An ecological study of the macrophytic vegetation of the Doodhadhari Lake,Raipur, M. P., India 1. Distribution and seasonal change in aquatic plants

Summary The distribution of aquatic plants in Doodhadhari lake, Raipur, M.P., India was studied by establishing eight stations. Permanent belt transects were run from all these eight stations every month for a year to assess the seasonal change in vegetational composition. Each transect was taken from the shore to the maximum depth. A contour survey was made and the total area during different seasons were determined. The fluctuation of water level was marked almost every fortnight for a year. The percentage frequency and percentage cover of different species were found to exhibit significant changes during different seasons. Except a few submerged aquatic plant species which are perennial all other species appear and disappear as the seasons progress. The perennial species which are not much affected by the seasonal change are heavily eaten by cattles. The pattern of succession has been outlined after evaluating the changes.     

Hormone-responsive survival of mammary gland explants from the pregnant tammar wallaby (Macropus eugenii) in the absence of exogenous hormones and growth factors.

1. The level of beta-lactoglobulin mRNA increased maximally in mammary explants from late pregnant tammars cultured for 3 days in media containing either prolactin or insulin, cortisol and prolactin. 2. The same level of accumulation occurred when explants were first cultured for 4 days in a chemically defined medium with no exogenous hormones, serum or growth factors, suggesting that the tissue remains viable and hormone-responsive during the initial incubation. 3. Mammary explants cultured for 4 days in medium with no hormones demonstrated a progressive increase in the rate of RNA and DNA synthesis suggesting that the tissue is under a positive autocrine/paracrine stimulus.