Background: Spermatozoa are able to sense an attractant molecule gradient and as a consequence, orient their movement towards the source of the attractant. This mechanism is known as sperm chemotaxis. In recent years, our laboratory contributed to the knowledge of several features of mammalian sperm chemotaxis. These include the size and physiological state of the chemotactic sperm population, ...

Echinochrome, the red coloring matter found in sea urchin eggs, is not uniformly dissolved in the cytoplasm, but is distributed in the form of granules, and may be associated in these formed elements with other cellular components. I t may exist, intracellularly at least, as a chromoprotein. That the echinochrome is not in solution in the unfertilized egg cell, but exists practically entirely i...

In birds, egg size aff ects chick growth and survival and it is an important component of reproductive success. Th e shiny cowbird Molothrus bonariensis is an extreme generalist brood parasite that uses hosts with a wide range of body masses. Survival of cowbird chicks decreases with host body mass, as competition for food with nestmates is more intense in large than in small hosts. We studied ...

Oriental liver fluke (Clonorchis sinensis) infection was surveyed among residents of Hamyang-gun, Gyeongsangnam-do, Korea during the period of January 2001 to March 2002. Total 1,041 stool samples were collected from residents who visited Public Health Center and its branches in Hamyang-gun and examined using formalin-ether sedimentation method. The overall egg positive rate was 16%, male showi...

In the time of Galen (13I-20I) the vacant spaces between the cornea and the lens were assumed to be filled with a viscid fluid resembling the white of an egg. It was believed that this tissue-the lens, iris, and cornea-forming the boundary of these spaces was kept from desiccating by this fluid medium. This assumption prevailed for nearly I 300 years until Andreas Vesalius (5 I4-I564) revealed,...

Egg turning behavior is an important determinant of egg hatchability, but it remains relatively understudied. Here, we examined egg turning rates and egg temperatures in Forster's terns (Sterna forsteri). We used artificial eggs containing a data logger with a 3-D accelerometer, a magnetometer, and a temperature thermistor to monitor parental incubation behavior of 131 tern nests. Overall, adul...