Detecting positive selection is a challenging task. We propose a method for detecting past positive selection through ongoing negative selection, based on comparison of the parameters of intraspecies polymorphism at functionally important and selectively neutral sites where a nucleotide substitution of the same kind occurred recently. Reduced occurrence of recently replaced ancestral alleles at...

The commercial availability of random peptide libraries displayed on the M13 phage is increasing their use forstudies on epitope identification, enzyme inhibitors, receptor ligands, etc. In this study two experimentswhere planned for selection of peptides. First with sheep antibodies, the positive selector was IgG, preparedon Protein G column from a pool of 11 sheeps immunized...

The probability that an advantageous mutant rises to fixation in a viral quasispecies is investigated in the framework of multitype branching processes. Whether fixation is possible depends on the overall growth rate of the quasispecies that will form if invasion is successful rather than on the individual fitness of the invading mutant. The exact fixation probability can be calculated only if ...

—This paper explores new roles that traditionally rural kinship networks organized around the marriage institution might play in improving labor market outcomes in urban Africa. Using new data from Kisumu, Kenya, and controlling for selection into marriage, we find that marriage significantly increases employment levels and incomes in our sample of migrants. At the same time, marriage increases...

The commitment of a pluripotential stem cell to the B-cell lineage and the progression of the committed B-cell precursor to a mature, immunocompetent B-cell is a highly regulated process. Extrinsic processes and internal programmes initiate and regulate the changes in gene expression that alter the phenotype and functional characteristics of the B-cell as it proceeds through its maturation. Man...