Multiple stars, that is two or more stars composing a gravitationally bound system, are common in the universe.

In the past decade many population studies have been performed with the Atacama Large Millimeter/submillimeter Array (ALMA) to understand the bulk properties of protoplanetary disks around young stars. These population studies mostly consisted of low mass stars, with relatively few of the disks around…

Promotores: Prof.dr. J. Schaye, Prof.dr. S.D.M. White (MPA Garching)

Promotor: J. Schaye

Promotor: R. Verpoorte, Co-promotores: Y.H.Choi, N.R. Mustafa

The focus of this thesis is how stars like our Sun and planets like Jupiter, Saturn, and Earth are formed.

Promotor: Prof.dr. E. F. van Dishoeck

High-angular-resolution observations of the circumstellar material have uncovered numerous and very diverse substructures in protoplanetary discs, raising the question of whether they are caused by forming planets or other mechanisms.

Galaxies form and evolve through close interaction with their surroundings. As a result, the heavy elements ('metals') that are synthesized in stars, are found both inside and outside galaxies.

Within the field of astronomy, understanding how galaxies grow and evolve from the Big Bang to the present day is a challenging and complex question.

Promotores: Prof.dr. W.J.G.M. Peijnenburg & Dr. M.G. Vijver

Wetenschappers bij de Leidse Sterrewacht onderzoeken de oorsprong van sterren en hun planetenstelsels. Ze detecteren en karakteriseren planeten rondom andere sterren (exoplaneten). Ze onderzoeken hoe sterren en planeten ontstaan. En ze volgen moleculen van interstellaire wolken tot planetenstelsels…

What is the effect of light at night on plant phenology and physiology, and how does this affect plant interactions with other species?

The studies described in this thesis deal with glycosidases, in particular alpha-galactosidases.

Promotor: C.A.M.J.J. van den Hondel, Co-promotor: Sandra de Weert

This thesis discusses the physical and chemical processes than influence the composition of forming planets.

This thesis investigates how galaxies form and what diversifies the evolutionary histories of galaxies.

The formation of stars and planets happens over multiple scales, which can interact. In particular, planet formation happens in the dense, complex environment of star forming regions.

One of the key quests in astronomy is to study the growth and evolution of galaxies across cosmic time. Radio observations provide a powerful means of studying the formation of stars and subsequent buildup of distant galaxies, in a way that is unbiased by the presence of dust.

To address the fundamental questions of how life on Earth emerged and how common life may be in the Universe, it is crucial to know the chemical composition of the planet-forming material.

Promotor: Prof.dr. E.F. van Dishoeck, Prof.dr. F.F.S. van der Tak (RUG)

Plants produce an astonishing variety of secondary metabolites (SMs) which are thought to play vital roles in the fitness of plants through ecological interactions.

Promotor: G.P. van Wezel

Promotor: Prof.dr. E.F. van Dishoeck

The soil ecosystem consists of the largest reservoir of biodiversity on Earth.

Promotor: E.F. Smets, Co-promotor: T.R. van Andel

The solar system was formed approximately 4.56 billion years ago. Despite the numerous theories that have been developed over the years, the formation and evolution of the solar system still remain unclear.

This thesis investigates the relations between metabolism and anatomy through the use of Magnetic Resonance Imaging (MRI).

Promotores: Prof.dr. M. Franx, Prof.dr. P.G. van Dokkum (Yale University)

Promotor: Prof.dr. L.J. Slikkerveer

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

A dense region of a gaseous and dusty cloud collapses to form a protostar surrounded by a disk and an envelope. This thesis uses both observations and models to study physical and chemical conditions of these protostellar systems which are likely where planets start to form.

Promotor: Prof.dr. H.V.J. Linnartz

Promotor: Roeland M.H. Merks

Huub de Groot

Promotores: Prof.dr. T.H.W. Bäck, Prof.dr. M. Bongards (Cologne University)

It has been a long-standing mystery how complex biological structures emerge from such seemingly uncoordinated building blocks as cells and tissues, in the presence of only minimal environmental guidance.

What are trait-trait relationships in wetlands? To what extent the so-called leaf economics traits deviate from terrestrial ecosystems? How traits specific to wetland plant relate to plant strategies? What’s the relationship between wetland plant traits to the ecosystem functioning (e.g. productivity,…

Protein–protein complexes are formed via transient states called encounter complexes that greatly influence the formation of the stereospecific complex.

Large areas of space are filled by molecular clouds that consist of gas and dust grains that are the remnants of dead stars. When these clouds start collapsing, the decreasing temperature and increasing density cause gas particles to start accreting onto dust grain surfaces.

Sobral

The origin and evolution of galaxies are closely tied to the cyclic feedback processes between stars and the interstellar medium (ISM).

Detecting planets during their formation stages is crucial for understanding the history and diversity of fully developed planetary systems like our own. However, observing young planets directly is challenging because they are often deeply embedded within their host protoplanetary discs, rich in gas…

My PhD thesis investigates the ecological significance of resistance against drought-induced air bubble formation inside the water conduits of plants (embolism), and the plasticity and functional aspects of stem anatomical traits in woody and herbaceous species.

The name ‘Jambi flora’ refers to fossil plants found as part of a rock formation from the Early Permian (296 million years old), located in the Jambi Province of Sumatra, Indonesia.

Protoplanetary disks are the gas and dust environments where planetary systems form around young stars. Using observations from the Atacama Large Millimeter/submillimeter Array (ALMA) this thesis analyses the gaseous molecular reservoir, using multiple tracers to resolve the 3D structure of protoplanetary…

Diverse types of exoplanets such as gas giants on close-in orbits (hot Jupiters) and young massive giants on wide orbits (super Jupiters), with no analogs in the Solar System, pose challenges but also opportunities to our understanding of planet formation and evolution.

Promotor: Prof.dr. E.F. van Dishoeck, Co-Promotor: G.J. Herczeg

Even though more than 4000 extra-solar planets are known today, only a small fraction of these has been captured in an image. To better understand the planet formation mechanisms in solar-like environments we started the Young Suns Exoplanet Survey (YSES).

The plant hormone auxin plays a central role in the growth and development of plants. Auxin acts in a concentration dependent manner and polar cell-to-cell transport of this hormone determines its distribution in the tissues of plants. This polar auxin transport is mediated by several families of auxin…