J.J.M. van Dijk

Seed sex ratio in dioecious plants depends on relative dispersal of pollen and seeds: an example using a chessboard simulation model

Two principles are important for the optimal sex ratio strategy of plants. (1) Sib mating. Because seed dispersal is restricted, sib mating may occur which selects for a female bias in the seed sex ratio. (2) Local resource competition (LRC). If a plant produces pollen its nuclear genes are dispersed in two steps: first through the pollen and then, if the pollen is successful in fertilizing an ovule on another plant, through the seed. If the plant produces an ovule, its genes are dispersed only through the seed. By making pollen instead of ovules the offspring of a single plant is then spread out over a wider area. This reduces the chance that genetically related individuals are close together and need to compete for the same resource. The effect is the strongest if pollen is dispersed over a much wider area than seeds. Less LRC for paternally vs. maternally derived offspring selects for a male bias in sex allocation.

T-Cell Activation by Bispecific Monoclonal Antibodies for Lysis of Renal Cell Carcinoma In Vitro

Patients with distant metastases from renal cell carcinoma (RCC) have a poor prognosis: The median survival is 6–8 months. Because of the relative resistance to radio- and chemotherapy, RCC patients may benefit from new treatment modalities, e.g., immunotherapy.