Promotor: Prof.dr. P.C. van Welzen

What does the daily life of those who travelled to Syria to join jihadist groups look like? Destination Syria, a new ISGA report, provides answers to this question

Research on Inclusiveness and Diversity at the Faculty of Science at Leiden University

Promotor: P.G.L. Klinkhamer, Co-Promotores: K. Vrieling, P.P.J. Mulder

Plants and their pollinators form complex interaction networks. Within these networks, species differ widely in the number of species they interact with.

This thesis describes the role of pollution, specifically neonicotinoid insecticides, as an actor of the ongoing biodiversity decline.

Pre-modern long-distance trade was fraught with risks which often created conflicts of interest. The ensuing disputes and the ways the actors involved dealt with them belong to the field of conflict management.

Organic amendments applied to agricultural fields can partially offset our carbon emissions to the atmosphere and improve the resilience of agriculture to the effects of climate change. Driving these benefits, however, are complex and poorly understood interactions between organic amendment properties,…

As a non-invasive genetic method, eDNA based approaches have become an important component of ecologists' and environmental managers' toolkits for biomonitoring in conservation and an increasingly important source of ecological knowledge.

This thesis pioneers diatom molecular identification and quantification through genome-scale methods, with four key aims: (i) reviewing DNA/RNA sequencing methods in aquatic biomonitoring to highlight their strengths and limitations;

On 10 February 2022, Christian Mommers defended the thesis 'Voluntary return and the limits of individual responsibility in the EU Returns Directive'. The doctoral research was supervised by Prof. P.R. Rodrigues and Prof. P. Boeles.

Migration and Mobility in the Early Roman Empire by Luuk de Ligt and Laurens E. Tacoma (Eds.)

Biodiversity and trade: mitigating the impacts of non-food biomass global supply chains.

The recently introduced nature-originated deep eutectic solvents, so-called natural deep eutectic solvents (NADES) are considered as truly green solvents, which composed of natural ingredients found abundantly in organisms.

The Excellence of the Arabs is a spirited defense of Arab identity—its merits, values, and origins—at a time of political unrest and fragmentation, written by one of the most important scholars of the early Abbasid era.

The Genius of Invective is a peerless example of the breadth, depth, and complexity of the Arabic classical literary tradition. It was once one of the most popular works of Arabic literature, read across all regions from Mauritania to India, from Istanbul to Zanzibar. This volume marks the first English–Arabic…

In this thesis, deep learning is studied from a statistical perspective. Convergence rates for the worst case risk bounds of neural network estimators are obtained in the classification, density estimation and linear regression model.

In this thesis integral points on affine del Pezzo surfaces are studied.

Pectin is a plant cell wall polysaccharide made of mainly D-galacturonic acid (GA) subunits. The potency of the filamentous fungus Aspergillus niger to naturally secrete high amounts of pectinases to degrade pectin has been utilized for the industrial production of pectinases.

The delegation from Leiden University Medical Center, led by Dean Marlies Reinders, visited Surabaya, Makassar, and Jakarta in October 2025 to explore opportunities for research and academic cooperation. This visit marks an important step in strengthening international ties and fostering long-term collaboration…

In this research we have studied how teaching graphing formulas by hand (i.e. sketching a graph of a formula) could promote grade 11- and 12-students’ symbol sense.

This is an incomplete list of scientific publications by students and staff of the Creative Intelligence & Technology MSc programme.

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…

Professor Sarah de Rijcke will become the new Rector Magnificus on the Executive Board of Leiden University on 15 January 2026. She will succeed Professor Hester Bijl, who will become Rector Magnificus at Delft University of Technology.

The Executive Board has adopted a new Code of Conduct on Integrity for staff. This new code encompasses all the existing regulations within Leiden University, including in the field of research, behaviour towards students and purchasing. 'This Code of Conduct is a very clear statement,' commented Rector…

Lecture, Comparative Indo-European Linguistics (CIEL) Seminars

At a symposium on 26 May, experts, staff and students from Leiden University will discuss what should happen with Rein Dool’s painting in the Academy Building and what the guidelines for the University’s exhibition policy should be. These issues will be explored from diverse perspectives during the…

Should Leiden University cut its ties with the fossil fuel industry forthwith? This was the main question in a debate between students and staff. The answer was clearer for some than for others.

Stichting Migratierecht Nederland and the Europa Institute of Leiden University are jointly organising the conference ‘Children’s Rights and Migration’ that will take place in Leiden on 26 January 2023. Researchers, lawyers, judges, policy makers and other professionals from migration legal practice…

The Leiden-Delft-Erasmus Universities strategic alliance celebrates its tenth anniversary in 2022. At the ‘The Next Ten Years’ anniversary celebration in the Faculty Club on 12 April, the partners looked back on their achievements and ahead to the major social challenges of the next ten years.

As of 1 November 2025, Professor Luc Sels will assume the role of President of Leiden University’s Executive Board.

Research into our history of colonialism and slavery, heart-to-heart conversations at a Keti Koti table, exhibitions, lectures and podcasts that establish the link between present and past. Staff and students participated in the national Slavery Memorial Year in many different ways. What have we learned…

At the start of 2020, the book ‘Safeguarding Children’s Rights in Immigration Law’ was published by Intersentia.

During a meeting at the University on 10 November, staff spontaneously removed a painting by artist Rein Dool from the wall in one of the meeting rooms in the Academy Building, reversed it and placed it on the floor. A tongue-in-cheek action with a serious undertone. This has led to a lot of commotion…

Martijn Ridderbos has been reappointed vice-chairman of the Executive Board of Leiden University by the Board of Governors.

Leiden University regularly confers honorary doctorates, and presents awards and prizes.