Histopathological alterations in gill,liver and kidney of common carp exposed to chlorpyrifos

Histopathological alterations in gill, liver and kidney of common carp, Cyprinus carpio, intoxicated with sub-lethal concentrations of chlorpyrifos (O,O,-diethyl-O-3,5,6-trichloro-2-pyridyl phosphorothioate) pesticide (1 and 100 μg/L) for a period of 14 days were analyzed under light microscope. Gill exhibited hyperplasia and hypertrophy of gill epithelium, blood congestion, dilation of marginal channel, epithelial lifting, lamellar fusion, lamellar disorganization, lamellar aneurysm, rupture of the lamellar epithelium, rupture of pillar cells and necrosis. Alterations in hepatocytes were more pronounced, including nuclear and cellular hypertrophy, cellular atrophy, irregular contour of cells and nucleus, cytoplasmic vacuolation, cytoplasmic and nuclear degeneration, cellular rupture, pyknotic nucleus, necrosis and melanomacrophages aggregations. Histopathological lesions in kidney were cellular and nuclear hypertrophy, narrowing of tubular lumen, cytoplasmic vacuolation, hyaline droplet degeneration, nuclear degeneration, occlusion of tubular lumen, tubular regeneration, dilation of glomerular capillaries, degeneration of glomerulus and hemorrhage in Bowman's space. The most significant conclusion drawn from this study was that with the increased concentration and duration the toxicosis of chlorpyrifos would be enhanced as shown through the analysis of mean assessment value (MAV) and degree of tissue changes (DTC) also.     

Estimation of Vegetation Coverage in Semi-arid Sandy Land Based on Multivariate Statistical Modeling Using Remote Sensing Data

The estimation of vegetation coverage is essential in the monitoring and management of arid and semi-arid sandy lands. But how to estimate vegetation coverage and monitor the environmental change at global and regional scales still remains to be further studied. Here, combined with field vegetation survey, multispectral remote sensing data were used to estimate coverage based on theoretical statistical modeling. First, the remote sensing data were processed and several groups of spectral variables were selected/proposed and calculated, and then statistically correlated to measured vegetation coverage. Both the single- and multiple-variable-based models were established and further analyzed. Among all single-variable-based models, that is based on Normalized Difference Vegetation Index showed the highest R (0.900) and R ² (0.810) as well as lowest standard estimate error (0.128024). Since the multiple-variable-based model using multiple stepwise regression analysis behaved much better, it was determined as the optimal model for local coverage estimation. Finally, the estimation was conducted based on the optimal model and the result was cross-validated. The coefficient of determination used for validation was 0.867 with a root-mean-squared error (RMSE) of 0.101. The large-scale estimation of vegetation coverage using statistical modeling based on remote sensing data can be helpful for the monitoring and controlling of desertification in arid and semi-arid regions. It could serve for regional ecological management which is of great significance.     

A regularity in trace element contents of marine zooplankton species

Four zooplankton species, three Arthropoda and one Chaetognata, from the Sea of Japan were analyzed in 1984 for eight major and fifteen trace elements, mainly by instrumental neutron activation analysis. Major and trace element contents on a dry weight basis varied little within a factor of 3.7, except for Ca (a factor of 5.7) among the four species. A log-log linearity with a slope of almost-1 was observed between mean oceanic residence time calculated from the mean dissolved river-water input _R and the concentration factor with respect to mean seawater concentration (CF _SW )for each species. The products of _R and CF _SW were nearly constant within a factor of 10, except for Br and Sb over seven orders of variation of CF _SW for each zooplankton species. It demonstrates a new regularity in trace element contents of marine zooplankton species. This relationship leads to the conclusion that the concentration factors of elements for these zooplankton species with respect to elements for these zooplankton species with respect to mean dissolved river-water concentration (CF _RW )are nearly constant within a factor of 10 with average values of 2.98 to 3.43 in logarithm.     

Production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from various carbon sources by batch-fed cultures ofAlcaligenes eutrophus

Copolyesters of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) were produced at 30°C from various carbon sources byAlcaligenes eutrophus under batch-fed growth conditions. The production of P(3HB-co-3HV) from butyric and pentanoic acids was effective under nitrogenlimited conditions, and the conversion of carbon sources into copolyester was as high as 56 wt% at a C/N molar ratio of 40. In contrast, under excess-nitrogen conditions (C/N<10), cell growth was good, while P(3HB-co-3HV) production was partially inhibited. The production of P(3HB-co-3HV) from fructose and propionic acid was almost completely inhibited under excess-nitrogen conditions.