20 research outputs found
Copper Induced Lysosomal Membrane Destabilisation in Haemolymph Cells of Mediterranean Green Crab (Carcinus aestuarii, Nardo, 1847) from the Narta Lagoon (Albania)
ABSTRACTDestabilisation of blood cell lysosomes in Mediterranean green crabCarcinus aestuarii was investigated using Neutral Red Retention Assay (NRRA). Crabs collected in Narta Lagoon, Vlora (Albania) during May 2014 were exposed in the laboratory to sub-lethal, environmentally realistic concentrations of copper. Neutral Red Retention Time (NRRT) and glucose concentration in haemolymph of animals were measured. The mean NRRT showed a significant reduction for the animals of the treatment group compared to the control one (from 118.6 ± 28.4 to 36.4 ± 10.48 min, p<0.05), indicating damage of lysosomal membrane. Haemolymph glucose concentration was significantly higher in the treatment group (from 37.8 ± 2.7 to 137.8.4 ± 16.2 mg/dL, p<0.05) than in control group, demonstrating the presence of stress on the animals. These results showed thatC. aestuarii could be used as a successful and reliable bioindicator for evaluating the exposure to contaminants in laboratory conditions. NRRA provides a successful tool for rapid assessment of heavy metal pollution effects on marine biota
[email protected]; phone +31 30 2535710; fax +31 30 2540860, www.sron.nl Space Telescopes and Instrumentation
ABSTRACT The EURECA (EURopean-JapanEse Calorimeter Array) project aims to demonstrate the science performance and technological readiness of an imaging X-ray spectrometer based on a micro-calorimeter array for application in future X-ray astronomy missions, like Constellation-X and XEUS. The prototype instrument consists of a 5 x 5 pixel array of TES-based micro-calorimeters read out by by two SQUID-amplifier channels using frequency-domain-multiplexing (FDM). The SQUID-amplifiers are linearized by digital base-band feedback. The detector array is cooled in a cryogenfree cryostat consisting of a pulse tube cooler and a two stage ADR. A European-Japanese consortium designs, fabricates, and tests this prototype instrument. This paper describes the instrument concept, and shows the design and status of the various sub-units, like the TES detector array, LC-filters, SQUID-amplifiers, AC-bias sources, digital electronics, etc. Initial tests of the system at the PTB beam line of the BESSY synchrotron showed stable performance and an X-ray energy resolution of 1.58 eV at 250 eV and 2.5 eV @ 5.9 keV for the read-out of one TES-pixel only. Next step is deployment of FDM to read-out the full array. Full performance demonstration is expected mid 2009
Environmentally relevant concentrations of triclocarban affect behaviour, learning, and brain gene expression in fish
Many chemicals spilled in aquatic ecosystems can interfere with cognitive abilities and brain functions that control fitness-related behaviour. Hence, their harmful potential may be substantially underestimated. Triclocarban (TCC), one of the most common aquatic contaminants, is known to disrupt hormonal activity, but the consequences of this action on behaviour and its underlying cognitive mechanisms are unclear. We tried to fill this knowledge gap by analysing behaviour, cognitive abilities, and brain gene expression in zebrafish larvae exposed to TCC sublethal concentrations. TCC exposure substantially decreased exploratory behaviour and response to stimulation, while it increased sociability. Additionally, TCC reduced the cognitive performance of zebrafish in a habituation learning task. In the brain of TCC-exposed zebrafish, we found upregulation of c-fos, a gene involved in neural activity, and downregulation of bdnf, a gene that influences behavioural and cognitive traits such as activity, learning, and memory. Overall, our experiments highlight consistent effects of non-lethal TCC concentrations on behaviour, cognitive abilities, and brain functioning in a teleost fish, suggesting critical fitness consequences of these compounds in aquatic ecosystems as well as the potential to affect human health