Organisms with external fertilization are often sperm limited, and in echinoids, larger eggs have a higher probability of fertilization than smaller eggs. This difference is thought to be a result of the more frequent sperm-egg collisions experienced by larger targets. Here we report how two components of egg target size, the egg cell and jelly coat, contributed to fertilization success in a se...

Complex life cycles have evolved independently numerous times in marine animals as well as in disparate algae. Such life histories typically involve a dispersive immature stage followed by settlement and metamorphosis to an adult stage on the sea floor. One commonality among animals exhibiting transitions of this type is that their larvae pass through a 'precompetent' period in which they do no...

Drawing on 265 national sample surveys spanning 83 countries we find that there was a net decrease in the overall incidence of consumption poverty over 1987-98. But it was not enough to reduce the total number of poor by various definitions. The incidence of poverty fell in Asia and the Middle East—North Africa. It changed little in Latin America and Sub-Saharan Africa, and it rose sharply in E...

In the 14 July 1997, issue of Lancet, Schlemper et al. [1] reported a study in which four Japanese and four Western pathologists (from the United States, Canada, Germany, and Finland) compared their diagnoses of gastric biopsy and resection specimens having epithelial lesions ranging from reactive, through preneoplastic, to invasive carcinoma. These pathologists independently classified microsc...