During his PhD research, mathematician Tyron Lardy worked on a new approach to hypothesis testing. Instead of the traditional p-value, he uses so-called e-values. These turn out to be more flexible – especially when you want to look at your results midway through the study.

As a mathematician, Fred Rohde (1948) explored the world of numbers. As a photographer, he captured demonstrations. And now he’s reconstructing his mother’s wartime story – an extraordinary tale of her stay with an Austrian family, the inventors of asbestos cement.

On 24 January 2026, the Advanced MSc International Relations and Diplomacy (MIRD) hosted its Annual Reconnect & Gala, bringing together alumni from across the world, current students, and faculty. The event celebrated shared values, connection, and purpose, focusing on ‘The great shifts in international…

Inaugural lecture Marc Bruijnzeels

Minister Dijkgraaf van onderwijs wil het aantal internationale studenten terugdringen. Maar mag Nederland dat wel? En zo ja, is het ook wenselijk? Deze vragen behandelde Mark Klaassen, universitair docent bij het Europa Instituut, tijdens de slotbijeenkomst van het Honours College Law op 12 juni.

Henk Hoekstra and Alessandra Silvestri work on the astronomy and theoretical physics in the Euclid mission. These Dutch researchers are part of the mission.

Italian nurse Daniela Poggiali was arrested and convicted of murdering two hospital patients in 2014. Her case attracted the attention of Leiden statistician Richard Gill. After his investigation, together with an Italian colleague, Poggiali was acquitted last autumn. Together with fellow statisticians,…

How safe are the nanoparticles in transparent sunscreen, anti-odour socks and bacteria-resistant plasters? Although microbes are present on all organisms, the tools that estimate the safety of nanomaterials still hardly take them into account. Bregje Brinkmann explored the role of these microbes during…

In less than a week’s time, millions of Turkish people are going to decide who will govern their country for the next five years. These elections promise to be the most closely contested in years, with the opinion polls showing very small differences and everything at stake, including for Europe. Alp…

While tens of thousands of visitors dance to deafening music, a team of Leiden psychologists are trying to collect data for their research at Lowlands. How do festivalgoers experience a virtual trip? And what role do factors such as too little sleep and whether they have experience with psychedelics…

Jasper Knoester is the dean of the Faculty of Science. How is he doing, what exactly does he do and what does his day look like? In each newsletter, Jasper gives an insight into his life.

When Sjoerd van Trigt, a student of International Studies, is not in the lecture hall, you can find him at Rowing Club Asopos de Vliet. He trains there seven times a week. Soon, he will be leaving for a six-month stay in Japan.

Leiden University has set up two committees to consider issues that are the focus of much attention within our community and society at large. They are the Knowledge Security Committee and the Fossil Fuel Industry Collaboration Committee. Former dean Joanne van der Leun will chair both.

Are we on the right track towards a circular economy in 2050, with fully renewable energy technology and circular construction? The CML of Leiden University, together with the Netherlands Environmental Assessment Agency (PBL), TNO, Utrecht University and RIVM, is investigating what is needed to achieve…

The prestigious journal Science Translational Medicine has published a study by researchers from the Institute of Biology Leiden (IBL) on a potent new antibiotic that can overcome resistance. ‘The idea was to tweak the original antibiotic and create a next-generation drug’, says Nathaniel Martin, professor…

White girls receive significantly more positive comments from their teachers in their primary school reports than white boys and children from migrant backgrounds. PhD candidate Antoinette Kroes researched subtle biases in different contexts and saw how harmful these can be.

A professor from Leiden University, together with a former employee (who is also the professor’s partner), has been guilty of long-term unacceptable and often transgressive behaviour in the form of abuse of power and manipulation. This behaviour led to a culture of fear among staff who were largely…

In the new ‘Educatips’ column, Psychology lecturers share their most important lessons about teaching. This month: Elise Seip wants to help students get out of their head and into their body. She starts every work group with mindfulness.

One used 3D cell models to study colorectal cancer, while the other used machine learning for more efficient blood donation. For these achievements, Marieke Vinkenoog and Simon Christian Hansmann were awarded the Krijn Rietveld Memorial Innovation Award on Tuesday 2 September.

Intelligence and security services often operate in the shadows. Michael Kowalski calls for a clear, applied ethical framework as the foundation of intelligence work in a democracy.

Information provided by the Tax and Customs Administration is something that concerns every citizen. So it is not surprising that the Tax hotline receives around 10 million calls each year. The Benefits Affair emphasised the citizen’s perspective in communications with the Tax and Customs Administration.…

Jasper Knoester is the dean of the Faculty of Science. How is he doing, what exactly does he do and what does his day look like? In each newsletter, Jasper gives an insight into his life.

In the fight for a liveable planet, we desperately need a fairer distribution of wealth and equal rights for all, argues anthropology professor Marja Spierenburg. ‘That will also generate broad-based support for sustainable development.’

The Schoof cabinet has presented its budget. As expected, higher education is facing severe cuts. In the coming period, the Executive Board will regularly look at the consequences of what it deems an irresponsible policy.

For decades, linguists have racked their brains over the question of precisely how the syntax of various languages is different. PhD candidate Martin Kroon has developed a computer system that brings us closer to finding an answer. His PhD defence is on 10 November.

Following the news that TomTom is cutting 300 jobs due to the use of artificial intelligence (AI), FGGA researchers Friso Selten and Alex Ingrams responded with opinion pieces. They place the news in a broader context and call for a more nuanced debate on AI and job losses.

All acute care staff at Leiden University Medical Center have received their first and sometimes even their second dose of the coronavirus vaccine. But how long will you be protected after vaccination and what does the genetic material of the virus do in the vaccine? Our virologists Ann Vossen and Leo…

What if seriously ill patients do not want to hear their diagnosis? Does a clinician always need to provide a patient with all available information? Communication researcher Liesbeth van Vliet, medical anthropologist Annemarie Samuels and research intern Fiona Brosig will put these questions on open…

Leiden University has recently received various petitions from students and staff concerning our ties with Israeli universities. We have also held extensive discussions with the University Council in response to questions raised on the subject. We think it important that our partners and research projects…

In the ‘Educatips’ column, lecturers in Child and Education studies share their most important insights on teaching. This month: Tirza Smits, Kim Stroet and Marit Guda observed frustration among students working in groups, often due to poor communication. So they decided to build a tool to help.

The Rutte IV cabinet is more or less complete. It includes more women than ever. For the first time ever, the Netherlands will have two ethnic minority ministers, and ministers without political experience but with plenty of professional expertise will also be making their debut. However, political…

Dutch mosquitos are more resilient to saltwater than previously thought. Environmental scientist Sam Boerlijst discovered this during his PhD research at the Hortus botanicus. This knowledge is crucial for understanding how mosquito-borne disease transmission might change in the future.

Terrorism, crisis, violence, intelligence, diplomacy, war and peace are topics that are broadly covered in ISGA's research activities. Regularly, ISGA researchers appear in international media to discuss their research expertise. This item offers an overview of non-Dutch and non-English articles and…

This spring BA International Studies will be a focus of investigation! An investigation we invite you to become an active participant in, by joining in and discussing some profound questions in order to build a strong(er) community in the uncertainty of the world around us.

Can humans perceive single photons? What is our place in the universe? How can we make quantum computers more stable? Five researchers from the Faculty of Science have received funding for their research projects within the Dutch Research Agenda (NWA).

Governments worldwide invest huge sums in their digital services and data strategies. Efficiency and effectiveness are key. But these are not achieved for some people at least, says Professor of Public Policy Sarah Giest. This makes the intended digital inclusion far from inclusive, as she will explain…

Registering your hypothesis and analysis plan online before starting your study – why should researchers bother? Henk van Steenbergen, a researcher in cognitive psychology, decided to give it a try. 'I used it as an exercise in open science.'

"Climate citizenship” explores how adapting environments to climate change can change the way people interact with each other and with government. It focuses on nature-based or 'green' climate infrastructure projects that make use of natural entities or dynamics. With an ERC grant, anthropologist Andrew…

By chance, computer scientist Hans-Dieter Hiep (Leiden Institute of Advanced Computer Science and Centrum Wiskunde & Informatica) discovered a ‘gaping hole’ in a widely used method for evaluating software security. Hiep patched the hole, causing quite a stir in his field. 'It’s not pleasant when a PhD…

Immunologist Leender Trouw specialises in the complement system, which is part of the immune system. In some diseases drugs help activate or inhibit this system. This is best done ‘in the right place at the right time’ − the title of his inaugural lecture.

As an experiment, student Alicia Cai relied solely on AI tools such as ChatGPT and Claude for supervision while writing her thesis. What lessons were learned?

On 26 and 27 September, Eduard Fosch-Villaronga, Carlotta Rigotti, Mohammed Raiz Shaffique, Marie Schwed-Shenker and Antoni Mut Piña participated in the third edition of Lawtomation Days at the IE University in Madrid.

Infecting each other with viruses and bacteria while protecting yourself with medicines and vaccinations. Sounds like a fun evening, right? Master students Life Science & Technology Rafael Jezior and Dennis de Beeld certainly think so. Together, they developed ImmunoWars: an exciting card game based…

International prosecutors, for instance at the International Criminal Court in The Hague, investigate particularly serious crimes such as genocide. They decide, among other things, whether or not to prosecute. PhD candidate Cale Davis investigated how prosecutors come to such decisions and will defend…

It often takes longer for women with heart problems to get the right diagnosis. In her Annie Romein-Verschoor Lecture, Professor Hester den Ruijter will talk about how hormones influence the heart and the importance of medical research that focuses specifically on women.

People who are attracted to more than one gender often experience a disadvantage in the workplace and labour market. How can the workplace can be improved for bi+ people.

Turkish politics was shaken by the arrest of Istanbul mayor Ekrem İmamoğlu, along with dozens of others from the main opposition party.

Teens with depression appear to be more sensitive to criticism from their parents than their healthy peers are.

How can we safeguard children’s rights in conflict zones? The winners of the 2025 Children’s Rights Moot Court Competition, team 19 from O.P. Jindal Global University in India, show unique potential to bring about positive change in this area.

Ijeoma Uchegbu is Professor of Pharmacy at University College London (UCL). As a female scientist of colour, she was initially reluctant to play an active role in the university’s diversity policy. Until, that is, she had a radical change of heart: ‘I knew it; I had to become an evangelist.'