Frogs, toads, and salamanders are well known for harboring an array of distasteful (and poisonous) secondary metabolites, presumably as antipredator defenses; yet few experiments have rigorously demonstrated the efficacy of amphibian chemical defenses against ecologically relevant consumers. For example, despite an absence of rigorous statistical evidence showing their distastefulness to predators, eastern newts (Notophthalmus viridescens (Rafinesque))--a common salamander in lentic North American habitats--are assumed to tolerate diverse predator assemblages because newts secrete tetrodotoxin (TTX), a neurotoxin. Here we combine laboratory and field-based ecology with bioassay-guided separation of chemical extracts to show that eastern newts--although chemically protected against ecologically important consumers in lentic systems--nonetheless suffer substantial predation when tethered in the field. When offered newts with alternative prey (paedomorphic Ambystoma talpoideum), red swamp crayfish (Procambarus clarkii) and largemouth bass (Micropterus salmoides) were 9-10x as likely to feed on A. talpoideum as newts. Additionally, juvenile bluegill (Lepomis machrochirus) were 70% less likely to consume newt eggs compared to control food pellets. We also show that different newt tissues were differentially palatable to predatory fish. All bluegill tested consumed a palatable control food, but only 20% consumed dorsal skin, only 35% ate ventral skin, but 75% fed on newt viscera, suggesting that deterrent metabolites are concentrated in the skin. Bioassay-guided fractionation revealed that crude and water-soluble newt chemical extracts inhibited bluegill feeding, definitively establishing the chemical nature of newt antipredator defenses, although we were unsuccessful at isolating the chemical compounds responsible for unpalatability. Yet, deterrent activity in the polar but not the lipophilic chemical fraction and bioassay results demonstrating that naıve predators rapidly learn to avoid natural concentrations of TTX support the possible role of TTX in suppressing predation on newts. However, when tethered in the field, newt mortality was 55% higher in ponds with predatory fishes than in ponds lacking fishes (62% vs. 40% respectively), indicating the possible existence of other predators that are resistant to (or tolerant of) newt chemical defenses. Together, these results stress the importance of rigorous, ecologically relevant, and hypothesis-driven experimentation to better understand the complexity of chemically- mediated predator-prey interactions, even for well-studied species like N. viridescens.

Dizertační práce Miguel José Cuenca Drouhard ABSTRACT Key words: translation, Czech literature, 20th century, polysystem theory, censorship, history of translation, Čapek, War with the newts History as a scientific tool contributes in a unique manner to the evolution of mankind, its activities and ideas, because mankind, in contrast to things, is formed by its past. In the field of translation studies, History of Translation is perceived as a valuable instrument for understanding the complexity of translation work, and its importance among creative activities and within society in general. Among theories concerning human activities and translation in particular, polysystem theory is characterised by a descriptive and systemic approach that is rooted in Russian formalism and Czech structuralism. Polysystem theory emphasises the dynamic and heterogeneous nature of systems as opposed to the static, homogenous and ahistorical nature of systems which has wrongfully been attributed to the structuralists. Translation activities and its products are mainly part of the target culture's polysystem, because the translation process culminates in the target culture with the final reception and interpretation of the original work, in which in this phase the repertoire of the target system is incorporated. Despite the...

The present Master's thesis handles the reception of the works of Karel Čapek in the Soviet Union and Russian Federation from the 1920s to present day. The focus of the thesis involves two existing Russian translations of Karel Čapek's fantastic novel War with the Newts, published nearly 80 years apart. The paper attempts to demonstrate how Čapek's works were received by the Russian speaking community and in what context they were understood. It shows a picture of the author created by Soviet and Russian journalism and commentaries accompanying his works published in the Russian language. Through the analysis of these texts the thesis demonstrates the influence of ideology on the interpretation of the author's literary work in general, and the novel in particular, and also on the interpretation of his political involvement and his life. Further focus is given to the translation of Czech cultural facts in a selected representative sample of the novel War with the Newts and a comparative analysis of both Russian translations of the sample are made. The Annex contains the interview with A. E. Bobrakov-Timoshkin who was the last translator of the novel. Key words: Karel Čapek, War with the Newts, A. S. Gurovich, A. E. Bobrakov- Timoshkin, the picture of the author, translatological analysis,...

No description available.

No description available.