Boissel: Đối với tôi, vô cảm với các giá trị tham số có nghĩa là các thông số vô dụng trong mô hình. Cassman: Trong những trường hợp (ít nhất, số lượng khá hạn chế điều này dường như là đúng) là kiến trúc của hệ thống để xác định đầu ra và không ¢ Speci c giá trị tham số. Có vẻ như rất có thể đây chỉ là | 178 DISCUSSION when it is not attached to the lattice. There are efficient analytical expressions for computing this effect Lagerholm Thompson 1998 and it would be very interesting to combine such equation-based methods with our individual-based stochastic approach. Noble When Raimond Winslow was presenting his work on combining stochastic modelling with differential equation modelling as I understand it this leads to greatly increased computational times. When I recently heard Dennis Bray present some of this work he gave the impression that the stochastic computational methods that you are using actually go extremely fast. What is the explanation for this Shimizu If it is the case that there are certain complexes that have a large number of states so that a large number of equations would need to be integrated at every time point then stochastic modelling can be faster. Noble So it s a matter of whether each of those states were otherwise to be represented by kinetic expressions rather than by an on-off switch. Winslow The reason this is difficult for us is that we are describing stochastic gating of a rather large ensemble of channels in each functional unit. Another confounding variable is the local Ca2 concentration because this is increasing the total number of states that every one of these channels can be in. I have a comment. We have now heard about models in three different areas. We have heard about a model of bacterial chemotaxis neural models that Les Loew described and the cardiac models that Andrew McCulloch and I have talked about. I grant you that in each one of these systems there are different experimental capabilities that may apply and thereby make the data available for modelling different in each case. But there are a lot of similarities between the mathematics and the computational procedures used in these systems. In each case we have dealt with issues of stochastic models where the stochastic nature comes in through the nature of channel .
