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Responses of soil biological processes to elevated atmospheric [CO2] and nitrogen addition in a poplar plantation

de nationalité suisse et originaire de Zurich (ZH) et Lucerne (LU) acceptée sur proposition du jury:

The recent discovery of dark energy has prompted an investigation of ways in which the accelerated expansion of the universe can be realized. In this dissertation, we present two separate projects related to dark energy. The first project analyzes a class of braneworld models in which multiple branes float in a five-dimensional anti-de Sitter bulk, while the second investigates a class of dark energy models from an effective field theory perspective. Investigations of models including extra dimensions have led to modifications of gravity involving a number of interesting features. In particular, the Randall-Sundrum model is well-known for achieving an amelioration of the hierarchy problem. However, the basic model relies on Minkowski branes and is subject to solar system constraints in the absence of a radion stabilization mechanism. We present a method by which a four-dimensional low-energy description can be obtained for braneworld scenarios, allowing for a number of generalizations to the original models. This method is applied to orbifolded and uncompactified N-brane models, deriving an effective four-dimensional action. The parameter space of this theory is constrained using observational evidence, and it is found that the generalizations do not weaken solar system constraints on the original model. Furthermore, we find that general

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Abstract—This paper highlights and characterizes the main obstacle to deploying a robust wireless sensor network testbed: the USB connections that link each of the nodes via ethernet gateways to the central server. Unfortunately, these connections are also the components that, when properly installed, can reduce testbed costs by attaching multiple nodes per gateway. After illustrating how unreliable current solutions can become (regardless of the used sensor nodes, USB cabling, or gateway setup), a set of experiments led to a list of dos and don’ts in testbed deployment. Furthermore, a simple and cost-effective suggestion is presented that allows to bypass current USB backchannel issues, leading to a more robust testbed that avoids manual maintenance of individual nodes. Index Terms—experimentation; testbeds; testbed reliability; sensor node reprogramming; universal serial bus I.

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution

Abstract. We review theoretical models of individual motility as well as collective dynamics and pattern formation of active particles. We focus on simple models of active dynamics with a particular emphasis on nonlinear and stochastic dynamics of such self-propelled entities in the framework of statistical mechanics. Examples of such active units in complex physico-chemical and biological systems are chemically pow-ered nano-rods, localized patterns in reaction-diffusion system, motile cells or macroscopic animals. Based on the description of individual motion of point-like active particles by stochastic differential equations, we discuss different velocity-dependent friction functions, the impact of various types of fluctuations and calculate characteristic observ-ables such as stationary velocity distributions or diffusion coefficients. Finally, we consider not only the free and confined individual active dynamics but also different types of interaction between active par-ticles. The resulting collective dynamical behavior of large assemblies and aggregates of active units is discussed and an overview over some recent results on spatiotemporal pattern formation in such systems is given. 1

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of baryon stopping are relevant to the physics of total entropy production, explaining why A+A and e + e − multiplicities are different at low beam energies. “Critical Point and the Onset of Deconfinement ” Workshop