A group of astronomers led by Leiden PhD student Sebastian Zieba has discovered using the James Webb Space Telescope (JWST) that the rocky exoplanet TRAPPIST-1 c has a thin atmosphere. Although the planet is nearly identical to Venus in size and temperature, and was expected to have a thick atmosphere,…

Theft, prostitution, fortune-telling or murder. Historian Manon van der Heijden and a group of students are researching court records from The Hague from 1600 to 1800. They are tracing crimes and offenders and shedding new light on The Hague’s Gevangenpoort (or Prison Gate). Among their many discoveries…

How do animals choose their partners? The answer is simple: it’s all about quality. While humans tend to wear clothes that happen to be in fashion, animals do nothing without a reason. Behind beautiful plumage or a deafening roar is only one message: I am in great shape. The evolutionary courtship displays…

Universele Verklaring voor de Rechten van de Mens en het Genocide verdrag, 75 jaar Oekraine

Roderick Bouman is collection manager of the Leiden Hortus botanicus. He keeps track of which plants there are in the garden, where they come from and makes sure visitors can find the right information about them. ‘We are like a regular museum,’ says Bouman. ‘Except that our objects are alive. That…

In July 2022 our alumnus Samatar Botan received the news that he had received the NWO Mosaic 2.0 grant. This grant enables him to start a PhD research at our Faculty on the ancient Aksumite Empire, a topic that is close to his heart. We speak with him about his ambitions and drive. ‘I want to know more…

It is a familiar phenomenon: you ask the assistant on your phone to call your mother, but it calls a friend instead. Tom Kouwenhoven, PhD student in the SAILS programme, investigates how humans and Artificial Intelligence (AI) can better communicate with each other, so that these kinds of situations…

It’s not something the police force wants to see, but it still occurs: racist and misogynist police conduct. Human rights specialist Dr Linda Louis has studied how technology could help police officers behave correctly and comply with the applicable legal norms.

Not passed your Dutch exam? Then there’s no HAVO (Higher General Secondary) or VWO (pre-university) diploma for you, says the Inspectorate of Education's Inspector General. This comment fuels a discussion on an exam that is already under fire. The final exam for Dutch is said to be uninspiring, too…

Moderne oorlogsvoering kent geen grenzen. Dreigingen zijn steeds vaker digitaal. Promovendus Annelies van Vark stelt dat Scandinavië beter voorbereid is op gevaar. Zij pleit voor een sterkere rol van de krijgsmacht, herinvoering van de dienstplicht en paraatheid – óók bij burgers.

In a supplementary decision on 17 May 2022, the Executive Board of Leiden University has concluded that it will publish the titles of seven articles in which there is evidence of malpractice. This concerns a former staff member of the Institute of Psychology. The Executive Board considers it to be in…

Are magnetic fields older than the first light? And how did they influence the development of our universe right after the Big Bang? Cosmologists from Leiden, Groningen, and Utrecht are now collaborating to investigate this.

Studenten onderzochten maatschappelijke vraagstukken voor het project Leren met de Stad en presenteerden hun resultaten tijdens een informatiemarkt.

Only one in five young people with emotional health problems such as an anxiety disorder receives appropriate professional help. GPs often fail to properly recognise the signals in children and young people, according to psychologist Semiha Aydin. How can we improve this? PhD defence 23 February.

The Phase 3 clinical trial results of the promising Covid-19 vaccine of Johnson & Johnson are expected this month. The Dutch electron microscopy facility NeCEN helped develop the company’s vaccine, and they have now published their scientific findings in Nature Communications.

Food security touches upon human rights, international law and sustainable development. These frameworks are not separate worlds but deeply interconnected; something that becomes painfully clear in times of climate crisis, armed conflict and inequality.

For the first time, an international group of astronomers have seen the heat glow of two ice giant planets colliding. They could also observe the resultant dust cloud move in front of the parent star several years later. Led by Leiden astronomer Matthew Kenworthy, they monitored the star's brightness…

At the start of his PhD, intelligence analyst William Lippert didn’t yet know what to expect. Little had been written on the subject. Three years later, he is sure: conventional arms control agreements promote peace.

Joey Zuijdervelt

Dialysis patients experience a range of physical and mental symptoms that interact and influence each otherIn her doctoral research, psychologist Judith Tommel wanted to find the optimum approach to help these dialysis patients improve their quality of life. ‘We need to make sure we avoid excluding…

Graduating in international law and fulfilling a childhood dream by performing your own theatre show. Alumna Fleur Verhoeff has achieved both. How did she go from studying law to the performing arts? And how does her background in international law help?

An international team of astronomers, including Leiden PhD student Elia Pizzati, has observed several ancient quasars that, surprisingly, appear to be floating alone in the early universe (less than a billion years after the Big Bang). Until now, astronomers, based on models, assumed that quasars are…

Astronomers have captured a new deep field of Pandora's Cluster (Abell 2744) with the James Webb Space Telescope. The images show never-before-seen details. The results are described in four scientific papers. Leiden astronomers Marijn Franx and Mariska Kriek collaborated on the study. 'This opens a…

People suffer from anxiety wait on average twelve years before seeking professional help. That’s a pity and it’s unnecessary, says development psychologist Leonie Vreeke. She is therefore developing prevention programmes where parents learn to react in a helpful way to anxious behaviour on the part…

Astronomers led by Leiden PhD candidate Richelle van Capelleveen have, for the first time, discovered an exoplanet that has carved a bright gap in the protoplanetary disc around its star. This rare observation provides new insights into how young planets shape their surroundings.

Organisation

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.

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…

The war in Ukraine is leading not only to human suffering. Ukraine's cultural heritage is also experiencing the consequences of the war: museums are being bombed and 'Russification' in the occupied territories means children no longer learn Ukrainian. Researcher Evelien Campfens was commissioned by…

Just a stone’s throw from Binnenhof, the heart of Dutch politics, Spui Campus will open its doors in early 2026. Join us for a sneak preview.

Florian Herrendorf has won the Fruin Prize 2023. His thesis was chosen out of 11 nominees as the best master's thesis in history studies.

Sixteen master’s students from a variety of disciplines are helping The Hague Police to find new clues in a cold case.

What exactly does it mean when your doctor says you have a ‘good chance’ of survival? Leiden researchers discovered that there is a big difference in how people interpret such probability phrases. And that can be a problem, warns lead researcher Sanne Willems in her blog post.

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.

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…

Just like the professional riders from the Jumbo-Visma team, amateur cyclists will soon be able to analyse and improve their performance. Leiden data scientists working with the cycling team are making their smart data model available so that every serious cyclist can keep track of their fitness.

How can we improve the treatment of thrombosis, reduce the disease’s impact and spend less money while we’re at it? This is what Erik Klok, Professor of Internal Medicine and an internist, is researching. He will discuss it in depth in his inaugural lecture on 10 March.

Studying surfaces of solid materials: it may not seem relevant to energy consumption, but it is. Marcel Rost studies how platinum electrodes wear out. Those electrodes are a crucial component in the fuel cells of hydrogen-powered cars. ‘We need to make the switch from fossil fuel energy to hydrogen.…

Rainbow flags, funky sounds and drag queen Petty Libel: the very first Canal Pride Leiden has become reality. Leiden University joined the parade with a packed and buzzing boat. ‘The Leideners were really supportive and gave us a great response.’

Building more in urban areas is, in most places in the Netherlands, the smartest way to tackle the housing crisis. This is evident from research conducted by Janneke van Oorschot, published in a partner journal of Nature. Remarkably, this does not have to come at the expense of green spaces in cities.…

Organs and tissues grown in the lab may in the future be able to cure people with organ failures. Micha Drukker, professor of Stem Cells, Developmental Biology and Technology for Innovative Drug Research, is convinced that the use of stem cells will make this possible. He will deliver his inaugural…

Symposium

Conference

Lecture, European Union Seminar

Lecture, LUCIS What's New?! Series

Ambroise Paré, Thomas Sydenham and Herman Boerhaave: all were great medical innovators in their time. We know far less about the 19th-century Russian physician and scientist Nikolay Ivanovich Pirogov. PhD candidate Inge Hendriks researched him in Dutch and Russian archives and collections. She discovered…

Hak, lawyer, international imagery law lecturer, and adjunct associate professor, talks about his PhD research on the use of images in international criminal prosecutions. He was a public prosecutor in Canada for over 30 years and dealt primarily with the prosecution of homicides and other major cri…

Op dinsdag 10 januari 2022 zijn tijdens de facultaire nieuwjaarsreceptie de jaarlijkse Meijersprijzen en de scriptieprijzen uitgereikt.

Each year, around forty women in the Netherlands lose their lives, most often at the hands of a (former) partner or family member. Judges, lawyers and survivors now turn directly to Professor Marieke Liem for expertise. For her, this is telling: ‘The time has come for greater knowledge and a coordinated…

Alumnus Jelte Liemburg, aged 29, aims to visit every single one of the 500 museums in the Netherlands that take part in the national museum pass scheme.