Polyamine-like effects of cobalt(III) hexaammine on various cyclic nucleotide-independent protein phosphokinase reactions

The chemically inert trivalent ion cobalt(III) hexaammine, Co³⁺(NH₃)₆, was found to exert polyamine-like effects in enhancing certain cyclic nucleotide-independent protein kinase reactions catalyzed by nuclear enzyme preparations from rat ventral prostate or liver. At 1 mM, Co³⁺(NH₃)₆ stimulated chromatin- and also non-histone-protein-associated kinase activities with partially dephosphorylated phosvitin as substrate by 38% and 72% respectively, whereas chromatin-associated kinase-catalyzed phosphorylation of lysine-rich histones was not affected under the same conditions. ³²P incorporation (from γ-³²P-ATP) into endogenous protein substrates of chromatin or non-histone protein fractions catalyzed by their erdogencus kinase activity was increased by 47% and 153%, respectively. These effects of Co³⁺(NH₃)₆ were similar to those produced by 1mM spermine. Autoradiographic analysis of endogenous ³²P-labelled nonhistone proteins revealed similar enhancements of the phosphorylation of several of the same proteins, induced by 1mM spermine or 1 mM Co³⁺(NH₃)₆ or 2mM spermidine. The stimulatory actions of polyamines or Co³⁺(NH₃)₆ were not mimicked by raising the ionic strength by addition of comparable concentrations of NaCl. The effects of 1 mM spermine and of 1 mM Co³⁺(NH₃)₆ tested separately were not additive. Phosphorylation of lysine-rich histones by beef heart cyclic AMP-dependent protein kinase was not affected by polyamines or Co³⁺(NH₃)₆ Various findings hint that the enhancement of cyclic nucleotide-independent kinase-catalyzed phosphorylation of certain protein substrates by spermidine, spermine and Co³⁺(NH₃)₆ is primarily due to interaction of these cations with appropriate protein substrates affecting their conformational status. Further, these effects of polyamines may be a reflection of their cationic charge properties rather than being dependent on any particular conformations assumed by the polyamines.     

Abundance and diversity of surface zooplankton in the Gulf of Aqaba, Red Sea, Egypt

Surface zooplankton were studied in Egyptian coastal watersof the Gulf of Aqaba, from bimonthly samples from July 1994to May 1995. Species diversity, numerical abundance and dynamicswere analysed for each taxon, at six sites, inside three Protectorates.A total of 62 taxa and species were identified. At all sites,copepods were predominant in the standing crop with an averageof 1945 ind. M^–3 and formed {small tilde}75.5%, numerically,of the total zooplankton community. The meroplanktonic larvaeoccupied the second rank and they constituted {small tilde}19.7%of the total zooplankton. Seasonally, the main peak of zooplanktonabundance was recorded in winter (January) with an average of3510 ind. M^–3 while September was characterized by thelowest density (1906 ind. m^–3 The relatively higher diversityvalues were recorded at Ras Mohammed Protectorate and a progressivedecline in diversity was observed northward.     

Pluviantaenia kassalensis n. g., n. sp. (Davaineidae), a new cestode from the Egyptian plover Pluvianus aegyptius (L.) in the Sudan

Pluviantaenia kassalensis n. g., n. sp. (Davaineidae), from the intestine of Pluvianus aegyptius (Charadriiformes, Glareolidae) in the Kassala area of the Sudan, differs from other davaineid cestodes in having an armed scolex with an inflated pseudorostellum terminating in two fan-shaped lobes, in the absence of suckers, the presence of a very large sucker-like genital atrium provided distally with a powerful sphincter, and the presence of a thin-walled cirrus-sac, smaller than the genital atrium, enclosing a robust, armed cirrus. The genital atrium cirrus-sac complex, but not the female organs, may be duplicated bilaterally and/or additional sets may occur in marginal or submarginal positions.     

The effect of humic acid and Na2EDDHA on the uptake of Cu,Fe, and Zn by barley in sand culture

Summary Humic acid affected nutrient uptake differently in sand culture. It generally increased Cu uptake, slightly, though insignificantly, increased Fe uptake and practically had no effect on Zn uptake. Such results agree fairly well with the relative stability of humic acid with these metals.When humic acid was added to sand culture at increasing concentration of the metal, it considerably increased dry weight, Cu uptake and Cu concentration through decreasing its toxicity to plant. With Fe, however, humic acid and Na₂EDDHA slightly increased Fe uptake at lower Fe concentration (30 ppm) but significantly reduced both Fe uptake and Fe concentration in plant at higher concentration of Fe compared to the control treatment. Humic acid reduced Zn uptake and Zn concentration in plant at concentrations of 0.5–1.5 ppm Zn, and guarded against Zn toxicity which developed at higher concentration of Zn when no humic acid was added.     

Optimum growth conditions for Amphidinium carterae Hulburt from eutrophic waters in Alexandria (Egypt) and its toxicity to the brine shrimp Artemia salina

Cultures of a strain of Amphidinium carterae Hulburt isolated from a eutrophic basin in Alexandria were investigated for the optimum growth conditions, including vitamin requirements, the assimilation index and the potential toxicity of this species. A division rate of 2.7 day^–1, was reached on the second and third day under optimum conditions, with and without addition of B₁₂ and biotin. The rate of C₁₄ assimilation per unit chlorophyll ranged from 0.2 to 5.4 mgC.(mg Chla)-1.h^–1 according to the growth conditions and to cell size. As the cell density increased in the cultures, the cell size decreased and their photosynthetic efficiency increased. Toxicity of A. carterae to brine shrimp resulted from grazing and not from membrane diffusion of extracellular toxins.     

The equivalence of neo-Darwinism and Walrasian equilibrium: in defense of <Emphasis Type="Italic">Organismus economicus</Emphasis>

Neo-Darwinism is based on the same principles as the Walrasian analysis of equilibrium. This may be surprising for evolutionary economists who resort to neo-Darwinism as a result of their dissatisfaction with Walrasian economics. As it is well-known, the principle of rationality does not play a role in neo-Darwinism. In fact, the whole (neo-)Darwinian agenda became popular exactly because it expunged the idea of rationality from nature, and hence, from equilibrium. It is less known, however, that the rationality principle is also not central in Walrasian equilibrium analysis. Therefore, if we find that the rationality principle must be central to the analysis of decision making of human and nonhuman organisms, we must advance organomics. Organomics is bioeconomics understood as the use of rational choice to the study of the behavior of human and nonhuman organisms. Organomics offers a different starting point than the one offered by neo-Darwinism.