Annetje Ottow is the first female president of the Executive Board of Leiden University, which means a return to her Alma mater.

When the tokay gecko loses its tail, a new one grows from resident stem cells at the stump. Each tissue type - muscle, bone, blood vessels and skin - develops from specific stem cells. This discovery by Luthfi Nurhidayat holds potential implications for advancing regenerative medicine in humans. Nurhidayat…

With a self-converted red camper van, biologists and twin brothers Kevin and Marvin Groen go on a nature adventure in Eastern Europe. Together, they search for wild animals, beautiful nature and places to sport. From a long search for a bear in the Slovakian wilderness to the discovery that pelicans…

When do we define a piece of nature in the city as a park? And when is something a tree or shrub? It may seem obvious, but in scientific literature the definitions vary quite a bit. That makes comparisons difficult. Environmental scientist Joeri Morpurgo looked at the differences and designed a general…

Cotton is the most widely used natural fibre for clothes. But how polluting are our jeans and shirts actually? Environmental scientist Laura Scherer coordinated an international research project on the impacts of cotton. ‘The purchases of consumers in Europe can contribute to water scarcity in China…

A huge shiny aluminium object stands in the middle of the Polderlab in Oud Ade. Are the researchers trying to make contact with extraterrestrial life? Certainly not; they are using the ’Moon landers’ to measure whether innovative forms of agriculture reduce greenhouse gas emissions. Fleur van Duin works…

Connecting worlds, enhancing research and teaching, and providing innovative solutions to complex social issues: that is the idea behind interdisciplinary research. In that respect, a huge amount happened at Leiden University in 2023.

Leiden University is celebrating its 450th anniversary in 2025 with a feast for the eyes, ears and spirit. The anniversary year opens with an extra special Dies Natalis on 7 February. Highlights includes an alumni festival, three exhibitions and a canal concert.

Neanderthals were able to outwit straight-tusked elephants, the largest land mammals of the past few million years. Leiden professor Wil Roebroeks has published an article about this together with his German colleague Sabine Gaudzinski-Windheuser in the Science Advances journal.

Bacteria carry countless hidden treasures in their DNA: fragments that could hold the key to new medicines. But how do you pick out the most promising ones from millions of options? ‘Look at the switches that turn genes on and off,’ says molecular biologist Gilles van Wezel.

Martina Vijver has been nominated as Teacher of the Year of the Faculty of Science. She gets this nomination for the course Ecotoxicology she taught in 2022. The 52 students who took the course were hugely enthusiastic, as can be read in their positive reviews. What is so great about this course then?…

Leiden PhD candidate Mona Shahab climbed Mount Everest two years ago to raise money for the education of disadvantaged children in Egypt. She made it to the top and posed there with the University flag. She recently presented the flag to Rector Carel Stolker.

The Vrouw Vennepolder near Oud Ade has been transformed into the Polderlab. Scientists and students from Leiden University, together with farmers and citizens, investigate how to manage peatland in a sustainable and profitable manner. A great opportunity for students to experience how scientific knowledge…

From a vegan community kitchen to a green framework for drug development: sustainability became more visible in everyday campus life at Leiden University in 2025.

The Dutch Research Council (NWO) has awarded Vidi grants to Leiden researchers.

Leiden biologists have found a mutation in flour beetles that allows them to speed up their development. The study has been published in Nature Ecology and Evolution.

Pesticides can form a toxic cocktail when they occur in combination in surface water. This is the finding of research that Leiden University and the Dutch National Institute for Public Health and the Environment (RIVM) presented on Monday 14 October. The Dutch Ministry of Infrastructure and Water Management…

As the father of a family with four children, he already visited the Hortus regularly. Now Tom Schreuder also comes there for his work. Every day he travels from Lisse by bike. The new Director Operations calls it a ‘perfect match’.

A bacterium hiding from the immune system and picking up bits of DNA from its environment. The result: gaining new traits, such as better protection against antibiotics. Fortunately, we have not found such a damning scenario yet. However, PhD student Renée Kapteijn did find the first clues, which…

Within the same species of butterfly many different wing patterns can occur. How is this possible? According to researchers Ben Wielstra and Emma Berdan, of the Institute of Biology Leiden (IBL), the answer lies within supergenes. A supergene is a part of a chromosome that contains many strongly linked…

Green spaces boost mental health—especially in busy cities. A new study from Leiden and Stanford University reveals how nature benefits urban well-being and offers low-cost ways to make city life healthier for everyone.

The pesticide thiacloprid turns out to be more harmful than previously thought. It can disrupt the lives of freshwater invertebrates and their communities, upsetting the balance and functioning of entire freshwater ecosystems. This was shown by ecologist Henrik Barmentlo and colleagues, their research…

How can we make our cities greener and more people-friendly? Two Campus The Hague projects have secured a grant from the Municipality of The Hague. The researchers and students from both projects are working with city residents to find sustainable solutions to local issues.

Some thirty Leiden students balanced on SUP boards for the Supping for Sustainability Lustrum activity. Together with alumnus Merijn Tinga, better known as the Plastic Soup Surfer, they paddled their boards through the Leiden canals and waterways, fishing plastic waste out of the water.

With the appointment of Dennis Janssen as operational director at the end of last year, the management team at the Observatory is now complete. Janssen has been working at the university for over twenty years, but the faculty and the Observatory are new to him.

The year 2023 saw the earthquake in Turkey and Syria, the Wagner Group rebellion and wildfires and floods as all the weather records were smashed. Our most-read stories were about the climate crisis and the elections: here’s the list.

Should we be growing rice and building materials instead of grass for cows? From invasive crayfish to cultural heritage and groundwater levels: ten graduating students explored the future of the Groene Hart, the rural region just outside the cities of Delft, Rotterdam and Leiden where they study.

From sponsored runs to festivals and from open days to concerts: Leiden University hosts lots of events each year. We are highlighting six of them for 2023.

Sinds vorig jaar staan er gekleurde pilaren op de universiteitscampus. Met deze ‘Act of Kindness Pillars’ wordt eenzaamheid bij studenten tegengegaan.

Professor of Fungal Genetics and Biotechnology Arthur Ram explains how fungi can help us be more sustainable.

More CO2 in the atmosphere is making food crops more calorific, less nutritious and potentially more toxic.

From telescopes to science fiction: in just one semester, students with no background in physics or astronomy get to explore the universe. The first group of students started last month in the new minor Our Universe.

A new graphene-based method could make for faster, cheaper and more accurate DNA sequencing, say a group of Leiden physicists and chemists.

For her bachelor’s thesis, Molecular Science and Technology student Madouc Bergers synthesized her own molecule that can inhibit the breakdown of sugars. Although most students do not even manage to make one building block, Madouc made three. Partly because of this, she has been nominated for the Science…

Two research groups involving Leiden University have been awarded a major European grant, the ERC Synergy Grant. This for research on the development of membranes that can clean water and purify medical drugs and research on the biological clock in certain bacteria.

In his leaving interview, Martijn Ridderbos doesn’t have to think long when asked what he is most proud of. ‘Bringing people together; creating things together. Reducing the gap between researchers and the staff who support them because the latter are essential. We’ve achieved that and the seeds have…

Although there is considerable evidence that nature in the city is beneficial to both people and animals, we still do not have an overall picture of those benefits. To rectify that, a Leiden PhD candidate and a student – armed with a cargo bike – are using The Hague as a life-size laboratory.

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…

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…

Gianne Derks is the MI’s new scientific director from 1 May. She has worked abroad longer than in the Netherlands and, after more than 27 years in Surrey, she dreams in English. Who is this new director and who or what managed to entice her to make the move to Leiden?

Biologist Marcel Schaaf is one of four science faculty members who achieved the Senior Teaching Qualification in Leiden last year. How was that and what drives him? ‘Students receive way too often feedback that they cannot put into practice.’

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.

A true shower of awards for students from the Faculty of Science during the annual KHMW Young Talent Awards ceremony. On Monday, 25 November, no less than nine first-year students received a prize for the best academic results in their first year. In addition, there were graduation prizes for master’s…

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.

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.