Showing papers by "Federal University of São Carlos published in 1976"
TL;DR: The composition of the zooplankton and its patterns of seasonal variation for eutrophic and oligotrophic aquatic ecosystems, in tropical regions, may differ significantly from temperate waters.
Abstract: Weekly zooplankton samples were taken during the period February, 1972 to January, 1973 at station III in a shallow and turbulent tropical reservoir (Broa Reservoir, Sao Carlos, Sao Paulo, State-Brazil). The samples were taken by plankton standard net with 68 μ mesh size, and collected through the horizontal hawls during 3 min. Rotifera was the most abundant group with 77.6%; Cladocera 13.6%, and Copepoda 8.7% (adult and naupliae stages). Other forms like Chaoborus larvae and some worms occurred sporadically. The seasonal fluctuation of the total zooplankton was very irregular in warm and rainy season and more stable in the dry and cold season. The composition of the zooplankton and its patterns of seasonal variation for eutrophic and oligotrophic aquatic ecosystems, in tropical regions, may differ significantly from temperate waters.
50 citations
TL;DR: The number of cells per filament of M. italica showed a peculiar pulse-like frequency distribution with peak values at 4, 8, 12 and 16, andidences of the synchronous cell division in this planktonic diatom under natural environment are discussed.
Abstract: A filamentous diatom Melosira italica was collected at the beginning of rainy season from a shallow lake in the tropical savanna region in Brazil. Even the sample taken from surface water contained empty cells in high percentages. The number of cells per filament of M. italica showed a peculiar pulse-like frequency distribution with peak values at 4, 8, 12 and 16. Evidences of the synchronous cell division in this planktonic diatom under natural environment are discussed.
11 citations
TL;DR: The snake plasma, except that from Boa constrictor amarali , showed a single haptoglobin band whose mobility was similar to that of human Hp 1, suggestng that the electric charge is very conservative, and the evidence suggests that the low mobility of Boa Hps are due to polymerization.
Abstract: 1. 1. Plasma from 24 species and subspecies of snakes were examined by starch gel electrophoresis for the presence of haptoglobin. 2. 2. Haptoglobin was found in 17 species. In the remaining 7, no demonstrable haptoglobin was found. 3. 3. No evidence of intra-specific variation was found. 4. 4. The snake plasma, except that from Boa constrictor amarali , showed a single haptoglobin band whose mobility was similar to that of human Hp 1, suggestng that the electric charge is very conservative. 5. 5. Boas showed 3 slowly migrating components. 6. 6. However, the evidence suggests that the low mobility of Boa Hps are due to polymerization.
5 citations
01 Jan 1976
TL;DR: In this article, the authors describe asymptotically autonomous neutral functional differential equations with time-dependent lag and extend the results obtained by Hale and Cooke for retarded equations and by Ize for neutral equations with constant lag.
Abstract: Publisher Summary This chapter describes asymptotically autonomous neutral functional differential equations with time-dependent lag. The aim is to extend, for a system of functional differential equations of neutral type, the results obtained by Hale and Cooke for retarded equations and by Ize for neutral equations with constant lag. Haie considered a more general class of equations and was able to extend the results of Bellman and Cooke by proving that ∫∞ γ (t) dt
3 citations