Yearbook 2012

Filter by institute

The counting of algebraic curves on surfaces is a classical topic of algebraic geometry, which has gained new interest because of the advent of string theory from physics. After a short introduction into enumerative invariants of curves a refinement is considered. Instead of a number of curves one gets a polynomial, which can be related to invariants of real and tropical algebraic geometry. more
We give a glimpse into the world of reflection groups, Coxeter groups, Lie groups and Kazhdan-Lusztig polynomials. more
That a subject knows something is conceptualized as it ruling out certain facts while considering other facts possible. Thus the distinction between ‘ruled out’ and ‘possible’ draws upon a given set of conceivable facts. If in a model the knowledge of several subjects is based on the same conceivable facts, everyone receives the same information about what anyone can possibly know (identical ‘awareness’). Overcoming this restriction allows more differentiated analyses of economic decision making. more

High-performance computing, data services and visualization

Max Planck Computing and Data Facility (MPCDF) Dohmen, Renate; Lederer, Hermann; Rampp, Markus; Reetz, Johannes; Reuter, Klaus; Schott, Andreas
The RZG supports optimization of complex applications from plasma physics, astrophysics, materials science, and other disciplines for massively parallel high-performance computers and offers data management services and infrastructure. Moreover, the RZG provides data visualization services for the exploration and quantitative analysis of simulation results. The RZG plays a leading role in projects within the MPG and at national and European level.   more
Perception of visual motion is of fundamental importance in order to safely move around and to skillfully reach and grasp objects. When using visual input to control goal-directed motion, our brain makes a decision to select the object of greatest salience in the visual field in order to steer the eyes, the head and the hand towards it. Even the small zebrafish larva exhibits a complex goal-directed behavior thanks to its refined visual system. Research at the Max Planck Institute for Medical Research now reveals how motion stimuli are processed in the brain of this little hunter. more

Regulation of axon growth

Max Planck Institute of Experimental Medicine Kannan, Madhuvanthi; Schwedhelm-Domeyer, Nicola; Stegmüller, Judith
Axon growth is an essential event in the developing central nervous system. While a large body of evidence characterizes extrinsic mechanisms, there is little knowledge about intrinsic signaling pathways of axon growth regulation. The E3 ligase Cdh1-APC has been identified as a novel intrinsic inhibitor of axon growth. Thus, the research focuses on the elucidation of the Cdh1-APC signaling pathway. more
In our research work we focused on novel labeling methods using (3+2) cycloadditions. Our main goal was to synthesize radiofluorinated 1,3-dipoles, which easily react with double and triple bonds. A second aim was to develop a simple method for the preparation of radiolabeled β-lactams. Furthermore 1,2-didehydrobenzene was used in association with the novel 1,3-dipoles to produce 18F-labeled homo- and heterocycles, which are difficult to prepare via conventional procedures. These approaches extend the spectrum of accessible radiolabeled probes and enable access to novel intelligent PET probes. more
Climate Engineering employs technical methods to mitigate climate change without lowering anthropogenic CO2 emissions. One of these methods, the artificial increase of ocean alkalinity, has been proposed to enhance the oceanic uptake of atmospheric CO2 and counteract the ongoing ocean acidification. We used a global biogeochemical model to show that artificial ocean alkalinity input must be 200 times higher than the input by natural weathering flux to hold the global seawater pH close to today’s value. The effects on ocean biogeochemistry would be substantial. more
Hydrogen (H2) plays a crucial role in global carbon cycles. Hydrogenases - H2 producing and utilizing enzymes - are pivotally involved in biological systems for the turnover of H2. Three types of hydrogenases are known: [NiFe]-, [FeFe]- and [Fe]-hydrogenases. The [Fe]-hydrogenase functions in the methanogenic pathway of hydrogenotrophic methanogenic archaea. This new type of hydrogenase contains a unique iron-guanylylpyridinol (FeGP) cofactor. We are studying the structure and function of both the enzyme and cofactor as well as the FeGP cofactor biosynthesis. more
Microbiological and biogeochemical processes in the ocean are of essential significance for marine ecosystems and play an important role in the Earth’s climate. A detailed understanding of all contributing components, including the supply and transport of trace elements, is therefore of highest interest for marine and climate sciences. Using isotope ratios of trace elements in the ocean, the Max Planck Research Group for Marine Isotope Geochemistry strives to contribute to an improved understanding of the role of geochemical cycles for marine ecosystems and global climate change. more

Ultrafast magnons for spintronics

Max Planck Institute of Microstructure Physics Zakeri Lori, Khalil; Zhang, Yu; Chuang, Tzu-Hung; Kirschner, Jürgen
Magnons are the wave-like motions of the magnetic moments in a magnetically ordered solid. Similar to other waves, magnons may also be used for information processing. The study of wavelength, frequency and lifetime of magnons in magnetic solids is an important area of research. At the Max Planck Institute of Microstructure Physics the properties of magnons excited at ferromagnetic surfaces are investigated using spin-polarized electron spectroscopy. more
Go to Editor View