We investigate that the impact of freshwater organism exposed to the salinity environment by the frequent rainfall following climate change. To evaluate the stress response following salinity exposure, we assessed the survival rate, molting success rate, the developmental period and mouthpart deformities in Chironomus riparius. In addition, we measured the molecular responses of biomarker gene, gene expression of heat shock protein 70 (HSP70) in C. riparius exposed to salinity after 96 hour. The C. riparius survival rates were showed on time dependent manner and not observed survival organisms above 15 psu at day 4. The pupation and emergence of C. riparius were not seen above 15 psu, and the molting success rate was less than 20% at 10 psu. The developmental retardation of C. riparius was well observed in the pupation and emergence period and was delayed by 4 days at 10 psu compared to the control and 5 psu. The mouthpart deformities after salinity exposure at 96 or 72 hour were observed at 10 psu and 15 psu. The expression of C. riparius HSP70 level was significantly increased exposure to 5 psu and 10 psu. Thus, salinity has been caused to be various ecotoxicological and molecular stress responses on freshwater organisms similar to harmful substances such as EDCs and so on.

Chironomous is aquatic insect belonging to order Diptera, family Chironomidae. Their larval stage can be found mainly in aquatic benthic environment, hence good model organism to study environmental toxicology assessments and consider as useful bio indicators of contamination of the aquatic environment. In this study, Chironomus Heat Shock Proteins, Cytochrome 450, Glutathione S-transferase, Serine-type endopeptidase gene expressions were compared between polluted field areas (Chironomus plumosus) and under laboratory conditions (Chironomus riparious) to investigate molecular indicators for environmental contaminant stress assessment. Heavy metal (Al, Fe, Mn, Cu, Cr, Zn, Se, Pb, As, Cd) concentrations in sediments collected from three study areas exceeded the reference values. Moreover, HSPs, CYP450 and GST gene expression except SP for C. plumosus showed higher expression than C. riparious gene expression. Similar gene expression pattern was observed in C. riparious that exposed environment waters up to 96 h when compared to C. plumosus exposed to waters that grown in lab conditions. In summary, this comparative gene expression analysis in Chironomous between field and laboratory condition gave useful information to select candidate molecular indicators in heavy metal contaminations in the environment.

Multi-walled carbon nanotube reinforced epoxy composites were fabricated using shear mixing and sonication. The mechanical, viscoelastic, thermal, and electrical properties of the fabricated specimens were measured and evaluated. From the images and the results of the measurements of tensile strengths, the specimens having 0.6 wt% nanotube content showed better dispersion and higher strength than those of the other specimens. The Young's moduli of the specimens increased as the nanotube filler content was increased in the matrix. As the concentrations of nanotubes filler were increased in the composite specimens, their storage and loss moduli also tended to increase. The specimen having a nanotube filler content of 0.6 wt% showed higher thermal conductivity than that of the other specimens. On the other hand, in the measurement of thermal expansion, specimens having 0.4 and 0.6 wt% filler contents showed a lower value than that of the other specimens. The electrical conductivities also increased with increasing content of nanotube filler. Based on the measured and evaluated properties of the composites, it is believed that the simple and efficient fabrication process used in this study was sufficient to obtain improved properties in the specimens.