Cell Division

We model cell division by periodically dividing the mtDNA within the simulated cell into two subpopulations, representing the two daughter cells. Since the division will not be exactly even, we again use a Poisson model for the division of the mtDNA between the two daughter cells. We must determine separately the number of mutant and wild-type mtDNA that end up in each daughter cell. Let W0 represent the number of wild-type mtDNA in the parent cell and Wx and W2 the number in the two daughter cells, with W0 = Wx + W2. Similar definitions are made for the mutant mtDNA. Then we have the following.

Wi = Poisson(Wo/2) W2 = Wo — Wi Mi = Poisson(Mo/2) M2 = M0 — M1

where Wcopy is the number of wild-type mtDNA copied in the time At and Mcopy is the number of mutant mtDNA copied. If more than one type of mutant mtDNA is being modeled in the simulation, then the term Mcopy can be further subdivided into these mutation subtypes. Based on the assumption that there is no replicative advantage to the mutants, we model the number of wild-type and mutant copied as a binomial process. Let W be the number of wild-type mtDNA and M be the number of mutant, with the total number of mtDNA N = W + M. Then we can write where the notation binomial(ncopy, W/N) means that a total of ncopy objects are being chosen from a population

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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