Internships Faculty of Science KU Leuven

1. Internships Faculty of ScienceKU Leuven Leuven, Belgium sc.kuleuven.be We invite motivated and talented undergraduate (Bachelor) and Masterstudents, interested in an international research experience at KU Leuven’s science departments, to apply for an internship. Applicants are required to submit: • a one page CV (resume) • a one page motivation letter, including a short statement of personal research interests • 2 letters of recommendation Duration: min. 3 – max. 6 months Financial support: stipend or self-supporting Deadline for application: 20th of January 2017 More information about the research internships topics can be found below

2. Internshipssc.kuleuven.be/internships Detailed descriptions of the research internships topics can be found below

3. ri 1Coulomb excitation measurements and radiation detector developments Coulomb excitation and decay spectroscopy are key experimental tools to deduce nuclear observables like transition matrix elements, energy levels and radioactive decay half lives. These observables are benchmarks to validate nuclear theory and to give insight in the strong force at work in the atomic nucleus. At the ISOLDE radioactive beam facility at CERN (Switzerland) a new accelerator has been commissioned for the acceleration of short-lived radioactive ion beams. These beams are used for Coulomb excitation experiments; in-elastic scattering experiments whereby the atoms are excited to higher lying energy states. The emitted radiation after de-excitation is detected with an array of high purity germanium semi-conductor detectors. This so-called Miniball detector is shown in its position at the ISOLDE facility. Radiation detectors used for the experiments at CERN are tested, characterized and upgrade at the detector laboratory at KU Leuven. As a trainee you will be involved in this work and, depending on the beam time schedule at CERN, you will participate in an experimental campaign at ISOLDE. At the end of the internship an oral presentation of the work performed is mandatory. applicant’s Current Degree program (preferred): Master in Physics or Master in Engineering majoring in physics or nanoscience and nanotechnology Responsible scientist(s): Prof. Piet Van Duppen, Prof. Mark Huyse Duration: between 3 and 6 months Stipend: yes

4. ri 2In-gas jet laser ionization spectroscopy Laser spectroscopy is a key experimental tool to deduce nuclear observables like charge radii, magnetic dipole and quadrupole moments and nuclear spins. These observable are benchmarks to validate nuclear theory and to give insight in the strong force at work in the atomic nucleus. A new project to develop this technique for the heaviest elements of Medeljev’s table has been initiated at KU Leuven through funds from the European Research Council (ERC). The approach is based in-gas jet laser ionization spectroscopy and a new laser and mass separator laboratory has recently been commissioned. The characteristics of the laser ionization schemes for different elements, gas-jet formation and ion transport systems are investigated in order to optimize efficiency, selectivity and spectral line width. Depending on your specific interests and background, as trainee you will be involved in different aspects of the project: setting-up and optimizing the laser system, developing efficient ionization schemes, characterizing the gas-jet dynamics and capture of photo ions in a radio frequency ion trap. At the end of the internship an oral presentation of the work performed is mandatory. applicant’s Current Degree program (preferred): Master in Physics or Master in Engineering majoring in physics or nanoscience and nanotechnology Responsible scientist(s): Dr. Rafael Ferrer, Prof. Piet Van Duppen, Prof. Mark Huyse Duration: between 3 and 6 months Stipend: yes

5. ri 3Relation between local structure and functionality in topological materials For decades, electronics has been based on the charge of electrons. By exploiting the additional degree of freedom of the electron spin (and the associated magnetic moment), spintronics promises a new generation of devices with superior performance and new functionalities. A new spintronics paradigm is emerging which is based on newly discovered topological materials and phenomena, instead of conventional semiconductors (e.g. Si or GaAs) and magnetic metals (e.g. Co and Ni) currently used in electronics and spintronics. Although the physics underlying the functionality of these new materials is fundamentally different from that of conventional semiconductors and magnetic materials, the electronic and topological phenomena can be tuned using equivalent approaches (doping and alloying). This internship is embedded in our group’s ongoing research on the relation between the functional properties (induced or modified by doping/alloying) and the local structure (of the dopants / alloying elements), based on a unique experimental approach that combines radioactive ion beams (at the ISOLDE facility at CERN) and high-brilliance X-ray radiation (at the European synchrotron – ESRF). In particular, the intern will study the local structure of doped and alloyed topological materials (e.g. Ge1-xSnxTe and Mn-doped Bi2Se3), using two complementary techniques: emission channeling (EC) and extended X-ray absorption fine structure (EXAFS). Applicant’s Current Degree Program (preferred): Physics Responsible scientist(s): Prof. Lino Pereira, Prof. André Vantomme, Prof. Kristiaan Temst Duration: +/- 3 months Stipend: +/- € 900/month Channeling spectrum of Mn-doped Bi2Se3

6. ri 4 Phonons in superconducting nanostructured materials In reduced dimensionality systems such as nanostructures, the vibrational properties, described by the phonon density of states (PDOS), are expected to be affected by geometrical confinement, leading to strong deviations from the bulk behavior. A good understanding of the size and elastic strain effects on the material vibrational properties is not only of great interest from a fundamental point of view but it will also be extremely valuable for a wide range of applications, such as for heat transfer control in nanoscale electronics devices. In this project we will quantitatively evaluate the influence of phonon confinement on the superconducting properties of Sn nanowires. We intend to investigate the vibrational properties of a model 2D confined system made of tin nanowires embedded in an alumina matrix (see picture). 2D confined systems have two confined directions, leaving the third direction, in the present case the direction parallel to the nanowires axis, unconfined. By performing this experiment, we expect to obtain insight into size and strain effects that may affect the phonon density of states of tin nanowires. In particular we aim at providing answers to the following questions: do we observe any size effect, and if so can it be related to the nanowires diameter? Does the confinement result in a PDOS anisotropy? How are the vibrational properties of tin nanowires modified as the temperature and thus the axial strain is increased? Can we make a correlation with the superconducting properties of the Sn nanowires? Applicant’s Current Degree Program (preferred): Physics Responsible scientist(s): Prof. Kristiaan Temst, Prof. André Vantomme, Prof. Margriet Van Bael Duration: +/- 3 months Stipend: +/- €900/month Electron microscopy picture of nanowires in an alumina matrix

7. ri 5 The skyrmion lattice in magnetic FeSi and FeGe films Magnetism of thin films is one of the core research topics in solid state physics. During the past ten years the focus of attention has shifted towards magnetism at the nanoscale regime, a regime which has become accessible due to the progress in deposition and lithography techniques, as well as to the progress in the sensitivity of advanced characterization techniques. Although some manifestations of magnetic interactions like ferromagnetism, antiferromagnetism, helical and cycloidal order have been known for a long time, nature still has some surprises in store: just over two years ago the first experimental evidence was found for the so-called ‘skyrmion’ state: this is the spontaneous formation of vortex-like spin structures while applying a modest magnetic field. These skyrmions arrange themselves in a hexagonal lattice (see figure), comparable to the vortex state in a type-II superconductor. As this is still a very recent finding, many fundamental questions are still unsolved, e.g. in what range of fields and temperatures does the skyrmion lattice appear, can we visualize the lattice in thin films, how is it related to the structure and morphology of the film? In this project we will prepare FeSi and FeGe thin film samples using solid phase epitaxy, a technique that we have been refining over the past two decades. In these samples we will study the skyrmion lattice using Mössbauer spectroscopy and we will use the powerful x-ray beams of a synchrotron to investigate the magnetic spin structure of skyrmions. With this project we will deliver a significant contribution to the deeper understanding of this new and exciting magnetic feature. Applicant’s Current Degree Program (preferred): Physics Responsible scientist(s): Prof. Kristiaan Temst, Prof. André Vantomme, Prof. Margriet Van Bael Duration: +/- 3 months Stipend: €900 / month Lorentz microscopy picture of the skyrmion lattice in FeGe

8. ri6Plasmin activation in thrombotic thrombocytopenia purpura Von Willebrand Factor (VWF) is a multimeric protein present in the blood, with an important role in vascular injury and prevention of blood loss. VWF can recruit platelets from the circulation, resulting in clot formation.To prevent spontaneous clot formation, the multimeric size of VWF needs to be regulated. The enzyme ADAMTS13 cleaves VWF into smaller multimers, thereby reducing its thrombotic potential. A deficiency in ADAMTS13 activity is associated with thrombotic thrombocytopenic purpura (TTP), a life-threatening pathology where microthrombi are blocking the smaller capillaries in several organs (Figure 1). As a result, the transport of oxygen and nutrients to organs is blocked, causing fever, neurological complications, renal impairment, and death when left untreated. TTP patients are treated with plasma exchange or with fresh frozen plasma to replenish ADAMTS13. However, not all patients respond to this treatment method, and only 80-90% of the patients survive an acute episode. The pathophysiology of TTP is still not fully understood. Patients with TTP only have sporadic acute episodes where microthrombi are formed. We and others have previously demonstrated that there are other enzymes present in the blood that are also able to cleave VWF. One of those enzymes is plasmin; an enzyme mostly known for its role in the cleavage of fibrin. We were able to demonstrate that plasmin is highly increased during acute TTP, and that unrestrained plasmin activity results in recovery from severe TTP symptoms in mice. Students doing an internship will actively participate in current scientific research on the role of plasmin within TTP pathophysiology. This will be done using techniques such as: in vivo experiments, ELISA, VWF multimer analysis, immunohistochemistry, western blot and flow cytometry. Applicant’s Current Degree program (preferred): Biomedical Sciences, Biochemistry, Bioengineering Responsible scientist(s): Prof. Dr. Karen Vanhoorelbeke, Dr. Claudia Tersteeg Duration: 2months Stipend: 500€/month Figure 1: Brain microvasculature containing occlusive VWF-rich microthrombi.

9. ri7Computer simulations of DNA dynamics DNA is not just a passive carrier of genetic information, but it is a molecule with remarkable physical properties. To interact with other biomolecules in the cell DNA often has to bend, stretch and twist. Each human cell contains about 2 meters of DNA, which are compressed in a nucleus of the size of the order of a micrometer. The way this compression is done is to date not fully clear. This example and many others from molecular biology have driven the interest of physicist towards the understanding of the physical (mechanical and thermodynamical) properties of DNA. In this summer internship the student will participate to one of the research projects of our group, which focuses on computer simulations of DNA dynamics. The student will learn to use molecular dynamics computer codes for efficient coarse-grained simulations of DNA, to run simulations and analyze the data. Coarse-graining refers to methods in which several atoms are clustered in a single bead in order to reduce the number of degrees of freedom of the system. In this way one can simulate long DNA sequences for long time and study phenomena which would not be accessible to all atom simulations. An example of the result of coarse-grained model (a “kissing stem-loop”) is shown in the figure obtained from the code oxDNA Applicant’s Current Degree program (preferred): Physics, Chemistry, Computer Science Responsible scientist(s): Prof. Enrico Carlon (enrico.carlon@kuleuven.be) Duration: Summer internship 2-3 months Stipend: Possible

10. ri8Reconstructing Floodplain Changes in Flanders Description Many rivers in West and Central Europe have undergone important changes through the Holocene period. Due to human impact such as deforestation and agricultural activities, sediment deposition in floodplains increased. As a consequence, the geomorphology and ecology of the floodplains changed. In some river systems the river changed from a marshy environment with diffuse water transport (no clear river channel present), towards a single channel meandering river as we know the rivers nowadays (see figure). However, when and how these changes occurred and what the exact role was of human impact for these changes is not clear for many areas in Flanders. Moreover, climate change, land use change, floodwater regulations etc. will potentially change floodplains in the future. To be able to predict and deal with these future changes in floodplains, we need reliable reconstructions of past changes in floodplain geomorphology and ecology for a variety of floodplain environments, thus using the past as a key to the future. For this project, we are looking for students that actively participate in reconstructing the geomorphological and ecological changes of floodplains in Flanders, to better understand past floodplain changes and to better predict future changes. The internship will include fieldwork (hand corings), lab-analyses (pollen extraction) and microscope work (pollen counting). applicant’s Current Degree program (preferred): Geography, Earth Sciences, Geology, Archaeology, Biology, Palaeobotany Responsible scientist(s): Prof. Gert Verstraeten, Dr. Nils Broothaers Duration: 3 months Stipend: maybe

11. ri 9Computational tools to simulate realistic solar, astrophysical or plasma physics scenarios This type of research concentrates on the dynamical interaction between plasmas (the fourth and most abundant state of all known matter in our universe) and magnetic fields. This interaction gives rise to a wide range of fascinating and spectacular phenomena, including all aspects of our local space weather related to coronal mass ejections (see picture). Plasma dynamics also governs planetary and stellar magnetospheric physics, the turbulent motions in accretion disks, up to the jets observed wherever stars are born or die, or the relativistic jets emerging from entire galaxies, as seen on images taken by the Hubble space telescope. We have developed unique expertise in all aspects of plasma-physical modeling, ranging from advanced analytical theories to the development, use and exploitation of state-of-the-art computational tools to simulate realistic solar, astrophysical or fundamental plasma physics scenarios. The Sun and the heliosphere are our favorite research objects and are regarded as a showcase for plasma behavior in other astrophysical objects. The macroscopic behavior of most plasmas can be described by the magnetohydrodynamical (MHD) model. In this model formulas from fluid dynamics are combined with formulas describing the interacting of magnetic fields and fluids. The topics of semester internships relate directly to the applications of the magnetohydrodynamical (MHD) model on solar astrophysics. The mathematical modeling using MHD is extremely varied and gives rise to a number of interesting mathematical analytical and numerical techniques and challenges. Students doing an internship actively participate in current scientific research on the modeling of coronal mass ejections, MHD shock waves, seismology in coronal loops and in solar winds, magnetoseismology of magnetic accretion discs, astrophysical jets. (only semester internships, no summer research) Applicant’s Current Degree Program (Preferred): Mathematics, Applied Mathematics, Physics, Computer Science and Engineering Responsible scientist(s): Prof. Stefaan Poedts, Prof. Rony Keppens, Prof. Tom Van Doorsselaere Duration: 3 months

12. ri10 Identification and mode of action of volatile essential oil components affecting morphogenesis in the human fungal pathogen Candida albicans Candida albicans is a commensal in most if not all humans. When the immune system is working perfectly, it does not cause any harm. When the immune system is weakened, e.g. AIDS patients, it becomes virulent and results in death of the patients in about 50 % of the cases. Virulence is mostly associated with change in morphology from yeast cells to hyphal cells. So if we can block morphogenesis, we can block virulence and we allow the yeast form cells to stay there as a commensal. In our lab we have a large collection of essential oils. Each oil is a complex mixture of about 100 essential oil components (EOCs). We have developed a technology to identify active components in these complex mixtures without the need to purify these components. In one of our screens we have observed that volatile components in such an oil may affect the growth and/or morphogenesis of C. albicans cells at a distance, i.e the oil is not in direct contact with the cells. We aim to determine which are the volatile components that have this activity at a distance and how do these molecules affect morphogenesis. In our lab we have a number of tools to investigate which of the known signal transduction pathways involved in morphogenesis may be involved. If identified we will use the pure EOC to perform RNAseq analysis to help in unraveling the mode of action. We will also try to isolate suppressor mutants that again undergo morphogenesis as this may also result in the identification of the pathway involved. You will gain expertise in microbiology, molecular biology, cell biology and will use state-of-the-art technologies to solve our research question. applicant’s Current Degree program (preferred): Biology, Biochemistry, Biotechnology, Biomedical Responsible scientist(s): Prof. Patrick Van Dijck, Adam Feyaerts, Eva Pauwels Duration: 2 to 3 months Stipend: possibly