Radboud University Nijmegen

About: Radboud University Nijmegen is a education organization based out in Nijmegen, Gelderland, Netherlands. It is known for research contribution in the topics: Population & Randomized controlled trial. The organization has 35417 authors who have published 83035 publications receiving 3285064 citations. The organization is also known as: Catholic University of Nijmegen & Radboud University.

Room-Temperature Quantum Hall Effect in Graphene

Abstract: The quantum Hall effect (QHE), one example of a quantum phenomenon that occurs on a truly macroscopic scale, has attracted intense interest since its discovery in 1980 and has helped elucidate many important aspects of quantum physics. It has also led to the establishment of a new metrological standard, the resistance quantum. Disappointingly, however, the QHE has been observed only at liquid-helium temperatures. We show that in graphene, in a single atomic layer of carbon, the QHE can be measured reliably even at room temperature, which makes possible QHE resistance standards becoming available to a broader community, outside a few national institutions.

Book review: dynamic patterns: The self-organization of brain and behavior by, j. a. scott kelso, cambridge, ma : the mit press, 1995, hardbound, 334 pages, $49.95. isbn 0-262-11200-0

Abstract: Part 1 How nature handles complexity: what is a pattern? kinds of patterns principles of dynamic pattern formation the messages of self-organized patterns new laws to be expected in the organism matters of mind and matter the mind revealed? or, what this book's about. Part 2 Self-organization of behaviour - the basic picture: some historical remarks about the science of psychology are actions self-organized? if so, how? from synergies to synergetics requirements of a theory of self-organized behaviour. Part 3 Self-organization of behaviour - first steps of generalization: Hubris tempered? on Harvard horses and Russian cats coordination between components of an organism coordination between organisms on coupling. Part 4 Extending the basic picture - breaking away: relative coordination relative coordination explained absolute and relative coordination unified related models - fireflies, lampreys, and lasers instability and the nature of life - the intermittency mechanism exposed postscript. Part 5 Intentional dynamics: goal-directness in biology the second cornerstone of biological self-organization - informational specificity intentional behaviourial change related views - termites, predator-prey cycles, and quantum mechanics summing up. Part 6 Learning dynamics: issues in learning the main concepts the 'seagull effect' - competition and cooperation questions of learning transfer and generalization - symmetry again behaviourial development evolution and morphogenesis summary and conclusions. Part 7 perceptual dynamics: the barrier of meaning - perceptual dynamics I the barrier of meaning - perceptual dynamics II metastability of mind principles of perceiving - calculating, settling, resonating, and twinkling. Part 8 Self-organizing dynamics of the nervous system: microscale events mesoscale events macroscale events extending the basic picture...again postscript on etymology. Part 9 Self-organization of the human brain: prolegomenon obstacles to understanding the brain is not a static machine the 'brain dynamics' approach - fractural dimension spatiotemporal patterns of the brain models of brain behaviour - coupled modes and Sil'nikov chaos summary and conclusions - brain behaviour.

Shaping functional architecture by oscillatory alpha activity : gating by inhibition

Abstract: In order to understand the working brain as a network, it is essential to identify the mechanisms by which information is gated between regions. We here propose that information is gated by inhibiting task-irrelevant regions, thus routing information to task-relevant regions. The functional inhibition is reflected in oscillatory activity in the alpha band (8-13 Hz). From a physiological perspective the alpha activity provides pulsed inhibition reducing the processing capabilities of a given area. Active processing in the engaged areas is reflected by neuronal synchronization in the gamma band (30-100 Hz) accompanied by an alpha band decrease. According to this framework the brain should be studied as a network by investigating cross-frequency interactions between gamma and alpha activity. Specifically the framework predicts that optimal task performance will correlate with alpha activity in task-irrelevant areas. In this review we will discuss the empirical support for this framework. Given that alpha activity is by far the strongest signal recorded by EEG and MEG, we propose that a major part of the electrophysiological activity detected from the working brain reflects gating by inhibition.

Field-effect tunneling transistor based on vertical graphene heterostructures.

Abstract: An obstacle to the use of graphene as an alternative to silicon electronics has been the absence of an energy gap between its conduction and valence bands, which makes it difficult to achieve low power dissipation in the OFF state We report a bipolar field-effect transistor that exploits the low density of states in graphene and its one-atomic-layer thickness Our prototype devices are graphene heterostructures with atomically thin boron nitride or molybdenum disulfide acting as a vertical transport barrier They exhibit room-temperature switching ratios of ≈50 and ≈10,000, respectively Such devices have potential for high-frequency operation and large-scale integration