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Université de Fribourg

Circadian rhythms in murine pups develop in absence of a functional maternal circadian clock

Jud, Corinne ; Albrecht, Urs

In: Journal of Biological Rhythms, 2006, vol. 21, no. 2, p. 149-154

A genetic approach was used to investigate whether the emergence of circadian rhythms in murine pups is dependent on a functional maternal clock. Arrhythmic females bearing either the mPer1Brdm1/Per2Brdm1 or mPer2Brdm1/Cry1-/- double-mutant genotype were crossed with wild-type males under constant darkness. The heterozygous offspring have the genetic...

Università della Svizzera italiana

Agent communication and institutional reality

Fornara, Nicoletta ; Viganò, Francesco ; Colombetti, Marco

In this paper we propose to regard an Agent Communication Language (ACL) as a set of conventions to act on a fragment of institutional reality, defined in the context of an artificial institution. Within such an approach, we first reformulate a previously proposed commitment-based semantics for ACLs. In particular we show that all commonly used types of communicative acts can be defined in terms...

Università della Svizzera italiana

An operational approach to norms in artificial institutions

Viganò, Francesco ; Fornara, Nicoletta ; Colombetti, Marco

The notion of artificial institution is crucial for the specification of open and dynamic interaction frameworks where heterogeneous and autonomous agents can interact to face problems in various fields, like for instance electronic commerce, business-to-business (B2B) applications, and personal assistant applications. In our view the specification of artificial institutions requires a clear...

Università della Svizzera italiana

Artificial institutions : a model of institutional reality for open multiagent systems

Fornara, Nicoletta ; Viganò, Francesco ; Verdicchio, Mario ; Colombetti, Marco

Software agents’ ability to interact within different open systems, designed by different groups, presupposes an agreement on an unambiguous definition of a set of concepts, used to describe the context of the interaction and the communication language the agents can use. Agents’ interactions ought to allow for reliable expectations on the possible evolution of the system; however, in open...

Università della Svizzera italiana

From context to system and back : how systems emerge from actors cognitive and social interactions : a system dynamics perspective

Colombo, Gianluca ; Mollona, Edoardo

In this paper, the system is viewed as a construction based on the actors’ cognitive and social interactions. The system is the result of multiple – actor sense making (Weick 1995), but at the same time it orients social sense making. In this process each actor’s point of view is a representation of both the system and the context perceived as pertinent by the actor. In other words, the...

Université de Fribourg

Callosal connections of dorsal versus ventral premotor areas in the macaque monkey: a multiple retrograde tracing study

Boussaoud, Driss ; Tanné-Gariépy, Judith ; Wannier, Thierry ; Rouiller, Eric M.

In: BMC Neuroscience, 2005, vol. 6, p. 67

Background: The lateral premotor cortex plays a crucial role in visually guided limb movements. It is divided into two main regions, the dorsal (PMd) and ventral (PMv) areas, which are in turn subdivided into functionally and anatomically distinct rostral (PMd-r and PMv-r) and caudal (PMd-c and PMv-c) sub-regions. We analyzed the callosal inputs to these premotor subdivisions following 23...

Université de Fribourg

Distributed virtual worlds : abstract model and design of the MaDViWorld software framework

Fuhrer, Patrik ; Pasquier-Rocha, Jacques (Dir.) ; Savoy, Jacques (Codir.)

Thèse de doctorat : Université de Fribourg, 2004 ; no 1458.

Distributed virtual worlds are multi-user applications running on several computers connected by a network. They go beyond the traditional document based World Wide Web since multiple users interact within a shared space and are aware of each other. Distance learning, telemedicine, adventure games, virtual shopping malls, virtual conferencing, virtual museums, virtual e-banking are just some...

Université de Fribourg

Endothelial nitric oxide synthase gene transfer restores endothelium–dependent relaxations and attenuates lesion formation in carotid arteries in apolipoprotein E–deficient mice

Mujynya-Ludunge, Kathi ; Viswambharan, Hema ; Driscoll, Robert ; Ming, Xiu-Fen ; Segesser, Ludwig K. von ; Kappenberger, Lukas ; Yang, Zhihong ; Vassalli, Giuseppe

In: Basic Research in Cardiology, 2005, vol. 100(2), p. 102

Nitric oxide (NO) and monocyte chemoattractant protein–1 (MCP-1) exert partly opposing effects in vascular biology. NO plays pleiotropic vasoprotective roles including vasodilation and inhibition of platelet aggregation, smooth muscle cell proliferation, and endothelial monocyte adhesion, the last effect being mediated by MCP–1 downregulation. Early stages of arteriosclerosis are associated...

Université de Fribourg

Probabilistic model-based diagnostics

Anrig, Bernhard ; Kohlas, Jürg (Dir.)

This thesis presents the concept of general argumentation systems, a framework for representing uncertain knowledge using information algebras and information systems as well as probability algebras. Argumentation systems are a generalization of assumption-based systems and propositional argumentation systems and can deal with very general formalisms. We show also that an argumentation system...

Université de Fribourg

Divergence and convergence of thalamocortical projections to premotor and supplementary motor cortex: a multiple tracing study in the macaque monkey

Morel, Anne ; Liu, Jian ; Wannier, Thierry ; Jeanmonod, Daniel ; Rouiller, Eric M.

In: European Journal of Neuroscience, 2005, vol. 21(4), p. 1007

The premotor cortex of macaque monkeys is currently subdivided into at least six different subareas on the basis of structural, hodological and physiological criteria. To determine the degree of divergence/convergence of thalamocortical projections to mesial [supplementary motor area (SMA)-proper and pre-SMA] and lateral (PMd-c, PMd-r, PMv-c and PMv-r) premotor (PM) subareas, quantitative...