the purpose of this study was to investigate the therapeutic effects of propolis on biochemical and microbiological parameters in muscle tissues of carp (cyprinus carpio, linnaeus 1758) exposed to arsenic. a sublethal concentration of arsenic (0.01 ppm) and/or 0.01 ppm propolis were administered to fish for seven days. biochemical parameters [ph, lactic acid, total volatile basic nitrogen (tvb-...

avian infectious bronchitis (ib) is a major cause of economic losses in poultry industry. the ib virus primarily affects respiratory tract, but various strains differ in their tropism for other target organs such as kidney and alimentary tract. the objective of this study was to estimate the pathogenicity of iranian ibv variant (ir-1), which is limited exclusively to iran. specific pathogen fre...

Biological cells are often found to sense their chemical environment near the single-molecule detection limit. Surprisingly, this precision is higher than simple estimates of the fundamental physical limit, hinting towards active sensing strategies. In this work, we analyse the effect of cell memory, e.g. from slow biochemical processes, on the precision of sensing by cell-surface receptors. We...

We propose a general method for simplifying master equations by eliminating from the description rapidly evolving states. The physical recipe we impose is the suppression of these states and a renormalization of the rates of all the surviving states. In some cases, this decimation procedure can be analytically carried out and is consistent with other analytical approaches, such as in the proble...

We develop tools from computational algebraic geometry for the study of steady state features of autonomous polynomial dynamical systems via elimination of variables. In particular, we obtain nontrivial bounds for the steady state concentration of a given species in biochemical reaction networks with mass-action kinetics. This species is understood as the output of the network and we thus bound...

Intracellular biochemical reactions exhibit a rich dynamical phenomenology which cannot be explained within the framework of mean-field rate equations and additive noise. Here, we show that the presence of metastable states and radically different time scales are general features of a broad class of autocatalytic reaction networks, and that this fact may be exploited to gain analytical results....

In order to produce specific complex structures from a large set of similar biochemical building blocks, many biochemical systems require high sensitivity to small molecular differences. The first and most common model used to explain this high specificity is kinetic proofreading, which has been extended to a variety of systems from detection of DNA mismatch to cell signaling processes. While t...

Two divergent modelling methodologies have been adopted to increase our understanding of metabolism and its regulation. Constraint-based modelling highlights the optimal path through a stoichiometric network within certain physicochemical constraints. Such an approach requires minimal biological data to make quantitative inferences about network behaviour; however, constraint-based modelling is...