Stephen A. Reynolds

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We present a description of the last half of embryonic development in the European medicinal leech, Hirudo medicinalis, based entirely on externally visible morphological features, and establish reliably observable stages during that development. Embryogenesis, from the time fertilized eggs are deposited in an eggcase (called a cocoon) to the emergence of(More)
ABSTRACT The ontogeny of behavior in an organism must reflect developmental events in the nervous system, and it thus provides a noninvasive measure of neuronal development. This approach may be particularly fruitful in the medicinal leech because the neuronal basis of several behaviors has been characterized in adult leeches, providing a rich background(More)
Observing the development of behavior provides an assay for the developmental state of an embryo's nervous system. We have previously described the development of behaviors that were largely confined to one or a few segments. We now extend the work to a kinematic analysis of the development of swimming, a behavior that requires coordination of the entire(More)
The discovery of embryonic halos around uranium-rich sites that exhibit very high (238)U/(206)Pb ratios suggests that uranium introduction may have occurred far more recently than previously supposed. The discovery of (210)Po halos derived from uranium daughters, some elliptical in shape, further suggests that uranium-daughter infiltration occurred prior to(More)
ACKNOWLEDGMENTS We thank the Office of Naval Research for earlier support that led to this simulator, and the Applied Physics Laboratory at the University of Washington for support while completing this report. Rex Andrew edited this report, with support from ONR grant ABSTRACT In combination with an appropriate background ocean model, simulations of(More)
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