Mouse embryonic stem cells (ESCs) cultured in serum are characterized by hyper-phosphorylated RB protein, lack of G1 control, and rapid progression through the cell cycle. Here, we show that ESCs grown in the presence of two small-molecule inhibitors (2i ESCs) have a longer G1-phase with hypo-phosphorylated RB, implying that they have a functional G1 checkpoint. Deletion of RB, P107, and P130 i...

The game coloring number gcol(G) of a graph G is the least k such that if two players take turns choosing the vertices of a graph then either of them can insure that every vertex has less than k neighbors chosen before it, regardless of what choices the other player makes. Clearly gcol(G) ≤ ∆(G) + 1. Sauer and Spencer [20] proved that if two graphs G1 and G2 on n vertices satisfy 2∆(G1)∆(G2) < ...

Use vi , i , i , i to denote order, connectivity, edge-connectivity and minimum degree of a graphGi for i=1, 2, respectively. For the connectivity and the edge-connectivity of the Cartesian product graph, up to now, the best results are (G1×G2) 1+ 2 and (G1×G2) 1+ 2. This paper improves these results by proving that (G1×G2) min{ 1+ 2, 2+ 1} and (G1×G2)= min{ 1+ 2, 1v2, 2v1} ifG1 andG2 are conne...

In budding yeast, overcoming of a critical size to enter S phase and the mitosis/mating switch--two central cell fate events--take place in the G1 phase of the cell cycle. Here we present a mathematical model of the basic molecular mechanism controlling the G1/S transition, whose major regulatory feature is multisite phosphorylation of nuclear Whi5. Cln3-Cdk1, whose nuclear amount is proportion...

The existence of a partition of the common set of the vertices of two forests into two subsets, when difference of their capacities in the neighbourhood of each vertex of each forest not greater than 2 is proved, and an example, which shows that improvement of the specified constant is impossible is brought. In this paper we continue researches started in [1-2], devoted to locally-balanced part...

This paper deals with the modeling of G1 bifurcation. A branch-blending strategy is applied to model the bifurcation such that the coherence among the individual branching segments is characterized. To achieve this, bicubic Bézier patches are first used to generate three half-tubular surfaces by sweeping operations. The bifurcation modeling is then converted to a problem of filling two triangul...