Kinetics and hydrolysis of fenamiphos, fipronil, and trifluralin in aqueous buffer solutions.

Hydrolyses of fenamiphos, fipronil, and trifluralin were studied in aqueous buffer solutions of pH 4.1, 7.1, and 9.1 at different temperatures, 5, 22 +/- 1, 32 +/- 1, and 50 +/- 1 degrees C. Fenamiphos, fipronil, and trifluralin were found to be more stable in acidic and neutral buffer solutions at temperatures of 5 and 22 +/- 1, and dissipation is rapid at 50 +/- 1 degrees C. In basic buffer and at higher temperature, degradation of fenamiphos was found to be very rapid when compared with fipronil and trifluralin. The rate constants calculated at 32 degrees C for fenamiphos were 2349.4 x 10(-)(8) (pH 4.1), 225.2 x 10(-)(8) (pH 7.1), and 30476.0 x 10(-)(8) (pH 9.1); for fipronil 1750.0 x 10(-)(8) (pH 4.1), 3103.0 x 10(-)(8) (pH 7.1), and 3883.0 x 10(-)(8) (pH 9.1); and for trifluralin 2331.0 x 10(-)(8) (pH 4.1), 2360.0 x 10(-)(8) (pH 7.1), and 3188.0 x 10(-)(8) (pH 9.1). On the basis of rate constant values, these pesticides appeared to be more susceptible to hydrolysis than synthetic organophosphorus compounds such as chlorpyriphos, diazinon, malathion, and ronnel. DT(50) values calculated at 32 degrees C were 228 (pH 4.1), 5310.24 (pH 7.1), and 37.68 (pH 9.1) h for fenamiphos; 608.6 (pH 4.1), 373.9 (pH 7.1), and 270.2 (pH 9.1) h for fipronil; and 502.1 (pH 4.1), 496.8 (pH 7.1), and 355.7 (pH 9.1) h for trifluralin.     

Phenolics and antioxidative activities in narrow-leafed lupins (Lupinus angustifolius L.)

Eight lupin (Lupinus angustifolius L.) genotypes grown at four locations in south central Alberta in 2004 were evaluated for variability in phenolic constituents and antioxidant activity measured by a photochemiluminescence assay. Genotype was the main source of variation for content of phenolic compounds and antioxidant activities. Phenolic compounds in genotypes varied minimally from 11.9 to 14.7 mg catechin equivalent and 4.15 to 4.95 mg rutin equivalent g(-1) lupin for total phenolic and flavonoid contents, respectively. Lupin genotypes exhibited weak antioxidant activity based on water-soluble substances (ACW) of 0.54 to 1.07 micromole Trolox equivalent antioxidant capacities (TEAC)/g with lag time ranging from 70 to 153 s and an antioxidant index of 6.7 to 14.5 and 1.9 to 3.3 micromole TEAC/g based on measurements of lipid-soluble substances (ACL). Antioxidant activity of lupin genotypes was not related to phenolic contents of seeds.     

Chemical and Statistical Analysis of Precipitation in Singapore

The results of chemical analyses of precipitation samples collected in Singapore between August 1997 and July 1998 are presented. Major inorganic and organic ions were determined in 169 rain samples collected using an automated wet-only sampler. The daily sample pH values ranged from 3.49 to 6.54 with a volume-weighted mean of 4.50, and about 88% of the samples had pH values less than 5.0 Nss-SO₄ ^2? accounted for about 53 % of the sum of anions in rain, whereas chloride, nitrate, formate, and acetate accounted for the remainder. Rain chemistry data were analyzed using principal component analysis to find possible sources of the measured chemical species. Three components that accounted for 83.5% of the total variance were extracted: sea-spray (Na⁺, Cl^? and and Mg²⁺) and soil particles (Ca²⁺ and K⁺), acid factor (nss-SO₄ ^2?, NO₃ ^?, NH₄ ⁺, and H⁺), and biomass burning (HCOO^? and CH₃COOO^?).     

Effect of histone acetylation modification with sodium butyrate, a histone deacetylase inhibitor, on cell cycle, apoptosis, ploidy and gene expression in porcine fetal fibroblasts

The present study evaluated the effective dose of sodium butyrate (NaB), a histone deacetylase (HDAC) inhibitor, for determination of the level of enhancement of histone acetylation in porcine fetal fibroblasts (PFFs) based on their morphology, growth, apoptosis and cell cycle status. Cells were analyzed for their histone acetylation levels at H3, H4 and H2A and expression of genes related to histone deacetylation (HDAC1, HDAC2 and HDAC3), pro-apoptosis (Bax and Bak) and anti-apoptosis (Bcl-2). PFFs at passage 3-4 were cultured with 0, 0.5, 1.0, 2.0 and 3.0 mM NaB for 96 h. NaB inhibited cell proliferation at all tested concentrations in a dose-dependent manner. However, there was slow cell growth for PFFs treated with 2.0 and 3.0 mM NaB compared with those of untreated PFFs and those treated with other lower concentrations (0.5 and 1.0 mM). More than 85% of the cells that were untreated or treated with 0.5 or 1.0 mM NaB had intact membranes, whereas, approximately 30% of the cells treated with 2.0 or 3.0 mM NaB had increased cell sizes and a more flattened and elongated appearance. NaB induced apoptosis in a dose-dependent manner; the rates of apoptosis were 2.5 +/- 0.4% for 1.0 mM NaB, 7.6 +/- 1.1% for 2.0 mM NaB and 11.2 +/- 1.4% for 3.0 mM NaB. The chromosomal sets of PFFs treated with 0.5 and 1.0 mM NaB were normal, whereas a lower proportion of PFFs treated with 2.0 and 3.0 mM were classified as normal. NaB at 0.5 and 1.0 mM showed little effect on cell cycle. However, 2.0 and 3.0 mM resulted in an increased cell population at the G(0)/G(1) phase. Increased NaB concentrations led to elevated acetylation of H3, H4 and H2A. NaB altered the expression of histone deacetylation and apoptosis-related genes. In conclusion, 1.0 mM NaB induced histone hyperacetylation in the PFFs and produced less deleterious effects than other concentrations; these PFFs might serve as suitable donors for porcine somatic cell nuclear transfer (SCNT).     

Effects of oral administration of antioxidant taurine on haematological parameters in Wistar rats

The present study evaluates the effects of oral administration of taurine on haematological parameters in normal wistar rats. Tissue oxidative stress is implicated in pathogenesis of various clinical disorders and antioxidant taurine is emerging as prophylactic and therapeutic agent. However, studies on effects of taurine on normal physiology are not reported in literature. Normal saline (Group I) or 5% taurine in normal saline was administered in dose of 50 mg (Group II), 250 mg (Group III) or 500 mg kg(-1) of b.wt. (Group IV) through intragastric intubation for 60 days. The blood cell counts, haemoglobin content, packed cell volume, blood indices, bleeding time and clotting time were estimated using routine laboratory haematological techniques. Neutrophil's phagocytic activity was determined by nitroblue tetrazolium reduction test; serum lysozyme activity was estimated colorimetrically by the degree to lyse bacterial cell suspension and serum taurine levels were estimated by HPLC fluorimetric technique. Platelet count showed a decrease in Group III and IV when compared with Group I and II (p<0.001). Mean corpuscular haemoglobin of Group III and IV are significantly lowered when compared to Group I (p<0.001). A statistically significant decrease was observed in the mean corpuscular haemoglobin concentration between Group 1 and Group IV (p<0.001). The neutrophil percentage of Group II, Group III and Group IV showed a significant increase over Group I (p<0.001). The percentage of lymphocytes showed a significant decrease in Group II, III and Group IV when compared to Group I (p<0.001). Neutrophil's phagocytic activity is significantly lowered in Group III and IV when compared to Group I (p<0.001). The serum lysozyme activity of Group III and IV showed a significant increase over Group I (at p<0.001). From the present study it may be concluded that long term oral administration of taurine affects normal haematological functions.     

Influence of tool angles and speed on the soil reactions of a bent leg plough in two soils

The soil reactions of bent leg ploughs, as influenced by tool angles, need to be studied in detail in order to optimise their performance under different soil and operational conditions. In a field study conducted at Kumulur, south India, three bent leg tool models, with 30°, 37.5° and 45° bend angles, were tested for their soil reactions in a Typic Ustocrept (loamy sand) and a Typic Chromustert (clay loam) soil, under different speeds of operation and rake angles. A simple and reliable instrumentation system, capable of measuring the soil reactions of the tools, was developed and used in this study. Mathematical response models were built on these soil reactions to optimise the parametric levels yielding maximum performance. It was found that the tool, while working in the Ustocrept (loamy sand) and Chromustert (clay loam) soils, should have a rake angle between 9° and 15° for minimum horizontal and lateral soil reactions, and maximum downward suction, aiding penetration.     

Zero-water exchange shrimp farming systems (extensive) in the periphery of Chilka lagoon, Orissa, India

The extensive zero-water exchange shrimp farming system in the periphery of Chilka lagoon (Orissa, India) was studied. The study aimed to describe this unique farming system with special reference to dynamics of macrozoobenthos, production characteristics and economics. The study conducted was based on a general survey as well as monitoring of five individual farms over a complete production cycle. The farming practice in this area is characterized by complete absence of water exchange during rearing. Ponds in this area are generally shallow (mean 72 cm). Most of the water and soil quality characteristics of these farms are within acceptable levels. Macrozoobenthos belonging to 12 taxa were collected, amphipods (81%) and polychaetes (13%) being most numerous. Overall macrobenthic density of farms studied varied from 968 to 11,470 individuals/m² with a gross mean of 5644 individuals/m². There was no general pattern to the variation in abundance of various taxa in different phases of the rearing cycle, suggesting a low predatory pressure by shrimp in the farms studied. Shrimp production was highly variable (91–250 kg/ha), but generally low with a mean of 145 kg/ha. The net income of these farms was estimated to be Rs. 63,250 per crop per ha. Compared with shrimp farming system with regular water exchange in the same area, Chilka farms generated high benefit-cost ratio indicating high profitability and sustainability.     

Toxic and Sublethal Effects of Ammonium Chloride on a Freshwater Fish Oreochromis mossambicus

The effects of ammonium chloride on survival and feeding energetics of the freshwater fish Oreochromis mossambicus were studied. At a concentration of 600 mg L^-1 ammonium chloride, 100% mortality was observed within 24 h; no mortality occurred at 400 mg L^-1 within 96 h; Concentration of 450 mg L^-1 ammonium chloride was found as median lethal concentration at 96 h exposure. Rearing the fish in increasing sublethal concentrations of ammonium chloride, it was found that the feeding rate decreased from 20.309 ± 0.506 mg g live fish^-1 day^-1 (mg g^-1 d^-1 (control) to 11.594 ± 0.479 mg g^-1 d^-1 at the highest sublethal concentration (100 mg L^-1. Growth rate was drastically reduced.