diseases

Because they are cold-blooded organisms, insects are directly influenced by temperature. So as temperatures have risen, mosquito biting rates have risen as well. Warming also shortens the development time of disease agents that mosquitoes transmit.

Mosquito-borne dengue fever has turned up in Florida, Texas, Hawaii, Arizona and California. New York state just saw its first locally acquired case of chikungunya virus, also transmitted by mosquitoes.

A world map shows where mosquitos are most likely to transmit the dengue virus
As global temperatures rise, regions are becoming more suitable for mosquitoes to transmit dengue virus. The map shows a suitability scale, with red areas already suitable for dengue transmissions and yellow areas becoming more suitable.
Taishi Nakase, et al., 2022, CC BY

And it’s not just insect-borne infections. Warmer temperatures increase diarrhea and foodborne illness from Vibrio cholerae and other bacteria and heavy rainfall increases sewage-contaminated stormwater overflows into lakes and streams. At the other water extreme, drought in the desert Southwest increases the risk of coccidioidomycosis, a fungal infection known as valley fever.

Other impacts

Climate change can threaten health in numerous other ways. Longer pollen seasons can increase allergen exposures. Lower crop yields can reduce access to nutritious foods.

Mental health can also suffer, with anxiety, depression and post-traumatic stress following disasters, and increased rates of violent crime and suicide tied to high-temperature days.

A older man holds a door for a woman at a cooling center.
New York and many other cities now open cooling centers during heat waves to help residents, particularly older adults who might not have air conditioning at home, stay safe during the hottest parts of the day.
Angela Weiss/AFP via Getty Images

Young children, older adults, pregnant women and people with preexisting medical conditions are among the highest-risk groups. Often, lower-income people are also at greater risk because of higher rates of chronic disease, higher exposures to climate hazards and fewer resources for protection, medical care and recovery from disasters.

What can people and governments do?

As an individual, you can reduce your risk by following public health advice during heat waves, storms and wildfires; protecting yourself against tick and mosquito bites; and spending time in green space that improves your mental health.

You can also make healthy choices that reduce your carbon footprint, such as:

However, there are limits to what individuals can do alone.

Actions by governments and companies are also necessary to protect people from a warmer climate and stop the underlying causes of climate change.

Workplace safety can be addressed through rules to reduce heat exposure for people who work outdoors in industries such as agriculture and construction. Communities can open cooling centers during heat waves, provide early warning systems and design drinking water systems that can handle more intense rainfall and runoff, reducing contamination risks.

Governments can ensure that public transit is available and not overly expensive to reduce the number of vehicles on the road. They can promote clean energy rather than fossil fuels to cut emissions, which can also save money since the cost of solar energy has dropped spectacularly. In fact, both solar and wind energy are less expensive than fossil fuel energy.

Yet the U.S. government is currently going in the opposite direction, cutting support for renewable energy while subsidizing the fossil fuel industries that endanger public health.

To really make America healthy, in our view, the country can’t ignore climate change.

The Conversation

Jonathan Levy receives funding from the National Institutes of Health, the Federal Aviation Administration, the City of Boston, and the Mosaic Foundation.

Howard Frumkin has no financial conflicts of interest to report. He is a member of advisory boards (or equivalent committees) for the Planetary Health Alliance; the Harvard Center for Climate, Health, and the Global Environment; the Medical Society Consortium on Climate Change and Health; the Global Consortium on Climate and Health Education; the Yale Center on Climate Change and Health; and EcoAmerica’s Climate for Health program—all voluntary unpaid positions.

Jonathan Patz receives funding from the National Institutes of Health. He is affiliated with the Medical Society Consortium for Climate and Health, and its affiliate Healthy Climate Wisconsin.

Vijay Limaye is affiliated with the Natural Resources Defense Council.

ref. Want to make America healthy again? Stop fueling climate change – https://theconversation.com/want-to-make-america-healthy-again-stop-fueling-climate-change-269269

How a Sudanese university kept learning alive during war

Source: The Conversation – Africa – By Gihad Ibrahim, Assistant Professor and E-learning Department Head, Mashreq University

The civil war in Sudan began in April 2023, causing death, hunger, displacement and destruction on a huge scale. Gihad Ibrahim, head of e-learning and senior manager at Mashreq University in Sudan’s capital, Khartoum, spoke with The Conversation Africa about how his institution continued to educate thousands of students despite the destruction of its campuses during the ongoing conflict.

What was Mashreq University like before the war?

Mashreq University (established in 2003) was a thriving academic community of over 10,000 students across 10 faculties, including healthcare, engineering, information technology and business. We were known for innovation, being the first in Sudan to offer degrees in fields like artificial intelligence and mechatronics engineering. We ranked highly in both global and national rankings.

Our status as a private university allowed us agility in decision-making and investing in digital infrastructure early, a crucial factor in our later survival. However, our success was also rooted in operating within a national system that, before the war, permitted and accredited such innovation. This highlights a vital policy lesson: governments can foster resilience not by micromanaging, but by creating a regulatory environment that allows universities the autonomy to adapt and invest in their own futures.

Our main campus was in Khartoum North, a hub of student life.

While teaching was primarily in-person, we had already begun integrating online elements for some courses. This digital foundation, though modest, would later become our lifeline.

We established a learning management system back in 2013. When the COVID-19 pandemic struck in 2020, we were among the few Sudanese universities that could transition seamlessly online.

That crisis was a dress rehearsal; it forced us to build a system for blended learning that saved us when a far greater crisis emerged.

What happened when the fighting broke out in April 2023?

The war began on a Saturday morning – a normal teaching day. Students were already commuting. I remember I had a morning meeting with three female students working on their graduation project. I called one of them immediately and told her to warn the others and return home. Unfortunately, one didn’t get the message and was trapped near campus for two weeks – a harrowing reminder of the immediate human cost.

Our first priority was evacuation. But in those first chaotic hours, our information technology team performed a critical act: an emergency cloud backup of all academic records. It was a decision born of foresight, and it preserved the academic history of thousands.

Within weeks, our main campus was occupied by the paramilitary Rapid Support Forces (RSF). They looted laboratories and burned lecture halls. Because of the buildings’ height, they used them as military positions. Our campus was not just damaged; it was weaponised.

How did you keep teaching after such devastation?

Khartoum became a ghost city. With people fleeing in all directions – to other states or across borders to neighbouring countries like Egypt and Saudi Arabia – our university community scattered. The first step was to find them. We launched an online survey to locate our displaced students and staff.

Using that data, we established a network of “teaching centres” in safer locations. We created hubs in Port Sudan (after relocating from the city of Atbara), and internationally in Cairo (in Egypt), Jeddah (in Saudi Arabia), and a virtual campus in the United Arab Emirates (UAE). The UAE group was smaller, but because many students there held temporary “war victim” visas that restricted travel, we offered live virtual classes instead of physical ones.

How does this new teaching model work?

We had to be strategic. We categorised every course:

Non-applied courses (like many in business or theory) moved entirely online.
Applied courses (like lab sciences) were delivered face-to-face at the teaching centres.

Advanced specialised courses were taught live online to all centres simultaneously.

Consistency was key. Each course had a “lead lecturer” who coordinated content across all locations to ensure every student received the same quality. We partnered with local hospitals and factories for practical training, turning a constraint into an opportunity for real-world learning.

Exams were held online on university tablets, but invigilated in person at the centres to ensure integrity. The system was built on flexibility, but also on rigorous standards.

What lessons has Mashreq University learned?

We learned three profound lessons:

Technology is a lifeline. Our pre-war investment in digital infrastructure was what allowed us to survive.

Flexibility and compassion must replace rigid bureaucracy. We focused on the goal – education – not on the old rules.

Crisis can fuel innovation. Many students gained deeper, more relevant experience training in real hospitals and factories than they ever would in a simulated campus lab.

The most powerful moments have been the messages from graduates. They write to thank us, often noting that their peers at other universities are still waiting, their education frozen. One message captures it all:

You gave me my future back.

This reminds us that education is not a luxury; in times of war, it is a testament to normalcy, hope, and the future.

What comes next?

We have already begun refurbishing our main campus in Khartoum North, hoping to return soon. But the old model is gone for good.

This experience has taught us that education has no borders. It can reach anyone, anywhere, if guided by compassion and strategic purpose.

For universities everywhere, our story is a stark lesson: investing in resilient, flexible systems is not just about innovation; in today’s world, it is fundamentally about survival.

The Conversation

Gihad Ibrahim works as the Head of E-learning department at Mashreq University

ref. How a Sudanese university kept learning alive during war – https://theconversation.com/how-a-sudanese-university-kept-learning-alive-during-war-269325

Nana Konadu Agyeman-Rawlings: the first lady who redefined women’s power in Ghana.

Source: The Conversation – Africa (2) – By Nancy Henaku, Lecturer, Department of English, University of Ghana

Tributes for Nana Konadu Agyeman-Rawlings (1948-2025) have been pouring in since her death on 23 October 2025. For many Ghanaians, her broad-ranging empowerment work as leader of the 31st December Women’s Movement is deserving of full recognition. The non-governmental organisation started as a women’s political movement and is still active.

Born on 17 November 1948, she became the wife of Jerry John Rawlings, who governed Ghana from 1981 until he handed over power in 2001.

Mourners, including Ghana’s President John Dramani Mahama, have referenced Agyeman-Rawlings’ social welfare interventions through her organisation as evidence of her achievements. These include the provision of credit facilities and advocacy for women’s and children’s rights. She also established daycare centres for children, adult literacy centres and edible oil extraction industries.

A dimension of Agyeman-Rawlings’ politics that has been mainly overlooked, however, is her rhetorical leadership. This refers to the various persuasive means through which she performed her roles as a public figure.

I am a scholar of English who studies how people use language and other communicative forms (such as sound and visuals) to influence public discourse. I have used rhetorical and linguistic methods to study various sources on Agyeman-Rawlings, including a personal interview I conducted with her in 2017.

Agyeman-Rawlings’ speeches and writing reveal her motivations for shifting prevailing ideas about women’s social roles, her complex responses to public anxieties about her power (real or imagined) and her attempt at disrupting the archives by narrating herself into history.

Advocating for change

Agyeman-Rawlings’ rhetorical leadership transformed the role of the first lady in Ghana. In her own words:

A first lady’s work does not end with the collection of flowers and doing some protocols … I’d rather work and be emulated than to sit down and not do anything and not change anybody’s life.

For this reason, Agyeman-Rawlings spoke and wrote extensively in national and international contexts. Her rhetoric of empowerment centred the plights of women, children and the poor. For instance, she asserted at Beijing that “for us in Africa, the girl child is a special concern.”

Agyeman-Rawlings articulated a cosmopolitan ideology shaped by multiple influences. These include UN rights discourses, the language of mothering (such as nurturing, protecting), liberal feminism with its emphasis on gender reform through legal means, and the populist rhetoric of the Rawlings regime, with its emphasis on people power.

An assessment of Agyeman-Rawlings’ legacy must recognise that speaking and writing for change involve extensive physical, mental and emotional energy. And for many years, under her husband’s military regime, she performed this role without the professional support of a communications team.

The sociologist Mansah Prah describes Agyeman-Rawlings’ tenure as the era of the “grand feminist illusion” because although her organisations were seemingly pro-woman, their activities did not result in substantial changes in the lives of women.

However, as my research suggests, discussions on the limitations of Agyeman-Rawlings’ advocacy must consider at least two factors. First, the patriarchal postcolonial state always constrains women’s mass efforts at transformation. Second, the discourses that influence Agyeman-Rawlings’ rhetoric are themselves contradictory. For instance, the term “empowerment” is a catchall phrase that means different things to different people. Its vagueness makes it a safe political term. It does not radically shift conversations on gender.

Contesting power

Agyeman-Rawlings had an intense political life. One could say that through her gendered advocacy and mass mobilisation, she politicised the first lady role. For that reason, she was highly scrutinised during her active political years. In response to efforts to restrain her power, she drew on ambiguous gendered rhetorics, moral values and familial legacy

She was variously accused of being corrupt, power drunk and ostentatious, often with sexist undertones.

People rumoured that she, as first lady, was the real power behind the presidency. When her husband was preparing to leave office, there were stories that she wanted to succeed him. One news report claims that she countered such allegations by saying: “I have never said anywhere that I want to be president” while implying that she could change her mind if her husband said so. It takes a keen rhetorical intellect to navigate the slippery political terrain Agyeman-Rawlings found herself in.

She remained politically active after her tenure as first lady ended. In 2011, she contested against John Evans Atta Mills, Ghana’s president at the time, for the candidacy of the National Democratic Congress, which she helped form. She would later defect from the party to form her own, the National Democratic Party.

In these complex political tussles, she consistently appealed to morality and truth. In one instance, she countered ten years of media “bashing” by claiming that she had been raised right. Her 2016 acceptance speech for the National Democratic Party candidacy centred on “what is right” for the “people”.

My interview with her and other primary sources point to the influence of the calm, ethical and non-ideological pragmatism of Agyeman-Rawlings’ father, J.O.T. Agyeman, in her appeal to morality. Her father was a technocrat who was connected to Ghanaians belonging to different sides of Ghana’s two main political traditions, the Nkrumahist and the Danquah-Busia traditions. According to Agyeman-Rawlings, her parents’ home was a space for “spirited” conversations shaped by her father’s emphasis on logical and ethical argumentation rather than parochial political interests. This suggests that examining African first ladies merely in relation to their husbands’ politics, however crucial, would be a limited view.

Disrupting the archive

Agyeman-Rawlings wrote a memoir, unusually for a Ghanaian woman politician. As the historian Jean Allman suggests, there is a connection between the erasure of women in Ghanaian politics and the absence of autobiographical writings by nationalist women. My studies argue that Agyeman-Rawlings’ narrative (though incomplete) should be read as a rhetorical disruption of the postcolonial archives. These archives tend to erase or subordinate women’s contributions within a dominant masculine framing of the nation-state.

Agyeman-Rawlings is not the only woman to have laboured for the nation-state. Other women like pro-independence activist Hannah Kudjoe who were involved in similar social welfare activities have been written out of Ghanaian history. Agyeman-Rawlings understood that despite her extensive work, words still mattered if she was to be remembered.

By asserting that “it takes a woman” to “birth” the strength and future of a nation, she boldly inserts a feminine voice into a postcolonial national allegory that centres men. By so doing, she demands a rereading of “great men” like Ghana’s first president, Kwame Nkrumah, and Jerry Rawlings. And in the absence of a Jerry Rawlings autobiography, Agyeman-Rawlings’ writing becomes doubly subversive.

Because women have been historically marginalised from the public sphere, a female politician would be scrutinised whether or not she was vocal. Agyeman-Rawlings chose to be visible and outspoken.

The Conversation

Nancy Henaku 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. Nana Konadu Agyeman-Rawlings: the first lady who redefined women’s power in Ghana. – https://theconversation.com/nana-konadu-agyeman-rawlings-the-first-lady-who-redefined-womens-power-in-ghana-269013

Le marché des chevaux de course : entre passion, économie et patrimoine vivant

Source: The Conversation – in French – By Éric Le Fur, Professeur, INSEEC Grande École

Avec 12 097 ventes, les yearlings sont majoritaires, suivis des juments avec 4 951 ventes et des chevaux d’entraînement avec 3 417 ventes. LukasGojda/Shutterstock

Derrière le glamour des courses hippiques se joue un marché mondial des chevaux de course évalué à 300 milliards de dollars (ou 259,2 milliards d’euros). Véritables actifs vivants, les pur-sang attirent investisseurs et passionnés dans un univers où performances sportives, pedigree et spéculation s’entremêlent. Mais entre prestige et rentabilité, le rapport rendement/risque reste souvent défavorable.

Le monde des courses de chevaux n’est pas seulement un sport, c’est un écosystème économique et culturel, où un actif unique, le cheval de course, concentre enjeux financiers, prestige et tradition. Comprendre ce marché, c’est plonger dans un univers où la performance sportive rencontre l’investissement et la passion. Notre contribution questionne ainsi le risque et le rendement de cet investissement.

Définition et catégories d’un cheval de course

C’est un équidé élevé, dressé et entraîné spécifiquement pour participer à des compétitions officielles de vitesse ou d’endurance. Il ne faut pas le confondre avec un cheval de sport qui est utilisé dans d’autres disciplines équestres, comme le saut d’obstacles, le dressage ou le concours complet. Sa valeur dépend à la fois de sa performance sportive, de sa lignée génétique et de son potentiel de reproduction. Les chevaux de course sont classifiés en fonction de leur âge.


Fourni par l’auteur

Marché des chevaux de course et ventes aux enchères

Contrairement à un actif financier, un cheval est un actif vivant qui peut courir, gagner des compétitions, générer des revenus, participer à la reproduction et être vendu. C’est un marché où la performance sportive et la valeur économique sont fortement liées. Ce marché, mondial, est évalué à 300 milliards de dollars (259,2 milliards d’euros).

La France, le Royaume-Uni et l’Irlande représentent 133 milliards de dollars (114,9 milliards d’euros). Les États-Unis et le Canada totalisent 118 milliards de dollars (101,9 milliards d’euros). Le reste des ventes se répartit entre l’Asie-Océanie (Australie, Chine, Hong-kong et Japon), l’Afrique du Sud, et le Moyen-Orient (Arabie saoudite et les Émirats arabes unis).

Chevaux yearlings, ou chevaux pur-sang anglais, descendants du pur-sang arabe.
ErinDaugherty/Shutterstock

L’événement phare en France est la vente de yearlings d’août aux enchères de Deauville (Calvados), organisée par Arqana, des pur-sang dans leur deuxième année. Depuis plusieurs années, les records dans les ventes aux enchères s’accumulent. Par exemple, le 9 décembre 2023, lors de la vente d’élevage de Deauville, Place-du-Carrousel, une jument de 4 ans a été adjugée 4,025 millions d’euros. Lors de la même vente en 2022, Malavath, une pouliche d’entraînement, a été adjugée 3,2 millions d’euros. Enfin, une pouliche de Dubawi, acquise en 2015 pour 2,6 millions d’euros par Godolphin, l’écurie du cheikh Mohammed Al-Maktoum, émir de Dubaï, détient le record pour un yearling vendu aux enchères publiques en France.

Construction d’un indice de prix pour déterminer le risque et le rendement

Nous utilisons 28 310 ventes aux enchères provenant du site Arqana entre novembre 2016 et novembre 2023. Avec 12 097 ventes, les yearlings sont majoritaires, suivis des juments (4 951 ventes) et des chevaux d’entraînement (3 417 ventes).

Plus de 93 % des ventes sont réalisées à Deauville ; le reste, 1 054 à Saint-Cloud (Hauts-de-Seine), 553 en ligne, 87 à Chantilly (Oise) et 29 à Auteuil (Paris XVIᵉ). Les amateurs représentent 22 % des acheteurs. La difficulté de l’analyse repose sur le fait que chaque cheval possède des caractéristiques uniques (généalogie, pays d’origine, sexe, âge). Afin d’extraire une tendance des prix qui mesure l’évolution de la valeur globale des chevaux de course en prenant en compte leurs attributs spécifiques, nous construisons un indice de prix hédonique.

Évolution de l’indice de prix hédonique pour l’ensemble des chevaux de course.
Fourni par l’auteur

La tendance générale est à la hausse, avec une accélération des prix après la pandémie de Covid-19. Cependant, l’analyse des indices par catégorie révèle des évolutions de prix très différentes. Alors que les chevaux de deux ans, les chevaux d’entraînement et les juments ont connu des tendances stables, voire en baisse, après la pandémie de Covid-19, les yearlings et les pouliches ont atteint des sommets.

Rendements et risques d’un investissement dans les chevaux de course

Nos résultats indiquent des rendements positifs mais faibles. Tous les rendements trimestriels et semestriels sont positifs, suggérant qu’investir dans les chevaux de course pourrait être une opportunité, mais sont généralement inférieurs au taux sans risque.

Par conséquent, investir dans les chevaux de course semble davantage relever de la passion que de la rentabilité financière. Par catégorie, les yearlings sont les plus attractifs pour les investisseurs prêts à prendre des risques, surtout depuis la pandémie de Covid-19.

Autres caractéristiques des chevaux à prendre en compte pour mieux appréhender les rendements

Certaines informations ne sont pas prises en compte dans notre modèle et permettraient probablement d’affiner les résultats. La valeur d’un cheval de course dépend aussi de ses caractéristiques physique, morale et esthétique. Un corps bien proportionné, un cœur puissant, un métabolisme efficace et une récupération rapide sont des éléments clés de la performance et de la longévité. Le tempérament du cheval joue également un rôle crucial. La couleur de la robe, bien qu’elle n’ait aucune influence sur les aptitudes physiques, peut susciter l’attrait commercial. Enfin, dans certaines catégories, les informations sur les performances passées peuvent peser significativement sur le prix.

Compte tenu de ces facteurs, le retour sur investissement des chevaux de course est une équation complexe. Il dépend de la différence entre les prix de revente et d’achat, ou des bénéfices actualisés, incluant le prix de revente. Supposons que l’investissement consiste à acheter un cheval de sa conception à sa mort. Dans ce cas, la valeur actuelle nette prend en compte négativement les prix actualisés de la saillie, de l’élevage, de l’entraînement, du transport et de l’entretien post-carrière, et positivement les bénéfices actualisés des courses et de l’élevage. Il est également nécessaire de prendre en compte les risques de blessure, de maladie et de sous-performance potentielle.

Les chevaux de course représentent-ils davantage un investissement de prestige ou de passion ?

Comme nous le démontrons, les chances de profit sont faibles, et il peut être plus facile de considérer cet investissement comme une dépense récréative. Investir dans un cheval de course peut être émotionnellement gratifiant. Pour les passionnés, le prestige et la passion justifient les pertes.

Posséder un cheval de course pour les élites et la communauté équestre, surtout s’il remporte des courses prestigieuses, est synonyme de reconnaissance. Ainsi, certains investisseurs sont davantage motivés par l’amour des chevaux, la passion des sports équestres et l’excitation des courses que par la rentabilité financière. Il s’agit d’un loisir coûteux, comme les voitures de collection.

The Conversation

Les auteurs ne travaillent pas, ne conseillent pas, ne possèdent pas de parts, ne reçoivent pas de fonds d’une organisation qui pourrait tirer profit de cet article, et n’ont déclaré aucune autre affiliation que leur organisme de recherche.

ref. Le marché des chevaux de course : entre passion, économie et patrimoine vivant – https://theconversation.com/le-marche-des-chevaux-de-course-entre-passion-economie-et-patrimoine-vivant-265991

Nos ancêtres du Paléolithique savaient fabriquer des outils simples et efficaces

Source: The Conversation – in French – By Evgeniya Osipova, Préhistoire, Université de Perpignan Via Domitia

Archéologue sur le site paléolithique du nord de la mer d’Aral. Étude du matériel. E.A. Osipova

L’industrie lithique – soit l’ensemble des objets en pierre taillée, pierre polie et matériel de mouture – est souvent le seul témoignage de la culture matérielle préhistorique qui nous soit parvenu. Or, nos ancêtres disposaient d’un kit d’outillage en pierre très diversifié : à chaque activité correspondait un outil spécifique, en particulier pour tout ce qui touchait à la recherche de nourriture et la découpe de la viande.


La viande était une source d’alimentation importante pour les humains préhistoriques, depuis les premiers hominidés, Homo habilis (entre 2,4 millions et 1,6 million d’années), jusqu’à l’apparition de notre espèce, Homo sapiens archaïque (il y a 300 000 ans). Pour trouver de la viande, ils pratiquaient le charognage opportuniste avec les animaux carnivores, puis bien plus tard, la chasse sélective et spécialisée des animaux herbivores.

Mais parvenir à dégager de la viande des carcasses d’animaux nécessite de réaliser une séquence de gestes complexes, en utilisant des outils performants. Au Paléolithique inférieur (entre 800 000 et 300 000 ans avant notre ère) et Paléolithique moyen (entre 300 000 ans et 40 000 ans), il s’agissait d’outils de découpe : des couteaux ou d’autres outils utilisés comme tels. Au fil du temps et en fonction des sites, certains outils travaillés sur deux faces sont devenus de véritables marqueurs culturels. Il s’agit d’abord des bifaces, ces « outils à tout faire » en pierre taillée, qui sont traditionnellement attribués à la culture acheuléenne (entre 700 000 et 200 000 ans en Europe).

Ce sont ensuite des couteaux à dos – le dos correspondant à une partie du bord de la pièce, aménagée ou naturelle, non tranchante et opposée au bord actif, souvent tranchant – autrement appelés des Keilmesser, qui sont typiques de la culture micoquienne (entre 130 000 et 50 000 ans).

Outils de découpe

Les bifaces sont omniprésents en Eurasie, tandis que les couteaux à dos sont majoritairement concentrés en Europe centrale et orientale, dans le Caucase, dans la plaine d’Europe orientale. Les deux catégories d’outils, souvent utilisés pour plusieurs activités, ont en commun une fonction de découpe.

La partie de l’objet qui sert aux pratiques de boucherie est dotée d’un bord suffisamment tranchant et plus ou moins aigu. La fonction de découpe peut être assurée par des éclats simples non aménagés (c’est-à-dire non travaillés par la main humaine) qui ont souvent un bord assez coupant.

La réalisation de ces outils sophistiqués nécessite à la fois de se procurer les matières premières adaptées et d’avoir des compétences avancées en taille de pierre. Mais nos ancêtres avaient-ils vraiment besoin d’outils aussi complexes et polyfonctionnels pour traiter les carcasses d’animaux ? Existait-il d’autres solutions pour obtenir un outil de découpe aussi efficace ?

Notre étude de la période paléolithique à partir d’outils trouvés en Asie centrale, au Kazakhstan, répond en partie à cette question.

Fracturation intentionnelle

La fracturation intentionnelle est une technique qui consiste à casser volontairement un outil en pierre par un choc mécanique contrôlé fait à un endroit précis. Cette technique a été abordée pour la première fois dans les années 1930 par le préhistorien belge Louis Siret. Elle était utilisée au cours de la Préhistoire et de la Protohistoire pour fabriquer des outils spécifiques : burins et microburins, racloirs, grattoirs… La fracture intentionnelle détermine la forme de l’outil en fonction de l’idée de celui qui le taille.

Mais les pièces fracturées sont souvent exclues des études, car la fracture est généralement considérée comme un accident de taille, qui rend la pièce incomplète. Néanmoins, la fracture intentionnelle se distingue d’un accident de taille par la présence du point d’impact du coup de percuteur, qui a provoqué une onde de choc contrôlée, tantôt sur une face, tantôt sur les deux.

À travers l’étude d’une série de 216 pièces en grès quartzite (soit le tiers d’une collection provenant de huit sites de la région Nord de la mer d’Aral), nous avons découvert une alternative simple et efficace aux outils complexes aménagés sur deux faces.

Les objets sélectionnés dans cet échantillon sont uniquement des pierres intentionnellement fracturées. La majorité des pièces présentent un point d’impact laissé par un seul coup de percuteur, porté au milieu de la face la plus plate de l’éclat de grès quartzite. D’autres pièces, plus rares, montrent la même technique, mais avec l’utilisation de l’enclume. La fracture est généralement droite, perpendiculaire aux surfaces de la pierre, ce qui permet d’obtenir une partie plate – un méplat, toujours opposé au bord coupant d’outil.

La création des méplats par fracturation intentionnelle est systématique et répétitive dans cette région du Kazakhstan. Parmi ces outils, on en trouve un qui n’avait encore jamais été mentionné dans les recherches qui y ont été menées : le couteau non retouché à méplat sur éclat, créé par fracture intentionnelle. Cette catégorie de méplat correspond à une fracture longue et longitudinale, parallèle au bord coupant d’un éclat de pierre.

La fabrication de cet outil peu élaboré et pourtant aussi efficace que le biface et le Keilmesser pour la découpe de la viande prend peu de temps et nécessite moins de gestes techniques. C’est pourquoi ils sont abondants et standardisés dans la collection étudiée.

Avec le biface et le Keilmesser, le couteau à méplat sur éclat pourrait ainsi être le troisième outil de découpe du Paléolithique ancien, utilisé dans la région de la mer d’Aral. Les recherches à venir permettront de mieux comprendre le comportement gastronomique de nos ancêtres et d’en savoir plus sur leurs kits de « couverts » en pierre.

The Conversation

Cette recherche a été financée par une subvention du Comité de la Science du Ministère de la Science et de l’Enseignement supérieur de la République du Kazakhstan (Projet N° AP22788840 « Études archéologiques des sites paléolithiques de la région Est de la Mer d’Aral »).

Rimma Aminova, Saule Rakhimzhanova et Yslam Kurmaniyazov ne travaillent pas, ne conseillent pas, ne possèdent pas de parts, ne reçoivent pas de fonds d’une organisation qui pourrait tirer profit de cet article, et n’ont déclaré aucune autre affiliation que leur poste universitaire.

ref. Nos ancêtres du Paléolithique savaient fabriquer des outils simples et efficaces – https://theconversation.com/nos-ancetres-du-paleolithique-savaient-fabriquer-des-outils-simples-et-efficaces-263352

New technologies like AI come with big claims – borrowing the scientific concept of validity can help cut through the hype

Source: The Conversation – USA (2) – By Kai R. Larsen, Professor of Information Systems, University of Colorado Boulder

Closely examining the claims companies make about a product can help you separate hype from reality. Flavio Coelho/Moment via Getty Images

Technological innovations can seem relentless. In computing, some have proclaimed that “a year in machine learning is a century in any other field.” But how do you know whether those advancements are hype or reality?

Failures quickly multiply when there’s a deluge of new technology, especially when these developments haven’t been properly tested or fully understood. Even technological innovations from trusted labs and organizations sometimes result in spectacular failures. Think of IBM Watson, an AI program the company hailed as a revolutionary tool for cancer treatment in 2011. However, rather than evaluating the tool based on patient outcomes, IBM used less relevant measures – possibly even irrelevant ones, such as expert ratings rather than patient outcomes. As a result, IBM Watson not only failed to offer doctors reliable and innovative treatment recommendations, it also suggested harmful ones.

When ChatGPT was released in November 2022, interest in AI expanded rapidly across industry and in science alongside ballooning claims of its efficacy. But as the vast majority of companies are seeing their attempts at incorporating generative AI fail, questions about whether the technology does what developers promised are coming to the fore.

Black screen with IBM Watson logo on a Jeopardy stand with $1,200 stood between two contestants with $0 each
IBM Watson wowed on Jeopardy, but not in the clinic.
AP Photo/Seth Wenig

In a world of rapid technological change, a pressing question arises: How can people determine whether a new technological marvel genuinely works and is safe to use?

Borrowing from the language of science, this question is really about validity – that is, the soundness, trustworthiness and dependability of a claim. Validity is the ultimate verdict of whether a scientific claim accurately reflects reality. Think of it as quality control for science: It helps researchers know whether a medication really cures a disease, a health-tracking app truly improves fitness, or a model of a black hole genuinely describes how it behaves in space.

How to evaluate validity for new technologies and innovations has been unclear, in part because science has mostly focused on validating claims about the natural world.

In our work as researchers who study how to evaluate science across disciplines, we developed a framework to assess the validity of any design, be it a new technology or policy. We believe setting clear and consistent standards for validity and learning how to assess it can empower people to make informed decisions about technology – and determine whether a new technology will truly deliver on its promise.

Validity is the bedrock of knowledge

Historically, validity was primarily concerned with ensuring the precision of scientific measurements, such as whether a thermometer correctly measures temperature or a psychological test accurately assesses anxiety. Over time, it became clear that there is more than just one kind of validity.

Different scientific fields have their own ways of evaluating validity. Engineers test new designs against safety and performance standards. Medical researchers use controlled experiments to verify treatments are more effective than existing options.

Researchers across fields use different types of validity, depending on the kind of claim they’re making.

Internal validity asks whether the relationship between two variables is truly causal. A medical researcher, for instance, might run a randomized controlled trial to be sure that a new drug led patients to recover rather than some other factor such as the placebo effect.

External validity is about generalization – whether those results would still hold outside the lab or in a broader or different population. An example of low external validity is how many early studies that work in mice don’t always translate to people.

Construct validity, on the other hand, is about meaning. Psychologists and social scientists rely on it when they ask whether a test or survey really captures the idea it’s supposed to measure. Does a grit scale actually reflect perseverance or just stubbornness?

Finally, ecological validity asks whether something works in the real world rather than just under ideal lab conditions. A behavioral model or AI system might perform brilliantly in simulation but fail once human behavior, noisy data or institutional complexity enter the picture.

Across all these types of validity, the goal is the same: ensuring that scientific tools – from lab experiments to algorithms – connect faithfully to the reality they aim to explain.

Evaluating technology claims

We developed a method to help researchers across disciplines clearly test the reliability and effectiveness of their inventions and theories. The design science validity framework identifies three critical kinds of claims researchers usually make about the utility of a technology, innovation, theory, model or method.

First, a criterion claim asserts that a discovery delivers beneficial outcomes, typically by outperforming current standards. These claims justify the technology’s utility by showing clear advantages over existing alternatives.

For example, developers of generative AI models such as ChatGPT may see higher engagement with the technology the more it flatters and agrees with the user. As a result, they may program the technology to be more affirming – a feature called sycophancy – in order to increase user retention. The AI models meet the criterion claim of users considering them more flattering than talking to people. However, this does little to improve the technology’s efficacy in tasks such as helping resolve mental health issues or relationship problems.

AI sycophancy can lead users to break relationships rather than repair them.

Second, a causal claim addresses how specific components or features of a technology directly contribute to its success or failure. In other words, it is a claim that shows researchers know what makes a technology effective and exactly why it works.

Looking at AI models and excessive flattery, researchers found that interacting with more sycophantic models reduced users’ willingness to repair interpersonal conflict and increased their conviction of being in the right. The causal claim here is that the AI feature of sycophancy reduces a user’s desire to repair conflict.

Third, a context claim specifies where and under what conditions a technology is expected to function effectively. These claims explore whether the benefits of a technology or system generalize beyond the lab and can reach other populations and settings.

In the same study, researchers examined how excessive flattery affected user actions in other datasets, including the “Am I the Asshole” community on Reddit. They found that AI models were more affirming of user decisions than people were, even when the user was describing manipulative or harmful behavior. This supports the context claim that sycophantic behavior from an AI model applies across different conversational contexts and populations.

Measuring validity as a consumer

Understanding the validity of scientific innovations and consumer technologies is critical for scientists and the general public. For scientists, it’s a road map to ensure their inventions are rigorously evaluated. And for the public, it means knowing that the tools and systems they depend on – such as health apps, medications and financial platforms – are truly safe, effective and beneficial.

Here’s how you can use validity to understand the scientific and technological innovations happening around you.

Because it is difficult to compare every feature of two technologies against each other, focus on which features you value most from a technology or model. For example, do you prefer a chatbot to be accurate or better for privacy? Examine claims for it in that area, and check that it is as good as claimed.

Consider not only the types of claims made for a technology but also which claims are not made. For example, does a chatbot company address bias in its model? It’s your key to knowing whether you see untested and potentially unsafe hype or a genuine advancement.

By understanding validity, organizations and consumers can cut through the hype and get to the truth behind the latest technologies.

The Conversation

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.

ref. New technologies like AI come with big claims – borrowing the scientific concept of validity can help cut through the hype – https://theconversation.com/new-technologies-like-ai-come-with-big-claims-borrowing-the-scientific-concept-of-validity-can-help-cut-through-the-hype-259030

Turn shopping stress into purposeful gift giving by cultivating ‘consumer wisdom’ during the holidays

Source: The Conversation – USA (2) – By Michael Luchs, JS Mack Professor of Business, William & Mary

The most meaningful gifts reflect the giver’s values and identity – and the recipient’s, too. Halfpoint images/Moment via Getty Images

Every fall I anticipate the winter holidays with almost childlike joy. I look forward to familiar traditions with friends and family, eggnog in my coffee, and the sense that everyone is feeling a little lighter and more connected.

At the same time, I feel anxious and annoyed by the manufactured sense of urgency around gift giving: the endless searching and second-guessing shaped by advertisers, retailers and cultural expectations.

Don’t get me wrong, I mostly love giving – and, yes, receiving – gifts during the holidays. But as a researcher who studies consumer psychology, I see how those same forces, amplified by constant buying opportunities and frictionless online payments, make us especially vulnerable and often unwise this time of year.

Buying behavior, including gift giving, doesn’t just reflect needs and wants but also our values. Frequently, the values we talk about are more akin to aspirational ideals. Our actual values are revealed in the seemingly inconsequential choices we make day after day – including shopping.

The cumulative effects of our spending behaviors carry enormous implications for society, the environment and everyone’s well-being – from the purchaser and recipient to people working throughout the supply chain. This makes consumer behavior an especially important place to apply the emerging social science research on wisdom. While wisdom is defined in different ways, it can be understood as seeing decisions through a broader, values-informed perspective and acting in ways that promote well-being.

Over the past decade, consumer psychology researcher David Mick and I have studied what that means when it comes to consumption. “Consumer wisdom?” you may wonder. Isn’t that an oxymoron?

But there are vast differences in how we consume – and as our research shows, this can lead to very different effects on individual well-being.

Defining consumer wisdom

Building on some of David’s earlier work, I began my own research on consumer wisdom in the summer of 2015, interviewing dozens of people across the U.S. whom others in their communities had identified as models of wisdom. Previous research guided me to settings where I could easily find people who represented different aspects of wisdom: practicality on farms in upstate New York; environmental stewardship in Portland, Oregon; and community values in Tidewater, Virginia.

I didn’t use the term “wisdom,” though. It can be intimidating, and people often define it narrowly. Instead, I spoke with people whose peers described them as exemplary decision-makers – people leading lives that considered both the present and the future, and who balanced their needs with others’ needs.

'A woman wearing a green headscarf and holding a credit card in one hand smiles as she looks down at a tablet.
Consumer wisdom helps support well-being – and not just the purchaser’s.
Fajrul Islam/Moment via Getty Images

From those conversations, David and I developed a theory of consumer wisdom. With the help of a third co-author, Kelly Haws, we validated this framework through national surveys with thousands of participants, creating the consumer wisdom scale.

The scale shows how consumer wisdom is not some lofty ideal but a set of practical habits. Some are about managing money. Some are about goals and personal philosophy, and others are about broader impact.

We have found that six dimensions capture the vast majority of what we would call consumer wisdom:

  1. Responsibility: managing resources to support a rewarding yet realistic lifestyle.
  2. Purpose: prioritizing spending that supports personal growth, health and relationships.
  3. Perspective: drawing on past experiences and anticipating future consequences.
  4. Reasoning: seeking and applying reliable, relevant information; filtering out the noise of advertising and pop culture.
  5. Flexibility: being open to alternatives such as borrowing, renting or buying used.
  6. Sustainability: spending in ways that support the buyer’s social or environmental goals and values.

These are not abstract traits. They are everyday ways of aligning your spending with your goals, resources and values.

Importantly, people with higher scores on the scale report greater life satisfaction, as well as better health, financial security and sense of meaning in life. These results hold even after accounting for known determinants of well-being, such as job satisfaction and supportive relationships. In other words, consumer wisdom makes a distinctive and underappreciated contribution to well-being.

A man and woman who appear to be in the 60s or 70s pause and look at a product as they push a grocery cart through a market.
One tenet of consumer wisdom is sustainability: Does your purchase support the world you want to live in?
Luis Alvarez/Digital Vision via Getty Images

Putting it in practice

These six dimensions offer a different lens on holiday norms – one that can reframe how to think about gifts.

Interestingly, the English word “gift” traces back to the Old Norse rune gyfu, which means generosity. It’s a reminder that true giving is not about checking boxes on referral, revenue-generating gift guides or yielding to slick promotions or fads. Generosity is about focusing on another person’s well-being and our relationship with them.

From the perspective of consumer wisdom, that means asking what will genuinely contribute to the recipient’s life. One of the most important dimensions of consumer wisdom is “purpose”: the idea that thoughtful spending can nurture personal growth, health, enjoyment and sense of connection. Out with trendy gadgets, fast fashion and clutter-creating décor or knickknacks – things that feel exciting in the moment but are quickly forgotten. In with quality headphones, a shared cooking class, a board game, and a workshop or tools to support a hobby – gifts that can spark growth, joy and deeper connection.

In my ongoing research, people have described wise gifts as those that define value from the recipient’s perspective – gifts that stay meaningful and useful over time. The wisest gifts, respondents say, also affirm the recipient’s identity, showing that the giver truly understands and values them.

Wiser consumption is learnable, measurable and consequential. By choosing gifts that reflect purpose and the original spirit of “gyfu” – true generosity – we can make the holidays less stressful. More importantly, we can make them more meaningful: strengthening relationships in ways that bring joy long after.

The Conversation

Michael Luchs received funding from the Templeton Foundation through a grant from the University of Chicago School of Divinity.

ref. Turn shopping stress into purposeful gift giving by cultivating ‘consumer wisdom’ during the holidays – https://theconversation.com/turn-shopping-stress-into-purposeful-gift-giving-by-cultivating-consumer-wisdom-during-the-holidays-265564

Paris grapples with the remembrance of terrorist attacks, from 1974 to November 13, 2015

Source: The Conversation – France in French (3) – By Sarah Gensburger, Directrice de recherche au CNRS, Centre de Sociologie des Organisations Sciences Po Paris, Sciences Po

Since 1974, almost 150 terrorist attacks have either taken place in or departed from Paris. The sinister list includes the attacks against the synagogue on Copernic Street (1980), the Jo Goldenberg restaurant on Rosiers Street in the Marais district (1982), the Tati shop in the rue de Rennes high street (1986), as well as two bomb explosions on the RER B commuter train at Saint-Michel (1995) and Port-Royal (1996) stations. However, only a few attacks continue to be recollected in urban memory. Why have so many fallen into oblivion?

On November 13, 10 years after the Islamist terrorist attacks in Paris and its northern suburb of Saint-Denis, the French capital’s mayor will open a garden in tribute to the victims, located on Saint-Gervais Square at the back of city hall. Well-tended and original, the new memorial site comes after the plaques that were placed in front of the targeted locations of the attacks in November 2016. Some of the names of the victims have already been honoured in other spaces. This is the case, for example, of Lola Saline and Ariane Theiller, who used to work in the publishing industry and whose names adorn a plaque in the interior hall of the National Book Centre in the 7th arrondissement.

The attacks of November 13 have profoundly transformed the Parisian public space. While commemorative plaques are now more numerous and almost systematic, they also shed light on the memory lapses surrounding most of the terrorist attacks that have taken place in the capital since 1974.

Collective memory and oblivion

In Paris, there are now more than 15 plaques commemorating the various attacks that have taken place in the city and paying tribute to their victims. Spread across seven arrondissements, they commemorate the attacks of October 3, 1980 against the synagogue on rue Copernic (16th arrondissement); August 9, 1982 against the kosher restaurant Jo Goldenberg on rue des Rosiers (4th arrondissement); September 17, 1986 against the Tati store on rue de Rennes (6th arrondissement); and the two explosions that targeted the RER B commuter train on July 25, 1995 at Saint-Michel station (5th arrondissement) and December 3, 1996 at Port-Royal station (5th arrondissement).

The rest of these plaques refer to attacks in January, 2015 (11th and 12th arrondissements), and, above all, November 2015 (10th and 11th arrondissements), with the exception of those commemorating the attack that killed Xavier Jugelé on April 20, 2017 on the Champs-Élysées (8th arrondissement), and the attack that killed Ronan Gosnet on May 12, 2018 on rue Marsollier (2nd arrondissement).

Commemorative plaques for the November 13, 2015 attacks.
Fourni par l’auteur

While demonstrating a desire for commemoration, these examples of urban memory also highlight the real memory gap surrounding most of the terrorist attacks that have occurred in Paris in the contemporary period.

How the 1974 attack on the Drugstore Publicis paved the way for modern-day terrorism

The French state has designated 1974 as the starting point of contemporary terrorism. Indeed, this year has been retained as the start of the period that the permanent exhibition of the future Terrorism Memorial Museum aims to cover. And the “victims of terrorism”, who stand apart in France through their right to be awarded a special medal, are those affected by attacks that have occurred since 1974. This choice refers to the attack on the Drugstore Publicis Saint-Germain-des-Prés, which took place in Paris (on the Boulevard Saint-Germain, 6th arrondissement) on September 15 of that year. This chronological milestone is, of course, open to debate, as is any temporal division. However, it is taken here as a given.

Since 1974, historian Jenny Raflik-Grenouilleau has recorded nearly 150 attacks in Paris or originating in Paris in her preliminary research for the Terrorism Memorial Museum. Of this total, 130 attacks resulted in at least one injury and just over 80 resulted in the death of at least one victim. Depending on where one chooses to draw the line between what is worthy of commemoration – from deaths to property damage alone – there are more than 80 attacks and up to nearly 150 in Paris that could potentially have given rise to a permanent memorial in the public space.

The 17 existing plaques therefore concern only a very small minority of the terrorist acts that have taken place in the city. In this respect, the situation in Paris mirrors that described by Kenneth Foote in his pioneering study: plaques are both sources of memory and producers of oblivion. For example, the attack on the Drugstore Publicis Saint-Germain-des-Prés in 1974 left two people dead and thirty-four wounded. Although it is considered the starting point of the contemporary wave of terrorism, there is no plaque to remind passers-by, whether they are Parisians or tourists, many of whom pass through this busy crossroads in the Saint-Germain-des-Prés neighbourhood every day.

Selective narratives and invisible perpetrators

What do the few plaques in Paris that commemorate attacks there have in common?

Firstly, it appears that it is the deadliest attacks that are commemorated, foremost among which, of course, are those of November 13, 2015. All attacks that have claimed at least four lives are commemorated in public spaces. There is only one exception: the bomb attack by a revolutionary brigade in June 1976, which targeted a temporary employment agency to denounce job insecurity. The building’s concierge and her daughter, as well as two residents, were killed.

Only two attacks that resulted in a single death are commemorated: these are the most recent ones, which occurred in 2017 and 2018, and whose victims were named above.

Furthermore, the existing plaques only refer to attacks carried out by Islamist organisations (Armed Islamic Group, al-Qaida, Daesh, etc.) on the one hand, or attacks claimed in the name of defending the Palestinian cause on the other. In this respect, the existing plaques primarily reflect the infinitely more criminal nature of the attacks carried out by these groups, as well as their majority presence. Nevertheless, they consequently only show two sides of terrorism.

Diverse forms of terrorism, but a partial memory

And yet, there has been no shortage of variety since 1974. For example, memory of extreme left-wing terrorism and, to a lesser extent, of extreme right-wing terrorism is nowhere to be found in the public space – notwithstanding their importance in the 1970s and 1980s and the many injuries and deaths left in their wake.

Take, for example, the 1983 attack carried out by far-right group Action Directe at the restaurant Le Grand Véfour, which left Françoise Rudetzki seriously injured as she was having dinner. The event inspired Rudetzski to found SOS Attentats, an organisation that enabled public authorities to compensate terrorism victims. However, even today, there is not a word about the attack on the walls of the building in question in the 1st arrondissement.

The memory gap is all the more puzzling given that the justifications put forward for these invisible attacks have not disappeared. Between July 5 and 21, 1986, Action Directe carried out three successive bomb attacks. The attack on July 9 targeted the police anti-gang squad, killing one officer and injuring 22 others. In their claim, the perpetrators mentioned that they had sought to “avenge” Loïc Lefèvre, a young man killed by a member of the security forces in Paris four days earlier. In October 1988, this time it was Catholic fundamentalists who attacked the Saint-Michel cinema, which was screening Martin Scorsese’s film The Last Temptation of Christ, which they considered blasphemous. The attack injured 14 people. These two examples show how some of the attacks that have remained invisible in the public sphere nonetheless resonate with themes that are still very much present in contemporary public debate, from “police violence” to “freedom of expression”.

Finally, no plaque mentions the motivations of the perpetrators of the attack. Whether they were installed in 1989 or 2018, Paris’s plaques either pay tribute to “the victims of terrorism” or commemorate an “act of terrorism”, without further detail. Although, here too, there is an exception to this rule, which in turn allows us to reflect implicitly through a borderline case. The plaques commemorating the 1982 attack on the kosher restaurant Jo Goldenberg and the 2015 attack on the Hyper Casher supermarket on avenue de la Porte de Vincennes are the only ones to add an adjective, in this case “antisemitic”, to the mention of the attack, while the plaque hung on rue Copernic, which was targeted by a bomb in 1980, refers to “the heinous attack perpetrated against this synagogue”, thus specifying the reason for the attack. To date, only antisemitic attacks are named as such.

Commemorative plaque for the attack on the Jo Goldenberg restaurant on rue des Rosiers.
Fourni par l’auteur

Memorial practices in Parisian public spaces

Only a tiny fraction of the terrorist acts committed in Paris since 1974 are now marked for passers-by’s attention, producing, thereby, memory as well as oblivion. The question of how these reminders of the past are used in Parisian public spaces remains open.

While the issue is not specific to the commemoration of terrorist attacks, it is particularly acute in the case of plaques referring to them, since they refer to an event – “terrorism” – which, unlike a war marked by a beginning and an end, is an ongoing process that is difficult to consider as having ended. In 1996, when the public transport company, the RATP, was asked by the families of the victims of the RER B attack to have their names included on a plaque, it initially expressed its hesitations. It said it feared dangerous crowds on the narrow metro platform. These fears proved unfounded. Very few passengers actually look up to see the plaque.

In this respect, the new November 13, 2015 memorial garden creates a form of commemoration that leaves open the possibility of new ways of remembering, combining the uses of an urban park with participation in the preservation of memory.


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The Conversation

Sarah Gensburger 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. Paris grapples with the remembrance of terrorist attacks, from 1974 to November 13, 2015 – https://theconversation.com/paris-grapples-with-the-remembrance-of-terrorist-attacks-from-1974-to-november-13-2015-269237

Sarkozy interdit de contact avec Darmanin : l’indépendance de la justice renforcée ?

Source: The Conversation – France in French (3) – By Vincent Sizaire, Maître de conférence associé, membre du centre de droit pénal et de criminologie, Université Paris Nanterre

Nicolas Sarkozy a été mis en liberté sous contrôle judiciaire, lundi 10 novembre, par la Cour d’appel de Paris. Il n’a plus le droit de quitter le territoire, et ne doit pas entrer en contact avec les personnes liées à l’enquête ni avec le ministre de la justice Gérald Darmanin. Cette interdiction est liée à la visite que lui a rendu le ministre en prison, interprétée comme une pression exercée sur les magistrats. Le contrôle judiciaire de l’ancien président de la République va donc dans le sens d’une réaffirmation du principe d’indépendance des magistrats vis-à-vis du pouvoir exécutif. Au-delà de l’affaire Sarkozy, quelles sont les capacités d’influence du pouvoir exécutif sur la justice ?


Le 10 novembre 2025, la Cour d’appel de Paris a fait droit à la demande de mise en liberté de Nicolas Sarkozy. Contrairement à ce qu’on pourrait penser, cette décision n’est nullement le résultat des pressions diverses qui pèsent sur l’institution judiciaire depuis le prononcé de la condamnation de l’ancien chef de l’État. D’une part, la Cour d’appel a estimé que les conditions de la détention provisoire n’étaient pas réunies, aucun élément objectif ne laissant craindre que l’ancien chef de l’État soit tenté de prendre la fuite avant le jugement définitif de son affaire. D’autre part, et surtout, la Cour a assorti la mise en liberté d’un contrôle judiciaire strict, interdisant en particulier à M. Sarkozy tout contact avec le garde des sceaux Gérald Darmanin et avec son cabinet, considérant que de tels liens lui permettraient d’influer sur le cours de la procédure.

Ce faisant, la juridiction vient non seulement réaffirmer l’indépendance du pouvoir judiciaire, mais aussi apporter une réponse à la polémique soulevée par la visite du garde des sceaux, agissant à titre officiel, à l’ancien locataire de l’Élysée incarcéré, le 27 octobre. Cette démarche avait en effet suscité de nombreuses critiques au sein du monde judiciaire, à l’image des propos du procureur général de la Cour de cassation dénonçant un risque « d’obstacle à la sérénité et d’atteinte à l’indépendance des magistrats » ou, plus encore, de la plainte pour prise illégale d’intérêt déposée à l’encontre du ministre par un collectif d’avocats.

Le ministre de la justice peut-il rendre visite à un détenu ?

Au-delà de la polémique médiatique, c’est d’abord l’état de la relation entre le pouvoir exécutif et le pouvoir judiciaire – sensément séparés et indépendants – que cette visite interroge. Certes, les textes actuels permettent bien au ministre, au moins indirectement, d’y procéder. Le Code pénitentiaire reconnaît en effet à certains services de l’administration pénitentiaire le droit de procéder à des visites de contrôle du bon fonctionnement des établissements carcéraux. Dans la mesure où le ministre de la justice est à la tête de cette administration, rien ne lui interdit donc, en théorie, de procéder lui-même à de telles visites. Par ailleurs, toute personne détenue « peut demander à être entendue par les magistrats et fonctionnaires chargés de l’inspection ou de la visite de l’établissement, hors la présence de tout membre du personnel de l’établissement pénitentiaire ». Ainsi, le cadre juridique aujourd’hui applicable au contrôle des prisons n’interdit pas au garde des sceaux de visiter lui-même un établissement et de s’entretenir, à cette occasion, avec les personnes incarcérées.

Mais c’est justement un tel cadre qui, du point de vue de la séparation des pouvoirs, mérite d’être questionné. Faut-il le rappeler, c’est toujours en vertu d’une décision de l’autorité judiciaire qu’un individu peut être mis en prison, qu’il s’agisse d’un mandat de dépôt prononcé avant l’audience ou de la mise à exécution d’un jugement de condamnation définitif. C’est également l’autorité judiciaire, en la personne du juge d’application des peines, qui est seule compétente pour décider des mesures d’aménagement des peines d’emprisonnement (réduction de peines, semi-liberté, libération conditionnelle…). Et si la direction de l’administration pénitentiaire peut prendre seule certaines décisions (placement à l’isolement, changement d’établissement…), c’est sous le contrôle du juge administratif, non du ministre.

C’est pourquoi la visite dans un établissement carcéral du garde des sceaux, lequel – à la différence des fonctionnaires placés sous son autorité – est membre du pouvoir exécutif, est toujours porteuse d’un risque d’immixtion ou de pression, au moins indirecte, sur le pouvoir judiciaire. Tel est notamment le cas quand cette visite a pour seul objet d’accorder, sinon un soutien, du moins une attention particulière à un détenu parmi d’autres, quand les juges ont pour mission de traiter chacun d’entre eux sur un strict pied d’égalité.

À cet égard, il est intéressant de relever que les autres autorités habilitées – aux côtés des magistrats – à se rendre en prison ont, quant à elles, pour seule attribution de veiller au respect des droits fondamentaux de l’ensemble des personnes emprisonnées, à l’image du défenseur des droits et du contrôleur général des lieux de privation de liberté ou, encore, du comité de prévention de la torture du conseil de l’Europe.

Les leviers du pouvoir exécutif sur le pouvoir judiciaire

La polémique suscitée par la visite faite à l’ancien chef de l’État a ainsi le mérite de mettre en lumière à quel point le pouvoir exécutif dispose, encore aujourd’hui, de nombreux leviers pour intervenir plus ou moins directement dans le champ d’intervention du pouvoir judiciaire. Ainsi, ce qui est vrai pour l’exécution des peines l’est, plus encore, pour l’exercice de la police judiciaire, c’est-à-dire l’ensemble des actes ayant pour objet la constatation et l’élucidation des infractions pénales. Alors que l’ensemble des agents et officiers de police judiciaire sont en principe placés sous l’autorité exclusive du procureur de la République ou – lorsqu’il est saisi – du juge d’instruction, ils demeurent en pratique sous l’autorité du ministre de l’intérieur, seul compétent pour décider de leur avancement, de leurs mutations et, plus largement, de leurs conditions générales de travail. C’est en particulier le ministère qui décide, seul, de l’affectation des agents à tel ou tel service d’enquête, du nombre d’enquêteurs affectés à tel service et des moyens matériels qui leur sont alloués. En d’autres termes, les magistrats chargés des procédures pénales n’ont aucune prise sur les conditions concrètes dans lesquelles leurs instructions peuvent – ou non – être exécutées par les services de police.

Mais le pouvoir exécutif dispose d’autres leviers lui permettant d’exercer encore plus directement son influence sur le cours de la justice. Les magistrats du parquet sont ainsi placés sous la stricte subordination hiérarchique du garde des sceaux, seul compétent pour décider de leur affectation, de leur avancement, et des éventuelles sanctions disciplinaires prises à leur encontre.

Une situation de dépendance institutionnelle qui explique que, depuis plus de quinze ans, la Cour européenne des droits de l’homme considère que les procureurs français ne peuvent être regardés comme une autorité judiciaire au sens du droit européen. Si les magistrats du siège bénéficient quant à eux de réelles garanties d’indépendance, ils ne sont pas à l’abri de toute pression. Certes, ils sont inamovibles et le Conseil supérieur de la magistrature a le dernier mot sur les décisions disciplinaires et les mutations les concernant. Toutefois, si les juges ne peuvent être mutés contre leur gré, c’est le ministère qui reste compétent pour faire droit à leurs demandes de mutation, le Conseil n’intervenant que pour valider (ou non) les propositions faites par les services administratifs – à l’exception des présidents de tribunal et des magistrats à la Cour de cassation, qui sont directement nommés par le Conseil supérieur de la magistrature.

Des juridictions dépendantes du ministère pour leur budget

Par ailleurs, alors que le conseil d’État négocie et administre en toute indépendance le budget qui lui est confié pour la gestion des juridictions de l’ordre administratif, les juridictions judiciaires ne bénéficient quant à elles d’aucune autonomie budgétaire. Là encore, c’est le ministère de la justice qui, seul, négocie le budget alloué aux juridictions et prend les principales décisions quant à son utilisation, notamment en matière d’affectation des magistrats et des greffiers à telle ou telle juridiction et en matière immobilière. Le pouvoir exécutif dispose ainsi d’une influence considérable sur l’activité concrète des tribunaux et, en particulier, sur leur capacité à s’acquitter de leurs missions dans de bonnes conditions.

Au final, c’est peu dire qu’il existe de significatives marges de progression si l’on veut soustraire pleinement le pouvoir judiciaire à l’influence du pouvoir exécutif. Une émancipation qui, faut-il le rappeler, n’aurait pas pour fonction d’octroyer des privilèges aux magistrats, mais tendrait uniquement à assurer à tout justiciable – et, plus largement, à tout citoyen – la garantie d’une justice véritablement indépendante, à même d’assurer à chaque personne le plein respect de ses droits, quelle que soit sa situation sociale.

The Conversation

Vincent Sizaire 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. Sarkozy interdit de contact avec Darmanin : l’indépendance de la justice renforcée ? – https://theconversation.com/sarkozy-interdit-de-contact-avec-darmanin-lindependance-de-la-justice-renforcee-269620

Des accélérateurs de particules pour comprendre la cuisson parfaite des pâtes

Source: The Conversation – in French – By Andrea Scotti, Senior lecturer of Physical Chemistry, Lund University

Et si la physique des particules pouvait améliorer la cuisson des pâtes ? En scrutant leur structure à l’échelle atomique, des chercheurs ont compris comment le gluten maintient la fermeté des spaghettis et pourquoi les versions sans gluten restent si fragiles.


Que vous préfériez vos spaghettis al dente ou délicieusement fondants, il n’est pas toujours facile d’atteindre la perfection à la maison. Beaucoup d’entre nous ont déjà vu leurs pâtes se transformer en une bouillie beige – surtout lorsqu’il s’agit d’alternatives sans gluten.

Alors, quelle quantité d’eau et de sel faut-il vraiment utiliser, et combien de temps faut-il cuire les pâtes pour obtenir un résultat optimal ? Et surtout, comment adapter sa méthode de cuisson quand on utilise des pâtes sans gluten ? Une étude récente que mes collègues et moi avons menée, publiée dans Food Hydrocolloids, apporte des réponses en dévoilant la physique du processus de cuisson.

En nous tournant vers le Diamond Light Source, le synchrotron national du Royaume-Uni (un accélérateur de particules circulaire), nous avons étudié la diffusion des rayons X sur des pâtes afin d’en révéler la structure interne. Nous nous sommes ensuite rendus à Isis et à l’Institut Laue-Langevin, deux centres de recherche situés respectivement au Royaume-Uni et en France, pour analyser à l’aide de neutrons (qui, avec les protons, composent le noyau atomique) la microstructure des spaghettis classiques et sans gluten soumis à différentes conditions de cuisson.

L’étude montre comment la structure cachée des pâtes se modifie au cours de la cuisson, et pourquoi les versions sans gluten se comportent de manière si différente.

Ce dispositif nous a permis d’examiner la structure de l’amidon et du gluten dans les spaghettis à des échelles très fines, allant de plusieurs dizaines de fois le rayon d’un atome à plusieurs milliers de fois. Nous avons ainsi pu comparer les transformations qui s’opèrent dans les pâtes classiques et sans gluten selon diverses conditions de cuisson – par exemple lorsqu’elles sont trop cuites ou cuites sans sel.

Nos expériences nous ont permis de « voir » séparément les différents composants des pâtes. En mélangeant de l’eau normale et de « l’eau lourde » (qui contient un isotope appelé deutérium), nous pouvions rendre soit le gluten, soit l’amidon invisible au faisceau de neutrons. De cette manière, nous avons pu isoler efficacement chaque structure à tour de rôle et comprendre le rôle respectif de l’amidon et du gluten pendant la cuisson.

Le rôle du gluten et du sel

Notre étude montre que, dans les pâtes classiques, le gluten agit comme une armature solide qui maintient les granules d’amidon en place même pendant l’ébullition, ce qui confère aux pâtes leur fermeté et leur lenteur de digestion. Dans les pâtes sans gluten, en revanche, les granules d’amidon gonflent et s’effondrent plus facilement – ce qui explique leur texture pâteuse et leur dégradation plus rapide lorsque ce type de pâtes est cuit dans des conditions non optimales.

Nous avons également étudié l’effet du sel contenu dans l’eau de cuisson sur la structure des pâtes. Nous avons constaté que le sel ne se contente pas d’améliorer leur goût : il influence fortement la microstructure des spaghettis. Lorsque des pâtes classiques sont bouillies dans une eau salée, le gluten conserve sa structure, et les granules d’amidon sont moins altérés par le processus de cuisson.

Alors, quelle quantité de sel faut-il ajouter pour préserver la structure microscopique des pâtes ? Notre étude a révélé que l’idéal est de sept grammes de sel par litre d’eau, avec une quantité d’eau plus importante nécessaire pour de plus grandes portions de pâtes. Le temps de cuisson idéal est de dix minutes pour les pâtes classiques et onze minutes pour les pâtes sans gluten. À l’inverse, lorsque la concentration en sel était doublée, l’ordre interne se dégradait plus rapidement et la structure des granules d’amidon était significativement altérée par la cuisson.

Spaghetti is taken out of the pan with tongs
La quantité idéale est de 7 grammes de sel par litre d’eau.
Kalashnikov Dmitrii/Shutterstock

Pour les pâtes sans gluten, les conclusions étaient encore différentes en raison de l’absence de la protection offerte par le gluten. Même de petites quantités de sel ne pouvaient compenser cette absence. Les composés artificiels à base d’amidons transformés, utilisés par les fabricants pour remplacer le gluten, se dégradaient rapidement. L’exemple le plus extrême de cette dégradation est survenu lorsque les spaghettis sans gluten étaient cuits trop longtemps – par exemple treize minutes au lieu de onze – et dans une eau très salée.

La principale conclusion est donc que les pâtes sans gluten sont structurellement plus fragiles et moins tolérantes à une cuisson prolongée ou à une mauvaise proportion de sel.

Améliorer les alternatives sans gluten

Comprendre la structure des pâtes à des échelles aussi infimes, invisibles même au microscope, aidera à concevoir de meilleurs aliments sans gluten. L’objectif est notamment de créer des alternatives sans gluten plus résistantes aux mauvaises conditions de cuisson et dont la texture se rapproche davantage de celle des spaghettis classiques.

Les pâtes de blé classiques ont un faible indice glycémique, car le gluten ralentit la dégradation des granules d’amidon lors de la digestion. Les pâtes sans gluten, fabriquées à partir de farines de riz et de maïs, manquent souvent de cette structure, ce qui entraîne une libération plus rapide des sucres. Grâce à la diffusion des neutrons, les scientifiques de l’alimentation peuvent désormais identifier quels ingrédients et quelles conditions de cuisson reproduisent le mieux la structure du gluten.

C’est aussi une illustration de la manière dont des outils expérimentaux de pointe, principalement utilisés pour la recherche fondamentale, transforment aujourd’hui la recherche alimentaire. La diffusion des neutrons a joué un rôle essentiel dans la compréhension des matériaux magnétiques, des batteries, des polymères et des protéines. Elle permet désormais aussi d’expliquer le comportement de nos aliments du quotidien à l’échelle microscopique.

The Conversation

Andrea Scotti reçoit des financements de la Fondation Knut et Alice Wallenberg ainsi que du Conseil suédois de la recherche.

ref. Des accélérateurs de particules pour comprendre la cuisson parfaite des pâtes – https://theconversation.com/des-accelerateurs-de-particules-pour-comprendre-la-cuisson-parfaite-des-pates-269202