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Université de Neuchâtel

Punishment and partner switching cause cooperative behaviour in a cleaning mutualism

Bshary, Redouan ; Grutter, Alexandra S.

In: Biology Letters, 2005, vol. 1, no. 4, p. 396-399

What are the mechanisms that prevent partners from cheating in potentially cooperative interactions between unrelated individuals? The cleaner fish Labroides dimidiatus and client reef fish both benefit from an interaction as long as the cleaner eats ectoparasites. However, the cleaner fish prefers some client mucus, which constitutes cheating. Field observations suggested that clients...

Université de Neuchâtel

Image scoring and cooperation in a cleaner fish mutualism

Bshary, Redouan ; Grutter, Alexandra S.

In: Nature, 2006, vol. 441, p. 975-978

Humans are highly social animals and often help unrelated individuals that may never reciprocate the altruist's favour. This apparent evolutionary puzzle may be explained by the altruist's gain in social image: image-scoring bystanders, also known as eavesdroppers, notice the altruistic act and therefore are more likely to help the altruist in the future. Such complex indirect reciprocity based...

Université de Neuchâtel

Properties of chiral self-assembled monolayers at the solid-liquid interface investigated by FT-IR ATR spectroscopy

Bieri, Marco ; Bürgi, T (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2007 ; 1926.

The main distinctive feature of modern surface science is that it deals with single crystal surfaces, which are well-defined from the viewpoint of their structure and composition. However, for the preparation of crystal surfaces and their analysis, the requirement of UHV equipment greatly limits applications. While atomically clean surfaces analyzed under artificial measurement conditions still...

Université de Neuchâtel

Spatial and Seasonal Patterns of Cattle Habitat use in a Mountain Wooded Pasture

Kohler, Florian ; Gillet, François ; Reust, Stéphanie ; Wagner, Helene H. ; Gadallah, Fawziah ; Gobat, Jean-Michel ; Buttler, Alexandre

In: Landscape Ecology, 2006, vol. 21, no. 2, p. 281-295

Management-oriented models of cattle habitat use often treat grazing pressure as a single variable summarizing all cattle activities. This paper addresses the following questions: How does the spatial pattern of cattle effects vary between cattle activities in a highly heterogeneous landscape? Do these patterns change over the grazing season as forage availability decreases? What are the...

Université de Neuchâtel

A peat core based estimate of Late-glacial and Holocene methane emissions from northern peatlands

Steinmann, Philipp ; Huon, S. ; Roos-Barraclough, F. ; Föllmi, Karl B.

In: Global and Planetary Change, 2006, vol. 53, no. 4, p. 233-239

We estimate the intensity of Late-glacial and Holocene methane emissions from peatlands based on their paleo net primary production (PNPP). The PNPP is derived from the carbon accumulation rates of the studied bog profile (Etang de la Gruère, Switzerland), which are corrected for the degree of peat degradation. The obtained PNPP curve is taken as a proxy for methane emissions. It shows...

Université de Neuchâtel

Soil Phosphorus Uptake by Continuously Cropped Lupinus albus : A New Microcosm Design

Le Bayon, R. C. ; Weisskopf, L. ; Martinoia, E. ; Jansa, J. ; Frossard, E. ; Keller, F. ; Föllmi, Karl B. ; Gobat, Jean-Michel

In: Plant and Soil, 2006, vol. 283, no. 1-2, p. 309-321

When grown in soils with sparingly available phosphorus (P), white lupin (Lupinus albus L.) forms special root structures, called cluster roots, which secrete large amounts of organic acids and concomitantly acidify the rhizosphere. Many studies dealing with the understanding of this P acquisition strategy have been performed in short time experiments either in hydroponic cultures or in...

Université de Neuchâtel

Altered carbon cycling and trace-metal enrichment during the late Valanginian and early Hauterivian

Kuhn, Oliver ; Weissert, Helmut ; Föllmi, Karl B. ; Hennig, Susanne

In: Eclogae Geologicae Helvetiae, 2005, vol. 98, no. 3, p. 333-344

Carbonates of Valanginian age deposited in the Tethys and Atlantic Oceans show a distinct positive δ13C excursion (Δ δ13C = 1.5‰-2‰) in sections of the neritic, hemipelagic, and pelagic environment. This excursion records a major climate-induced perturbation of the global carbon system. The δ13C excursion is accompanied by enrichments in manganese (Mn) and...

Université de Neuchâtel

Macro-programmable DSP architecture for parallel/pipelined data pathunits, targeted for FFT based algorithms

Drollinger, Andreas ; Heubi, Alexandre ; Balsiger, Peter ; Pellandini, Fausto

In: Proceedings of the International Conference on Signal Processing, Applications and Technology (ICSPAT), 2000, p. 1-5

A macro-programmable DSP architecture is presented, which is very well situated for the implementation of algorithms with regular data flow graphs, like FFTs. A smart grouping of the algorithm together with the macrocode concept reduce drastically the control and address generation overhead of the DSP and shorten the computation time. This is finally manifested in very low-power consumption,...

Université de Neuchâtel

ASIC DSP compiler for optimized synthesis

Drollinger, Andreas ; Heubi, Alexandre ; Balsiger, Peter ; Pellandini, Fausto

In: Proceedings of the International Conference on Signal Processing, Applications and Technology (ICSPAT), 2000, p. 1-5

This paper presents a high level DSP architecture compiler for cycle-constrained filters and datapath applications. The tool offers an easy way to get, from an equation representation of a filter, a synthetisable VHLD description of an application specific DSP architecture. Inputs of the DSP compiler are an equation file to define the filter structure and a resource definition file to specify the...

Université de Neuchâtel

Micro Power High-Resolution A/D Converter

Robert, Christian ; Grisoni, L. ; Heubi, Alexandre ; Balsiger, Peter ; Pellandini, Fausto

In: Proceedings of the International Conference on Signal Processing, Applications and Technology (ICSPAT), 1999, p. 1-5

Micro power converters are required for power sensitive, battery-operated devices. Keeping this goal in mind IMTdeveloped a 13-bit RSD cyclic converter. However, inaccuracies (capacitor mis-match, operation amplifier...) resulted in a relative precision behaviour. The implementation of a correction algorithm in a 2μm CMOS technology is presented. It requires 1 mm2 and simulations show...