Effect of Water Variables On Lead Tolerance in Postlarvae of Penaeus Indicus (H. Milne Edwards)

Lead tolerance in Penaeus indicus post-larvae (PL) was studied in relation to the water variables: salinity, temperature and pH. the LC₅₀ for 96 hrs was 7.22 ppm at ambient conditions of salinity (20%_o), temperature (29°C) and pH (7.2). the post-larvae were found to be sensitive to salinity variations with a significant (P < 0.05) low LC₅₀ values at lower (2%_o) and higher (29%_o) ranges. Though a decrease in LC₅₀ value was observed both at higher (45°C) and lower (10°C) temperatures, it was significantly (P < 0.05) low only at higher temperature indicating more toxicity. the LC₅₀ values also showed a significant (P < 0.05) decrease in acidic (pH 2.8) and alkaline (pH 11.0) conditions. the data indicate that lead toxicity increases in the PL of P. indicus with variations in the water variables.     

Cobalt induced changes in immune response and adenosine triphosphatase activities in rats

Abstract

The immuno‐biochemical effects of cobaltous chloride in rats receiving iron‐sufficient and deficient diets were investigated. Rats receiving 100 ppm or more cobalt showed a significant reduction in thymus and body weights along with a marked decrease in hemoglobin, hematocrit, sheep agglutinins and plaque forming cells. These effects were more pronounced in rats receiving cobalt mixed with iron‐deficient diet than those fed on iron‐sufficient diet. The Na⁺‐K⁺ and mitochondrial (Oligomycin‐sensitive) Mg²+ATPase activities in brain and liver of rats fed with iron‐deficient diets were decreased significantly. However, the ATPase activities in these tissues from rats fed with cobalt mixed with iron‐sufficient diets were not altered.     

Geochemistry of the suspended sediment in the estuaries of the Mandovi and Zuari rivers, central west coast of India

The geochemistry of the suspended particulate matter (SPM) collected during the monsoon was determined to identify the sources of SPM and to understand the physicochemical processes in the Mandovi and Zuari river estuaries. The concentrations of SPM decrease seaward in both estuaries, but are relatively high at bay stations. Kaolinite is the most dominant clay mineral in the upstream of both rivers. Smectite increases seaward in both estuaries and is abundant in the bay. Upstream stations of Mandovi, where ore deposits are stored on the shore, exhibit high Fe, Mn, total rare earth elements (∑REE), and middle REE- and heavy REE-enriched patterns. Channel stations of both estuaries exhibit middle REE- and light REE-enriched patterns, which gradually changed seaward to middle REE- and heavy REE-enriched patterns. Canal stations exhibit the highest concentrations of major and trace metals. High metal/Al ratios occur at stations in the upstream of Zuari and at the confluence of canals in the Mandovi estuary. Enrichment factors of metals indicate that Mn is significantly polluted while other metals are moderately polluted. The δ ¹³C and δ ¹⁵N of organic matter indicate that the terrigenous organic matter at the upstream is diluted seaward by marine organic matter. Organic matter at bay stations is largely marine and altered-type. The compositions of SPM are controlled by the particulates from ore dust, the geology of the drainage basins, and the physicochemical processes in the estuaries. Particulates resuspended from the bay are dominated by ore dust, which are advected into the channels of both estuaries during the lull periods of the monsoon.     

Towards cleaner degreasing method in industries: ultrasound-assisted aqueous degreasing process in leather making

Studies on ultrasound-assisted processes are gaining importance due to its effectiveness and facilitating green method in processing. Degreasing of skin/hide prior to tanning process is an important unit operation. Presence of large amounts of natural fat at the interior of skin/hide matrix makes degreasing process a challenging one. Conventionally, organic solvent and/or detergent based degreasing process are employed leading to environmental problems. In the present paper, the use of power ultrasound in aqueous degreasing process has been studied and compared with different degreasing systems. Glutaraldehyde pre-tanning has also been employed for carrying out the degreasing process at ultrasonic bath temperature. The results indicate that there is a significant increase in the degreasing efficiency due to the application of ultrasound. About 2-fold increase in fat removal has been observed due to the use of ultrasound as compared to control under the given process conditions. Comparing the degreasing efficiencies of the solvent with aqueous based ultrasonic processes, about 80% of the solvent degreasing efficiency could be obtained for aqueous degreasing process. This novel ultrasonic process helps in making aqueous degreasing process a viable option, which is eco-friendly even dispensing with temperature control measures.     

STOCHASTIC ANALYSIS OF TIME-AGGREGATED HYDROLOGIC DATA1

Stochastic models fitted to hydrologic data of different time scales are interrelated because the higher time scale data (aggregated data) are derived from those of lower time scale. Relationships between the statistical properties and parameters of models of aggregated data and of original data are examined in this paper. It is also shown that the aggregated data can be more accurately predicted by using a valid model of the original data than by using a valid model of the aggregated data. This property is particularly important in forecasting annual values because only a few annual values are usually available and the resulting forecasts are relatively inaccurate if models based only on annual data are used. The relationships and forecasting equations are developed for general aggregation time and can be used for hourly and daily, daily and monthly or monthly and yearly data. The method is illustrated by using monthly and yearly streamflow data. The results indicate that various statistical characteristics and parameters of the model of annual data can be accurately estimated by using the monthly data and forecasts of annual data by using monthly models have smaller one step ahead mean square error than those obtained by using annual data models.     

Effect of ferrous sulfate on parathion degradation in flooded soil.

In an isotope study, the effect of ferrous sulfate on the degradation of parathion was studied under flooded soil conditions. The addition of ferrous sulfate to flooded soil led to more rapid and extensive degradation of parathion with the formation of additional degradation products in ferrous sulfate-amended soil. This effect was not pronounced when ferrous sulfate was added to non-flooded soil or to flooded autoclaved soil. Sulfate, rather than Fe2+, was implicated in the extensive degradation of parathion.     

Formulation and Characterization of Sodium Alginate g-Hydroxy Ethylacrylate Bio-Degradable Polymeric Beads: In Vitro Release Studies

Novel type of highly swollen beads were prepared by grafting 2-hydroxyethylacrylate onto biodegradable Sodium alginate (SA) via free-radical polymerization using potassium persulphate as an initiator and Triprolidine hydrochloride as a model drug. Evidence of grafting was obtained by fourier transform infrared spectroscopic technique. Morphological properties of the beads were studied by SEM analysis. Thermal properties and crystallinity of the beads were characterized using differential scanning calorimetry and thermogravimetric analysis and X-ray diffraction techniques, respectively. Dissolution experiments were performed to study the release profiles at 37?°C in phosphate buffer solution (pH-7.4). Effect of monomer content, crosslinking agent and drug/polymer ratio on swelling properties and release profiles were also comparatively studied. A dissolution result concludes that drug release decreases with increasing crosslinker content. The highest release (96%) was obtained for the beads prepared with 0.5?mL crosslinking agent. Equilibrium swelling degree also supports the drug release profiles confirming SA-g-HEA beads showed better release profiles compare to plain SA beads.