Juvenile male M. a. ater cowbirds, who have never heard other male cowbirds sing, develop distinctively different repertoires when housed with M. a. ater females from their own area versus M. a. obscurus females from a distant population. Because female cowbirds do not sing, the differences in the males' songs do not arise through vocal imitation. Here we provide data demonstrating that the son...

Two new species of the Stenus indubius group from China are described: Stenus huapingensissp. n. from Guangxi Province and Stenus zhujianqingisp. n. from Zhejiang Province. Habitus photos and illustrations of diagnostic characters of the new species and two described species, Stenus paradecens Tang & Li, 2005 and Stenus guniujiangense Tang & Li, 2005, are provided.

The model of technical assistance and rural extension services (ATER) institutionalized in Brazil since the 50s 20th century expanded geographically thanks to association with offer credit, widely available subsidized, especially 70s, when organizations called Sibrater system were nationalized. Economic fiscal crises 80s 90s disorganized Sibrater, which collapsed, at same time that private serv...

The air compr8ssor 1~i th spr8.ying wfl.tP-r into cy1 inders can make its power consumption ann discharF,e temperature decrease but the effect of spraying ••ater to power consumption and discharge tempera~ ture is difficu1t to he quantitatively sho••ed 1dth rliffqrent starting condition. This paper establishs a formula to calculate the polytropic expon8nt in ideal compressing processes of spray...

The effect of residual concentrations of organophosphate pesticide chlorpyrifos (Lorsban 4E) on the activity of the acetylcholinesterase enzyme and oxygen : nitrogen ratio in the mussel Aulacomya ater was analyzed. Toxicity tests show a sensitivity to the pesticide in the bivalve estimated at 16 μg L(-1) (LC(50-96 hours)). Concentrations between 0.2 and 1.61 μg L(-1) were able to inhibit signif...

Contaminant exposure can vary between species but primary causes of it are often unclear. In order to estimate heavy metal intake of two sympatric passerines - Ficedula hypoleuca Pall. and Parus ater L. - we studied nestling diet and metal concentrations in prey invertebrates, near the Middle Ural copper smelter and in an unpolluted area. Diet of P. ater contained more Cu, Cd and Zn compared to...

Equity measures can be used as working tools to explore management alternatives for :I \ \ater qualit! system. Several example measures of equity are discussed which proved useful in suggesting nra m;inagsment programs, in identifying critical waste dischargers. in suggesting Lones for grouping dischargers. and for understanding given management programs. The example equity measures were evelua...

© Thinkk/y-studio W ater is essential to life, supporting the food web and habitat for much of Earth’s wildlife. Pesticides often contaminate U.S. waterways and threaten aquatic organisms, from invertebrates (worms, molluscs, insects, and zooplankton) to vertebrates (fish and amphibians), and microorganisms (bacteria, fungi, protozoa, algae, and phytoplankton), as well as those that depend on t...