Impact of a power plant cooling system on copepod and meroplankton survival (Bahía Blanca estuary, Argentina)

The impact of a power plant cooling system in the Bahía Blanca estuary (Argentina) on the survival of target zooplanktonic organisms (copepods and crustacean larvae) and on overall mesozooplankton abundance was evaluated over time. Mortality rates were calculated for juveniles and adults of four key species in the estuary: Acartia tonsa Dana, 1849 and Eurytemora americana Williams, 1906 (native and invading copepods), and larvae of the crab Chasmagnathus granulata Dana, 1851 and the invading cirriped Balanus glandula Darwin, 1854. Mean total mortality values were up to four times higher at the water discharge site than at intake, though for all four species, significant differences were only registered in post-capture mortality. The findings show no evidence of greater larval sensitivity. As expected, the sharpest decrease in overall mesozooplankton abundance was found in areas close to heated water discharge.

The American plant migration. The potato. / by Berthold Laufer, Late Curator, Dept. of Anthropology. Prepared for publication by C. Martin Wilbur, Curator, Chinese Archaeology and Ethnology.

v.28(1938)

The Plant world.

v. 6 (1903)

Horti upsaliensis plantæ cultæ 1780-1800.

v. 1 - 2

Horti upsaliensis plantæ cultæ 1780-1800.

v. 4

National list of scientific plant names.

2

National list of scientific plant names.

1

Inventory of seeds and plants imported / U.S. Department of Agriculture, Bureau of Plant Industry.

62-73, 1923-1924

Excreção urinária de 17-Cetoesteroides neutros no cavalo normal e no cavalo castrado

Total urinary neutral 17-steroids were determined in normal and in castrated horses. One liter of a 15-26 hours urine collection was hydrolysed by refluxing with 10% HC1 (v/v) for ten minutes and extracted with peroxyde-free ethyl ether. The extract was purified by washing with saturated NaHCO³ and KOH solutions. One half of the crude neutral fraction was fractionated with Girard's "T" reagent . The Zimmermann reaction was performed both in the ketonic and in the crude neutral extracts, using alcoholic 2.5N KOH and a 60 minutes period for the colour development in the dark. Optical density measuments were made in a grating Coleman Universal Spectrophotometer at 420 mµ and 520mµ; for the crude neutral fraction a colour correction equation was applied. The aliquot fraction used for colorimety was adjusted for keeping optical density measurements within the range 0.2 to 0.7. Androsterone (mp. 184-184.5°C) with an absorption maximum at 290.5 mµ (Beckman Model DU Spectrophotometer) was used as a reference standard. Table I, ilustrates the results obtained. At the 0.05 probability level there is a significant difference among castrated and normal group means (Fischer's "t" test.) when were used the data obtained from the ketonic fractions; in spite of the use of a colour correction applied for inespecific chromogens, the same results could not be obtained with the crude neutral fractions, Since Girard's reagent fractionation is generaly accepted as the best method for correcting the inespecific chromogen interference in the determination of the 17-ketosteroids by the Zimmermann reaction, we emphasize the value of the results obtained with the ketonic fractions. From these results it appears, as occurs in others mammals, that castrated horses show a lower level of urinary 17-ketosteroids excretion than the normal horses. The significance of the horse testis contribution for the neutral urinary steroid metabolites is discussed. Since horse urine has a low androgenic activity, the fractionation of the neutral 17-ketosteroids must be studied more accurately.

Schistosoma mansoni antigenic extracts obtained by different extraction procedures

Solubilization of Schistosoma mansoni antigens was obtained by agitation of adult worms in a 3M KCl solution. The protein contents of the KCl extrats varied from 0.35 to 0.96 mg/ml. Sera from 97 patients with hepatointestinal shistosomiasis and viable eggs in stools from a Brazilian endemic area were studied by immunoelectroomophoresis and Ouchterlony immunodiffusion methods with the KCl extract and with another antigen, obtained by homogenization of adult schistosomes in saline. The rate of positiveness of immunoprecipitation deterctions by immunoelectroomophoresis with the KCl extract was 53.5%. A correlation was verified between methods of detection and extration procedures, resulting in a better association of the extract obtained by agitation in 3M KCl and immunoelectroomophoresis.

Effects of atmospheric carbon dioxide fertilization on biomass and secondary metabolites of some plant species with pharmacological interes under greenhouse conditions

RESUMEN El aumento del CO2 atmosférico debido al cambio global y/o a las prácticas hortícolas promueve efectos directos sobre crecimiento vegetal y el desarrollo. Estas respuestas pueden ocurrir en ecosistemas naturales, pero también se pueden utilizar para aumentar la producción de algunas plantas y de algunos compuestos secundarios. El actual trabajo intenta estudiar los efectos del enriquecimiento atmosférico del CO2 bajo condiciones de invernadero en el crecimiento y la concentración y la composición de metabolitos secundarios de Taxus bacatta, Hypericum perforatum y Echinacea purpurea en condiciones ambientales mediterráneas. La fertilización del CO2 muestra perspectivas interesantes para la mejorara y aplicabilidad de técnicas hortícolas para aumentar productividad de plantas medicinales, a pesar de diferencias claras entre la especie. En general esta técnica promueve aumentos importantes y significativos en producción primaria y, en algunos casos, también en compuestos secundarios. Esto tiene una gran importancia hortícola porque la productividad a nivel de cosecha total aumenta, directamente porque se aumenta la concentración e indirectamente porque se aumenta la biomasa. SUMMARY The increase of atmospheric CO2 due to global change and/or horticultural practices promotes direct effects on plant growth and development. These responses may occur in natural ecosystems, but also can be used to increase the production of some plants and some secondary compounds. Present work tries to study the effects of atmospheric CO2 enrichment under greenhouse conditions on growth and in the concentration and composition of secondary metabolites of Taxus bacatta, Hypericum perforatum and Echinacea purpurea under Mediterranean environmental conditions. CO2 fertilization shows interesting perspectives to increase and improve horticultural techniques in order to increase plant medicinal productivity, in spite of clear differences among the species. In general this technique promotes important and significant increases in primary productivity and, in some cases, also in secondary compounds. This has a great horticultural relevance because the total productivity of this kind of products increase at crop level, directly because concentration is increased and /or indirectly because biomass is increased. RESUM L'augment del CO2 atmosfèric a causa del canvi global i/o a les pràctiques hortícoles promou efectes directes sobre creixement vegetal i el desenvolupament. Aquestes respostes poden ocórrer en ecosistemes naturals, però també es poden utilitzar per a augmentar la producció d'algunes plantes i d'alguns compostos secundaris. L'actual treball intenta estudiar els efectes de l'enriquiment atmosfèric del CO2 sota condicions d'hivernacle en el creixement i la concentració i la composició de metabòlits secundaris de Taxus bacatta, Hypericum perforatum i Echinacea purpurea en condicions ambientals mediterrànies. La fertilització del CO2 mostra perspectives interessants per a la millora i aplicabilitat de tècniques hortícoles per a augmentar productivitat de plantes medicinals, a pesar de diferències clares entre l'espècie. En general aquesta tècnica promou augments importants i significatius en producció primària i, en alguns casos, també en compostos secundaris. Això té una gran importància hortícola perquè la productivitat a nivell de collita total augmenta, directament perquè s'augmenta la concentració i indirectament perquè s'augmenta la biomassa.

Molluscicide activity of the "Avelós" plant (Euphorbia tirucalli, L. ) on Biomphalaria glabrata, the mollusc vector of schistosomiasis

An aqueous solution of the latex of Euphorbia tirucalli collected at sites receiving large amounts of sunlight showed molluscicide action on Biomphalaria glabrata, with LD50 obtained at the concentration of 28,0 ppm and LD90 at the concentration of 85,0 ppm. The toxicity of the product for fish was similar to that of Bayluscide and of copper sulfate used for comparison. However, the wide distribution of the plant, its easy propagation and the simple procedure for extraction of the active substance, which is biodegradable, favor "avelós" as a promising agent in the control of schistosomiasis.