A complex community of microbes develops in the infant gut shortly after birth. We call this community the infant gut microbiota. The microbiota influences the health of the infant, which makes the composition and function of the infant gut microbiota an important topic to study.

The project seeks to explore the interplay of valuation and inequalities in science, using the interdisciplinary and planet-critical field of forest research as empirical case. It examines which/whose knowledge is recognised on what grounds, and how social dimensions like gender and geographical location…

For each living organism health is ensured by correct functioning of its cells. Cells therefore have elaborate methods for regulation of their proteins.

To what extent does using 360 immersion to a speaking task change the elicited speech, compared to conditions with 2D presentations?

Water droplets float in a hot pan because of the so-called Leidenfrost effect. Now physicists have discovered a variation: the Elastic Leidenfrost effect. It explains why hydrogel balls jump around on a hot plate making high pitched sounds. Publication in Nature Physics on July 24.

In a virtual game environment, one of the positive effects of anonymity is the absence of one's prejudice toward others, which can give a person the freedom to change and experiment (Bartle, 2003). This project will adopt anonymity to be added to online cross-cultural collaborative learning in higher…

‘Everyone’s talking about it, everyone thinks everyone else is doing it, but the reality is disappointing,’ says biochemist Gerard van Westen in his 3 October University lecture in the Van der Werfpark. In the full marquee, he gets a laugh with this suggestion that artificial intelligence is comparable…

STM scanning experiments on poorly conducting materials are challenging, and can cause a distortion effect. A new model corrects for this effect, allowing physicists to better study materials in their quest to understand unconventional superconductivity. Publication in Physical Review B as Editor’s…

The precise psychobiological mechanisms leading to chronic physiological stress responses have not been sufficiently explained, although stress is a major risk factor for disease and early death. A problem for conventional stress theory is that most of these responses seem to occur in situations without…

If a new method has been developed to recognize and treat a (neuro-)psychological disorder or related behavioral factors, it cannot yet be used directly in clinical practice. First, the method should be evaluated, preferably in randomized controlled trials.

Plastic pollution is a major environmental issue. Although regulation is being adopted, plastic pollution is still increasing. Effective and strict enforcement is key and NGOs and civilians can be instrumental in this.

In meta-analysis, heterogeneity often exists between studies. In such cases, it is essential to investigate the sources of heterogeneity and understand the relationship between effect size and study characteristics (i.e., moderators).

This year, Leiden University celebrates its 444th birthday – and when you’re giving a party, you need great music! Neuropsychologist Rebecca Schaefer agrees. She has been fascinated by music since she was a child, and now she studies how music can make us happy, give us energy or calm us down.

The aims of the project are to: further clarify 'inhibition by safety'; explore and describe all possible sagety factors, with a special focus on the primary human safety source: social connectedness; reviewing prolonged stress responses without stressors.

PhD candidate Dennis Wander searches for the best of both worlds. That is to say: a cancer drug that is effective and also has minimal side effects. To this end, he makes new molecules inspired by two existing medicines. And not without result: ‘We have created a new variant that is very promising.’…

This thesis has shed light on some of the ways in which the local electrolyte composition can differ from the bulk and how these changes in the local reaction environment can determine the activity and/or selectivity of two important electrocatalytic reactions, namely, electrochemical CO2 reduction…

According to the LUMC, patients experience 30% fewer serious side effects when medication doses are tailored to their DNA.

On 20 October 2021 Michael Ramsden defended the thesis 'The Role of the United Nations General Assembly in Advancing Accountability for Atrocity Crimes: Legal Powers and Effects'. The doctoral research was supervised by Prof. N.M. Blokker.

This article examines leadership encouragement and psychological safety as antecedents of prosocial rule-breaking (PSRB) behaviour.

This thesis focusses on the temperature structure in protoplanetary disks. The relation between structures seen in the dust and gas-phase molecules is investigated.

Tuberculosis (TB) is a major global health problem caused by the bacterium Mycobacterium tuberculosis (Mtb). In 2015, there were estimated to be 10.4 million new cases and 1.8 million deaths ascribed to TB, making it one of the top 10 causes of death worldwide. Unfortunately, the only current registered…

In this thesis I examine how soil biotic and abiotic characteristics change and interact throughout the course of afforestation and how they subsequently impact tree performance.

More collaboration, combining data and asking the right questions. These are a few of the recommendations that policymakers and researchers formulated at the conference 'Data gedreven Beleidsontwikkeling' on 28 November 2017.

Optimization, mechanisms of action and predictors of the outcome of light therapy in depression: A multicenter randomized trial

Our ability to learn and control movements is essential for engaging in goal-directed behaviour. From buttoning your shirt and driving a car, to cooking dinner and brushing your teeth -- our actions in daily life rely on this ability.

Music can affect how we feel, think, and behave. But how do we learn about the specifics of people's responses to music so that we can apply this to health and well-being? By looking at characteristics of the music, as well as the differences between listeners, we hope to better understand as well as…

One of the most crucial aspects of our behaviour is our motivation to explore novel environments and interact with new people. This became painfully clear during the COVID-19 lockdowns, when many people suffered from lack of new experiences and real-life social interactions. The relevance of novelty…

The Russian threat to Europe, pro-Palestine protests, the passing of psychologist Andrea Evers and speculations on extraterrestrial life. These were among our most popular articles of the year.

First author Scott Waitukaitis and principal investigator Martin van Hecke have made the cover of Nature Physics with their publication on a newly discovered effect. The Elastic Leidenfrost effect explains why hydrogel balls jump around on a hot plate making high pitched sounds.

In their article; The Effects of Legal Measures to Empower Supervisory Directors: Evidence from a Financial Distress Perspective, Santen and De Bos discuss the relationship between the corporate governance structure of a company and its financial performance. Until now studies predominantly hypothesize…

Promotor: A. Achúcarro, Co-promotor: A. Boyarsky

A coronavirus booster shot provides a better immune response against COVID-19 than a single vaccine dose. mRNA boosters are the most effective upon receiving Janssen. These are the results of a collaborative study between several organisations, including the Leiden University Medical Center (LUMC).…

It is with deep sorrow that we share the news that our dear colleague Andrea Evers passed away on Monday, 4 August 2025. Since 2013, Andrea had been affiliated with the Faculty of Social and Behavioural Sciences at Leiden University as Professor of Health Psychology. She was an undeniable driving force…

Rare-earth materials are prime candidates for storing quantum information, because the undesirable interaction with their environment is extremely weak. Consequently however, this lack of interaction implies a very small response to light, making it hard to read and write data. Leiden physicists have…

The latest research from the Leiden outdoor laboratory ‘Living Lab’ shows that the insecticide thiacloprid strongly influences even the most common and robust dragonfly species in the Netherlands. The study was published in the Journal of Applied Ecology.

How do people acquire language? How can you train your brain? What is the effect of stress on an unborn child? LIBC research topics range from language processing to cognitive robotics, and from psychiatric disorders to the impact of social factors on human behaviour. Meet several main research topics…

Human measures to protect lions have an impact on the genetic health of populations. Leiden and Kenyan scientists discovered this by analysing the DNA of 171 Kenyan lions. ‘By fencing reserves, for example, the chance of inbreeding increases.’ With the knowledge and tools from the research, management…

One of the objections to the Comprehensive Economic and Trade Agreement between Canada and Europe (Ceta) is that countries would be surrendering national sovereignty to multinationals which will obstruct effective climate policy. But compared to other trade agreements, CETA is an improvement.

A discovery made in Leiden helps not only to make natural gas from CO2 but also to store renewable energy. Research by Professor Marc Koper and PhD student Jing Shen shows how this process can be implemented in a cost-effective and controllable way. Nature Communications, 2 september 2015.

Following the Mangold and Kücükdeveci case law of the CJEU, the horizontal direct effect of EU general principles and of provisions of the Charter of Fundamental Rights became a hotly debated issue.

Advanced sensing techniques require graphene with high quality and well-controlled surface chemistry.

A new therapy for the serious Graft-versus-Host disease

The aim of this study is to identify the side effects during treatment with methylphenidate and to investigate how children experience the use of the medication (such as Ritalin, Concerta and Medikinet).

Discovering effective new drugs is a long, expensive and uncertain process. Laura Heitman wants to improve this by finding out more about how drugs bind to proteins that play a role in disease. She calls it ‘drug discovery 3.0’. Inaugural lecture on 9 December.

Patients on patient forums share all sorts of things about their illness: from side effects and advice to messages of support. PhD candidate Anne Dirkson uses artificial intelligence (AI) to retrieve this information. ‘Ninety per cent of the side effects weren’t officially registered.’