Spectral atmospheric observations at Nantucket Island, May 7-14, 1981

An experiment was conducted by the National Langley Research Center to measure atmospheric optical conditions using a 10-channel solar spectral photometer system. This experiment was part of a larger series of multidisciplinary experiments performed in the area of Nantucket Shoals aimed at studying the dynamics of phytoplankton production processes. Analysis of the collected atmospheric data yield total and aerosol optical depths, transmittances, normalized sky radiance distributions, and total and sky irradiances. Results of this analysis may aid in atmospheric corrections of remote sensor data obtained by several sensors overflying the Nantucket Shoals area. Recommendations are presented concerning future experiments using the described solar photometer system and calibration and operational deficiencies uncovered during the experiment

Ampelopsis arborea (L.) Koehne

https://thekeep.eiu.edu/herbarium_specimens_byname/19800/thumbnail.jp

Lantana camara L.

https://thekeep.eiu.edu/herbarium_specimens_byname/18899/thumbnail.jp

Vitis aestivalis F.Michx.

https://thekeep.eiu.edu/herbarium_specimens_byname/19801/thumbnail.jp

Cell Rearrangement and Directional Migration in Pronephric Duct Development

The morphology of the directed migration of the pronephric duct rudiment of three vertebrates, the salamander, chick and sturgeon, has been examined by scanning electron microscopy. Of particular interest in this paper are the morphology of the duct tip, the role of cell rearrangement, and the relation of duct extension to somite segmentation. The duct rudiments of all three species have motile cell processes (lamellipodia and filopodia) largely confined to their posterior tips. The salamander and sturgeon embryos extend their duct rudiments by extensive cell rearrangements. A short, wide rudiment is elongated to form a long, thin one. The chick duct rudiment stays about the same width and apparently gains volume by cell proliferation. The salamander duct rudiment\u27s posterior tip is always two somites behind the last formed somite. Both the sturgeon and chick embryo\u27s duct rudiments lie well posterior of the last segmented somite adjacent to segmental plate mesoderm. There is still a close coupling, however, between the posterior progression of the duct rudiments and the advancing wave of somite segmentation

Parthenocissus quinquefolia (L.) Planch.

https://thekeep.eiu.edu/herbarium_specimens_byname/19799/thumbnail.jp

Polypremum procumbens L.

https://thekeep.eiu.edu/herbarium_specimens_byname/20763/thumbnail.jp