Water toxicity and cyto-genotoxicity biomarkers in the fish Oreochromis niloticus (Cichlidae)

Micronucleus (MN) and nuclear abnormalities (NA) tests were used as biomarkers in the fish Oreochromis niloticus from a polluted pond in winter, spring and summer. Samples of water column were taken aiming to evaluate physical-chemical parameters and acute toxicity to the microcrustacean Daphnia similis. The pond waters were toxic to D. similis in spring and winter, but this toxicity was not detected in summer. The pond waters presented low levels of dissolved oxygen in spring and summer; higher ammonia concentrations in winter, and high hardness and conductivity. Fish collected at the polluted pond exhibited higher rates of DNA damage, as indicated by increased rates of MN and NA in erythrocytes when compared to the negative control, which were associated to water toxicity and physical-chemical variable. Thus, this study shows that results of water toxicity tests and genotoxic biomarkers in fish may be associated and theses approaches may be used together for the water quality assessment.Keywords: fish, cyto-genotoxicity, pollution, ecotoxicology, water quality

Exploring the Effect of Boarding and Alighting Ratio on Passengers’ Behaviour at Metro Stations by Laboratory Experiments

The objective of this work was to study the effect of the ratio between passengers boarding and alighting on the passengers’ behaviour at metro stations. A mock-up of a vehicle and the relevant portion of the platform was built to run a series of simulation experiments at University College London’s Pedestrian Accessibility and Movement Environment Laboratory (PAMELA). Different scenarios were tested based on the next generation London Underground trains. The scenarios were classified according to different load conditions. Four types of behaviour are described. In most cases boarding is first, and passengers compete for space to enter the train. In the case of alighting, first passengers are faster than the rest of alighters due to the space available on the platform as boarding passengers give way to those who are getting off the train. In addition, alighters form lanes of flow depending on the number of passengers waiting to board the train on the platform. With respect to the train, if the density inside the train is higher than 4 passengers per square metre, then the flow at the doors starts to decrease. More experiments are needed to study the relationship between platform density and boarding and alighting time

Airbrush robotic painting system: Experimental validation of a colour spray model

4noThis research is focused on developing a robotic painting system for artistic and graphic applications by means of an anthropomorphic robot equipped with an airbrush. Firstly, we introduce a mathematical colour spray model, based on a radially symmetric Gaussian distribution of colour intensity within the spray cone. Then, we present an experimental characterization of colour intensity in a spot, by varying the distance between airbrush and target surface and the spraying time. The experimental results of this pilot study validate the paint intensity model and provide the basis for further investigations.reservedmixedScalera, Lorenzo*; Mazzon, Enrico; Gallina, Paolo; Gasparetto, AlessandroScalera, Lorenzo; Mazzon, Enrico; Gallina, Paolo; Gasparetto, Alessandr

Influence of seasonality and pollution on the hematological parameters of the estuarine fish Centropomus parallelus

This study investigated the hematological parameters of the tropical estuarine fish Centropomus parallelus and their use as a non-destructive biomarker for aquatic pollution. Individuals were collected, in summer and winter, at two estuaries, Cananéia (CAN) and São Vicente (SVE), and blood was extracted by caudal puncture. The evaluated parameters were hematocrit (Ht), red blood cells (RBC), Mean Corpuscular Volume (MCV), and the leukocyte (WBC) and thrombocyte counts. Fishes from CAN showed higher values of absolute number of thrombocytes in the summer. The fishes from SVE presented lower values of Ht and MCV in winter. Comparing the hematological parameters of fishes from these two sites, Ht, MCV, WBC and RBC were higher in fishes from SVE in the summer, whereas during the winter, Ht and thrombocytes were higher in animals from SVE. The results allow attributing the changes in the blood of fishes to seasonality and the presence of contaminants