5 research outputs found
On deducing causality in metabolic networks
© 2008 Bodei et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution Licens
A Taxonomy of Causality-Based Biological Properties
We formally characterize a set of causality-based properties of metabolic
networks. This set of properties aims at making precise several notions on the
production of metabolites, which are familiar in the biologists' terminology.
From a theoretical point of view, biochemical reactions are abstractly
represented as causal implications and the produced metabolites as causal
consequences of the implication representing the corresponding reaction. The
fact that a reactant is produced is represented by means of the chain of
reactions that have made it exist. Such representation abstracts away from
quantities, stoichiometric and thermodynamic parameters and constitutes the
basis for the characterization of our properties. Moreover, we propose an
effective method for verifying our properties based on an abstract model of
system dynamics. This consists of a new abstract semantics for the system seen
as a concurrent network and expressed using the Chemical Ground Form calculus.
We illustrate an application of this framework to a portion of a real
metabolic pathway
A Formal Approach to Open Multiparty Interactions
We present a process algebra aimed at describing interactions that are
multiparty, i.e. that may involve more than two processes and that are open,
i.e. the number of the processes they involve is not fixed or known a priori.
Here we focus on the theory of a core version of a process calculus, without
message passing, called Core Network Algebra (CNA). In CNA communication
actions are given not in terms of channels but in terms of chains of links that
record the source and the target ends of each hop of interactions. The
operational semantics of our calculus mildly extends the one of CCS. The
abstract semantics is given in the style of bisimulation but requires some
ingenuity. Remarkably, the abstract semantics is a congruence for all operators
of CNA and also with respect to substitutions, which is not the case for strong
bisimilarity in CCS. As a motivating and running example, we illustrate the
model of a simple software defined network infrastructure.Comment: 62 page
Programmazione logica e biochimica: analisi di reflui
L'inquinamento ambientale e' una delle problematiche piu' importanti perche' la vita
degli organismi e' in pericolo in presenza di un ambiente contaminato.
Il monitoraggio biologico ha lo scopo di tenere sotto controllo il livello di inquinamento studiando le variazioni biologiche
che avvengono negli organismi in relazione alla loro esposizioni a sostanze tossiche. Tramite il rilevamento dell'attivita'
enzimatica nei reflui e' possibile valutare il livello tossicologico di un refluo per l'ambiente. L'utilizzo della programmazione
logica ci ha permesso di descrivere il dominio dei reflui e, partendo dai dati di laboratorio, di indurre la loro composizione
individuando le sostanze tossiche responsabili dell'impatto sull'attivita' enzimatica
A static analysis for Brane Calculi providing global occurrence counting information
In this paper we propose a static analysis for Brane Calculi [1], based on Abstract Interpretation [2] techniques. Our analysis statically approximates the dynamic behaviour of Brane systems, by providing a description of the possible hierarchical structure of membranes and of the processes possibly associated to each membrane, together with global occurrence counting information. Our analysis can be computed in polynomial time. We apply it to investigate several biological systems in which occurrence counting information plays a crucial role. In particular, our case study concerns the formation of the haemoglobin polymer in presence of alterations and investigate the influence that such alterations have on the ability of the haemoglobin polymer to bind oxygen molecules