Interaction of temperature and an environmental stressor: Moina macrocopa responds with increased body size,increased lifespan,and increased offspring numbers slightly above its temperature optimum

For organisms, temperature is one of the most important environmental factors and gains increasing importance due to global warming, since increasing temperatures may pose organisms close to their environmental tolerance limits and, thus, they may become more vulnerable to environmental stressors. We analyzed the temperature-dependence of the water-soluble antioxidant capacity of the cladoceran Moina macrocopa and evaluated its life trait variables with temperature (15, 20, 25, 30 °C) and humic substance (HS) concentrations (0, 0.18, 0.36, 0.90, 1.79 mM DOC) as stressors. Temperatures below and above the apparent optimum (20 °C) reduced the antioxidative capacity. Additions of HSs increased body length, but decreased mean lifespan at 15 and 20 °C. There was no clear HS-effect on offspring numbers at 15, 20, and 30 °C. At 25 °C with increasing HS-concentration, lifespan was extended and offspring numbers increased tremendously, reaching 250% of the control. Although the applied HS preparation possesses estrogenic and antiandrogenic activities, a xenohormone mechanism does not seem plausible for the reproductive increase, because comparable effects did not occur at other temperatures. A more convincing explanation appears to be the mitohormesis hypothesis which states that a certain increase of reactive oxygen production leads to improved health and longevity and, with Moina, also to increased offspring numbers. Our results suggest that at least with the eurythermic M. macrocopa, a temperature above the optimum can be beneficial for several life trait variables, even when combined with a chemical stressor. Temperatures approximately 10 °C above its optimum appear to adversely affect the lifespan and reproduction of M. macrocopa. This indicates that this cladoceran species seems to be able to utilize temperature as an ecological resource in a range slightly above its thermal optimum.     

Bacteriological water quality status of River Yamuna in Delhi

Bacteriological water quality status in terms of total coliform and faecal coliform count was studied on both--east and west banks of river Yamuna in Delhi. Membrane filtration technique was adopted for enumeration of total coliform and faecal coliform count in the river water sample collected on monthly basis for 2 years--2002 and 2003. The study reveals the impact of diverse anthropogenic activities as well as the monsoon effect on the bacterial population of river Yamuna in Delhi stretch. Microbial population contributed mainly through human activities prevailed in the entire stretch of Yamuna river with reduction in bacterial counts during monsoon period due to flushing effect. Bacteriological assessment does not provide an integrated effect of pollution but only indicate the water quality at the time of sampling. Hence, this parameter is time and space specific.     

Effect of kinetin on leaf protein content and its profile in mung bean under salt stress

Application of NaCl resulted in about 67% reduction in amino acid content and 24% reduction in buffer soluble protein content in mung bean [Vigna radiata (L.) Wilczek.] leaf as compared with the control. Gel electrophoretic profile of buffer soluble protein content in leaf of mung bean showed an extra band in between 29 kD and 45 kD in stress protein profile as compared with control. It was noted that the foliar spray of kinetin (6-furfuryl aminopurine) used in the present study was able to overcome up to certain extent the adverse effects of stress caused by NaCl.     

Non-equilibrium thermodynamics of ecosystems: Entropic analysis of stability and diversity

The aim of the paper is first to develop a non-equilibrium thermodynamic model of a multi-species ecosystem. The key to this is the expression of entropy-production (change of entropy) which is equivalent to a well-known expression of Liapunov function used in many problems of ecological and chemical reaction systems. On the basis of the expression of entropy-production we have made an entropic (thermodynamic) analysis of ecological stability (both global and local) including the study of interrelation between ecological diversity and stability. As illustrative examples we have discussed some basic problems of classical and generalized Lotka–Volterra systems.     

Developmental strategies for sustainable ecosystem on mine spoil dumps: a case of study

An important goal of ecological rehabilitation is to accelerate natural successional processes to increase biological productivity, soil fertility and biotic control over biogeochemical fluxes within the recovering ecosystems. A new approach called Microbe Assisted Green Technology (MAGT) is an integrated biotechnological approach developed at National Environmental Engineering Research Institute (NEERI) through exhaustive laboratory as well as field studies and serve as a model for land reclamation and development of lush green vegetation on mine overburdens. One year old seedlings of native tree species were planted on 6.3 ha area of manganese mine overburden at Gumgaon under Manganese Ore India Ltd., Maharashtra, India. Continuous efforts resulted in nutrient rich soil with high N, P, K and organic carbon; well developed biodiversity, including bacteria, fungi, higher plants (more than 350 species) and different classes of animals. Planted trees accumulated 698 t ha( - 1) above ground biomass and 143 t ha( - 1) below ground mass. This was achieved in 18 years by MAGT, which otherwise takes hundreds of years.     

Toxicokinetics,metabolism, and microsomal studies of chlorpropham in rats

A study on the toxicokinetic behavior, metabolism of chlorpropham, and its effect on cytochrome P₄₅₀ from liver microsomes was carried out in albino rats after a single and consecutive oral administration at 500?mg?kg^?1 body weight for 10 and 20 days. Chlorpropham was detected in the blood at 0.08?h (11.43?±?1.72?µg?mL^?1) reaching a maximum concentration at 2?h (30.90?±?2.55?µg?mL^?1) and a minimum at 48?h (1.95?±?0.20?µg?mL^?1) after a single oral administration of 500?mg?kg^?1. The absorption rate constant (K _a) was 0.66?±?0.48?h^?1. The Vd _area (18.01?±?2.78?L?kg^?1) and t _1/2 β (12.23?±?1.96?h) values suggested a wide distribution and long persistence of the compound in the body, respectively. The higher Cl_R (0.82?±?0.00?L?kg^?1?h^?1) compared to Cl_H (0.18?±?0.02?L?kg^?1?h^?1) value indicated that a major portion of chlorpropham was excreted through the urine (30%) compared to the faeces (2.81%). Chlorpropham residue was detected in all tissues of rat at 0.25?h while its metabolite, meta-chloroaniline was detected in liver, kidney, heart, lung, and spleen tissue at 0.25?h. Meta-chloroaniline was not detected in skeletal muscle, brain, fat, and stomach tissue at any time of the observation period. Maximum concentrations of chlorpropham and meta-chloroaniline were detected at 2?h (except in the spleen), and minimum concentrations of chlorpropham at 24 (heart, lung, spleen, skeletal muscle, and stomach) and 48?h (liver, kidney, brain, and fat tissue) respectively; and meta-chloroaniline at 24?h (except heart and spleen). The tissue half-life of chlorpropham in rat varied from 3.80 to 11.60?h. Repeated oral administration of chlorpropham at 500?mg?kg^?1 for 10 and 20 days caused an induction of the liver microsomal pellet of rat.     

Effect of phytohormone pretreatment on metabolic changes in Vigna radiata under salt stress

Efficiency of pretreatment as foliar spray of indole-3-acetic acid, gibberellic acid and kinetin (6-furfuryl aminopurine) each ranging from 10(-7) to 10(-5) M in restoring the metabolic alterations imposed by NaCl salinity (E.C. value 4.0 m mhos/cm) was investigated in Vigna radiata (L.) Wilczek. Application of NaCl resulted in about 7% and 9% decrease in phenol content in mung bean leaf and root respectively. In leaf, NaCl caused 40% increase in polyphenol oxidase enzyme activity over the control set. This effect was accentuated in root, where salinity caused 200% increase in the enzyme activity. In leaf and root of mung-bean plant, ascorbic acid content decreased about 29% and 31% respectively under salinity stress as compared with control. Ascorbic acid oxidase enzyme activity increased under stress by about 55% and 23% respectively in leaf and root. It was noted that all the three growth regulators used in the present study were able to overcome to variable extents the adverse effects of stress imposed by NaCl solution.     

Application of capillary electrophoresis combined with a modified BCR sequential extraction for estimating of distribution of selected trace metals in PM2.5 fractions of urban airborne particulate matter

The capillary electrophoresis (CE) method combined with a sequential extraction was applied to determine the distribution of Fe, Zn, Cu, Mn and Cd in urban ambient air PM2.5 samples. PM2.5 was collected on Teflon filters with dichotomous sampler, and the modified extraction procedure following the BCR leaching procedure was used to chemically fractionate metals into "easily exchangeable" with water, "acid extractable" with 0.11 mol/l acetic acid, "reducible" with 0.1 mol/l hydroxylamine hydrochloride acidified to pH 2.0 with nitric acid, and "oxidisable" with oxidation by 8.8 mol/l hydrogen peroxide (H2O2) followed by extraction with 1.0 mol/l ammonium acetate. Based on the obtained results it was concluded that the application of the studied methodology provides chemical fractionation data that reflect the general sources and potential health hazards of the studied metals.