First evaluation of novel potential synergistic effects of glyphosate and arsenic mixture on Rhinella arenarum (Anura: Bufonidae) tadpoles

The toxicity of glyphosate-based herbicide (GBH) and arsenite (As(III)) as individual toxicants and in mixture(50:50 v/v, GBH-As(III)) was determined in Rhinella arenarum tadpoles during acute (48 h) and chronic assays (22days). In both types of assays, the levels of enzymatic activity [Acetylcholinesterase (AChE), Carboxylesterase(CbE), and Glutathione S-transferase (GST)] and the levels of thyroid hormones (triiodothyronine; T3 andthyroxine; T4) were examined. Additionally, the mitotic index (MI) of red blood cells (RBCs) and DNA damageindex were calculated for the chronic assay. The results showed that the LC50 values at 48 h were 45.95 mg/L forGBH, 37.32 mg/L for As(III), and 30.31 mg/L for GBH-As(III) (with similar NOEC ¼ 10 mg/L and LOEC ¼ 20 mg/L between the three treatments). In the acute assay, Marking´s additive index (S ¼ 2.72) indicated synergistictoxicity for GBH-As(III). In larvae treated with GBH and As(III) at the NOEC-48h (10 mg/L), AChE activityincreased by 36.25% and 33.05% respectively, CbE activity increased by 22.25% and 39.05 % respectively, andGST activity increased by 46.75% with the individual treatment with GBH and by 131.65 % with the GBH-As(III)mixture. Larvae exposed to the GBH-As(III) mixture also showed increased levels of T4 (25.67 %). In the chronicassay at NOEC-48h/8 (1.25 mg/L), As(III) and GBH-As(III) inhibited AChE activity (by 39.46 % and 35.65%,respectively), but did not alter CbE activity. In addition, As(III) highly increased (93.7 %) GST activity. GBHAs(III)increased T3 (97.34%) and T4 (540.93%) levels. Finally, GBH-As(III) increased the MI of RBCs andDNA damage. This study demonstrated strong synergistic toxicity of the GBH-As(III) mixture, negatively alteringantioxidant systems and thyroid hormone levels, with consequences on RBC proliferation and DNA damage intreated R. arenarum tadpoles.Fil: Lajmanovich, Rafael Carlos. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Saneamiento Ambiental. Cátedra de Ecotoxicología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Peltzer, Paola. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Saneamiento Ambiental. Cátedra de Ecotoxicología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Attademo, Andres Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Saneamiento Ambiental. Cátedra de Ecotoxicología; ArgentinaFil: Martinuzzi, Candela Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Saneamiento Ambiental. Cátedra de Ecotoxicología; ArgentinaFil: Simoniello, María F.. Universidad Nacional del Litoral; ArgentinaFil: Colussi, Carlina Leila. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Saneamiento Ambiental. Cátedra de Ecotoxicología; ArgentinaFil: Cuzziol Boccioni, Ana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Saneamiento Ambiental. Cátedra de Ecotoxicología; ArgentinaFil: Sigrist, Mirna. Universidad Nacional del Litoral; Argentin

Microplastics and plastic additives as contaminants of emerging concern: A multi-biomarker approach using Rhinella arenarum tadpoles

Polyethylene microplastics (PE-MPs), a whitish thermoplastic polymer with numerous applications, is one of the materials most widely used in the industrial sector, whereas tetrabromobisphenol A (TBBPA) is a brominated flame retardant. The aim of this study was to analyze the effects of PE-MPs and TBBPA on Rhinella arenarum tadpoles at the laboratory scale. Tadpoles were chronically exposed (30 days) to four treatments: PE-MPs (60 mg L−1), TBBPA (10 µg L−1), their mixture (PE-MPs + TBBPA), and dechlorinated water as negative control (CO). Biomarkers of enzymatic activity (acetylcholinesterase, AChE; carboxylesterase, CbE; glutathione reductase, GR; and glutathione-S-transferase, GST), hepatic physiological alteration (alkaline phosphatase; ALP activity, and cholesterol; CHOL level), and endocrine disruption through thyroid hormone (T4) levels were assessed. In addition, intestine and liver were histomorphologically evaluated. AChE activity in tadpoles was significantly inhibited after exposure to PE-MPs and TBBPA with respect to CO. In addition, CbE, GR, and ALP activities showed higher values in the mixture of PE-MPs+  TBBPA treatment than in CO, whereas CHOL level was higher in TBBPA and PE-MPs+  TBBPA treatments than in CO. GST activity did not show significant differences between treatments and CO. T4 levels increased significantly in all treatments with respect to CO. The intestinal structure of tadpoles exposed to PE-MPs and PE-MPs+  TBBPA showed signs of mechanical damage. The intestinal wall of tadpoles under PE-MPs, TBBPA and PE-MPs+  TBBPA treatments was thicker than that of CO individuals. The analysis of liver histology demonstrated the hepatotoxicity caused by PE-MPs+  TBBPA. This study provides quantitative evidence of the harmful effects of PE-MPs, TBBPA and their mixture on enzymatic and hormonal activities, and histological evidence of intestinal wall hypertrophy and liver damage of R. arenarum tadpoles

Measurement of jet shapes in top-quark pair events at using the ATLAS detector

A measurement of jet shapes in top-quark pair events using 1.8 fb −1 of pp collision data recorded by the ATLAS detector at the LHC is presented. Samples of top-quark pair events are selected in both the single-lepton and dilepton final states. The differential and integrated shapes of the jets initiated by bottom-quarks from the top-quark decays are compared with those of the jets originated by light-quarks from the hadronic W -boson decays in the single-lepton channel. The light-quark jets are found to have a narrower distribution of the momentum flow inside the jet area than b -quark jets