In response to an infection, proinfl ammatory cytokines stimulate lymphocytes to take up nutrients so that they can proliferate and mount an immune response. Once the infection is cleared, however, cytokine levels decline and the lymphocytes’ nutrient supply is abruptly cut off. Most of the cells quickly die by apoptosis, but a small fraction survive and differentiate into longlived memory cell...

Cells in an early embryo need to downsize their DNA. Ladouceur et al. show that a cell’s size and the size of its nucleus determine how small its chromosomes become (1). Like someone who’s moved from a house to an apartment, cells in an early embryo run into space limitations. The embryo remains the same size for its fi rst few divisions, so the cells have to become much smaller, shrinking by a...

shrink fit process is a useful technique in order to introduce beneficial residual stress in compound pressure vessels. in this paper, the effects of geometrical tolerances on residual stresses have been studied for a compound shrink fitted pressure vessel, practically. three layers, which are designed based on an optimum nominal thickness and overlap dimensions and tolerances, have been fitted...

Nowadays, functionally graded materials (FGM) are widely used in many industrial, aerospace and military fields. On the other hand, the interest in the use of shrink-fitted assemblies is increasing for designing composite tubes, high-pressure vessels, rectors and tanks. Although extensive researches exist on thick-walled cylindrical shells, not many researches have been done on shrink-fitted th...