Physics of life
Jan Koenderink (Koninklijke Vlaamse Academie van België voor Wetenschappen en Kunsten, Brussel & Delft Technical University)
Does monocular visual space contain planes?
The issue of the existence of planes - understood as the carriers of a nexus of straight lines - in the monocular visual space of a stationary human observer has never been addressed. The most recent empirical data apply to binocular visual space and date from the 1960s. This appears to be both the first and also the last time this basic issue was addressed empirically. Yet the question is of considerable conceptual interest. Here we report on a direct empirical test of the existence of planes in monocular visual space for a group of sixteen experienced observers. For the majority of these observers monocular visual space lacks a projective structure, albeit in qualitatively different ways. This greatly reduces the set of viable geometrical models. e.g., it rules out all of the classical homogeneous spaces (the Cayley-Klein geometries) such as the familiar Luneburg model. The qualitatively different behavior of experienced observers implies that the generic population might well be inhomogeneous with respect to the structure of visual space.
[1] J. Foley, "Desarguesian property in visual space", J.Opt.Soc.Am. 54, 684-692, 1964.
Michael J. Schöning (INB,
Bioreceptors coupled to microelectronic field-effect devices
The coupling of semiconductor field-effect devices (FEDs) together with chemical and biological recognition elements, like functional intelligent materials, biomolecules and living cells, represents an attractive platform for creating various bio- and chemical sensors, multi-parameter analysis systems and bio-chips. The presentation is focussing on recent developments and current research activities in the field of (bio-)chemically modified FEDs at the Institute of Nano- and Biotechnologies, scaling down from capacitive EIS (electrolyte-insulator-semiconductor) sensors and LAPS (light-addressable potentiometric sensor) to ISFETs (ion-sensitive field-effect transistor). Selected examples of application of FEDs are presented.
Wolfgang Eberle (IMEC Leuven, Bioelectronic Systems Group)
The artificial synapse – a platform blend of electronics and biology
Abundant methods exist to interact with biological cells in order to sense or trigger reactions. Biochemical, electrical, and optical paradigms are in place in research. But can we combine these methods in readily available platforms in order to improve data correlation and finally lead to a next generation of drug development tools? A major step forward is the capability of establishing communication with single cells (be it neurons, cardiac cells, or cancer cells) by addressing them intentionally in such a platform. We report such a platform realized in a mass-producible CMOS-compatible process which has been tested with primary neuronal cultures and cardiac cells but can be extended to other cell types. A key ingredient of our platform are 3D nail-like structures attracting cells and influencing their development patterns. There is a balance to be found between imposing behavior on the cells and monitoring the cells freely. Finally, addressing the individual cells is like addressing the nodes in the network. But can we also address the connections between the cells, realizing an artificial synapse? Another challenge in miniaturization.
