Suchergebnisse

Toxicity and Genotoxicity Testing of Roundup
Glyphosate, in the commercial formulation named Roundup, is a broad spectrum herbicide that is one of the most frequently applied pesticides in the world. However, there has been little evidence of Roundup toxicity or genotoxicity. Genotoxicity of glyphosate was carried out using the Escherichia coli SOS chromotest. The glyphosate-induced dose response in the SOS chromotest suggests that glyphosate possesses genotoxic properties. Glyphosate at a 0.2 g/l concentration in toxicity bioassay caused 50% mortality of Daphnia magna (LD50 after 24 h — 0.22 g/l; after 48 h — 0.19 g/l), but 0.25 — 0.5 g/l — 100% death of organisms (LD100 after 24 h — 0.5 g/l; after 48 h — 0.25 g/l). Our results (E. coli SOS chromotest and daphnia test system) together with recent animal studies and epidemiological reports suggest that glyphosate, especially, Roundup possesses both toxic and genotoxic properties.

This article deals with the problems which are arising in the process of adaptation of immigrants to educational spaces in Ukraine and Latvia upon their arrival in the country of settlement. Among these problems are the differences in educational systems of the output and input countries, difficulties in mastering languages of a learning process in the countries, overcoming misunderstanding in intercultural communication within and outside of schools, unpreparedness of teachers and trainers to face and to solve challenges that are generating by immigrants and the host societies. The discussion is based on the preliminary results obtained during the implementation of the joint Ukrainian-Latvian project "Immigrants in Society: Challenges for Education" sponsored by Ministry of Education and Science of Ukraine and Ministry of Education and Science of Latvia.

Abstract
The aim of this study was to assess sediment quality in the ecoregion Engure, western coast of the Gulf of Riga, by using sediment ecotoxicity tests with amphipods Monoporeia affinis and Pontogammarus robustoides and selected biomarkers (AChE, GST, GR, CAT, MT) measured in Macoma balthica, to represent different types of biological responses reacting to different stressors. Ecoregion Engure sediments are characterised by comparatively low concentrations of heavy metals, and the area could be considered as unpolluted. Ecotoxicity tests of ecoregion Engure sediments did not show statistically significant (> 20% mortality) toxic effects. Survival of test organisms ranged from 83 to 100% and revealed "good quality" of tested sediment. There were no established strong differences between the stations and years regarding biomarkers. The integrated biomarker response index indicated more stressful conditions in station Mērsrags, while MT activity revealed heavy metal pollution in station Engure. In general, heavy metal concentrations, ecotoxicity tests and biomarker responses indicate that the ecoregion Engure is not markedly various and anthropogenically affected.