A field validation of two sediment-amphipod toxicity tests

Ionizing radiation has been applied in several areas of knowledge, among them the study of the radiomodifier activity of natural substances. These substances can modify the cellular response to the damage induced by the radiation. Therefore, this work aimed to evaluate the radiomodifier action of Pityrocarpa moniliformis extract on Biomphalaria glabrata embryos exposed to 60Co gamma radiation. Initially, toxicity tests were performed on the extract against the B. glabrata embryos for the choice of concentration that did not cause death and embryonic malformation. Then, the antioxidant activity of the P. moniliformis extract with flavonoids and phenolic compounds was evaluated by means of the ABTS method. To evaluate the radiomodifier activity of the extract, embryos were selected in the blastula stage and irradiated with 7.5 Gy in a 60Co source (gammacell-Co60). Then, the embryos were exposed for 24 h to the extract of P. moniliformis at a concentration of 250 μg/mL. The results showed that the extract of P. moniliformis presents flavonoids and enzymatic inhibition by ABTS, which demonstrates the presence of antioxidant compounds. However, the tests of the radiomodifier activity did not present radioprotective effect for embryos exposed to ionizing radiation.

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Discussion of the paper 'Predicting the performance of concrete structures exposed to aggressive chemical environments - Field validation' by J. Marchand, E. Samson, Y. Maltais, R. J. Lee and S. Sahu

Materials and Structures ◽

10.1617/14046 ◽

2004 ◽

Vol 37 (271) ◽

pp. 502-504

Author(s):

W. G. Hime

Keyword(s):

Concrete Structures ◽

Field Validation

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Acute and chronic effect of cyaniade on survival rate, behavior, and reproduction of Daphnia sp.

AQUATIC SCIENCE & MANAGEMENT ◽

10.35800/jasm.1.1.2013.1969 ◽

2013 ◽

Vol 1 (1) ◽

pp. 52 ◽

Cited By ~ 1

Author(s):

Melky R Pattiwael ◽

Remy E. P Mangindaan ◽

Rudi Prabowo ◽

Inneke F. M Rumengan

Keyword(s):

Government Regulation ◽

Aquatic Organisms ◽

Standard Test ◽

Toxicity Tests ◽

Zooplankton Organism ◽

Rate Behavior ◽

Negative Impacts ◽

Reproduction Pattern ◽

Acute And Chronic Effects ◽

Ministerial Decree

Cyanide (CN) through leaching process in the gold processing could produce tailings that have negative impacts on the aquatic environment. To determine the acute and chronic effects of cyanide on aquatic organisms, toxicity tests have been conducted in the laboratory using Daphnia sp.This zooplankton organism is recommended by APHA as standard test animals. In this study the test concentrations refer to the Ministerial Decree No. 202 of 2004 and Government Regulation No. 82 of 2001. Cyanide was analyzed as free CN and WADS CN. The result of acute toxicity test using cyanide solution showed that Daphnia could survive a maximum concentration of 0.2 ppm. LC50 values for 24 and 72 hours were 0,59 mg/L and 0,10 mg/l, respectively. The LT50 was found at 42 hours. Daphnia sp. produced different numbers of offspring at different CN concentrations, and changed their reproduction pattern from parthenogenesis to sexual reproduction after exposure to a cyanide concentration of 0.1 ppm for 24 hours© Sianida (CN) melalui proses leaching dalam proses pengolahan emas menghasilkan limbah yang dapat memberi dampak negatif bagi lingkungan perairan. Untuk mengetahui sampai seberapa jauh CN dapat memberi efek akut dan kronis terhadap biota air, telah dilakukan uji toksisitas di laboratorium dengan menggunakan Daphnia sp. Zooplankton ini direkomendasikan oleh APHA sebagai salah satu hewan uji standar. Dalam penelitian ini konsentrasi uji yang dipakai mengacu pada peraturan yang berlaku, yaitu Keputusan Menteri No. 202, Tahun 2004, dan Peraturan Pemerintah No. 82, Tahun 2001. Analisis sianida yang dihitung adalah nilai free CN dan WADS CN. Hasil penelitian uji toksisitas akut dengan menggunakan larutan sianida didapati Daphnia mampu bertahan hidup sampai pada konsentrasi 0,2 ppm dan nilai LC50 berada pada konsentarsi 0,1 ppm serta LT50 pada jam ke 42. Hasil uji efek kronis, Daphnia sp. menghasilkan jumlah anakan yang berbeda pada konsentrasi CN yang berlainan, dan mengalami perubahan pola reproduksi dari partenogenesis menjadi seksual setelah dipaparkan pada kosentrasi sianida 0,1 ppm selama 24 jam©

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