Diversity of bacterial isolates during full scale rotary drum composting

Bacterial diversity of full scale rotary drum composter from biodegradable organic waste samples were analyzed through two different approaches, i.e., Culture dependent and independent techniques. Culture-dependent enumerations for indigenous population of bacterial isolates mainly total heterotrophic bacteria (Bacillus species, Pseudomonas species and Enterobacter species), Fecal Coliforms, Fecal Streptococci, Escherichia coli, Salmonella species and Shigella species showed reduction during the composting period. On the other hand, Culture-independent method using PCR amplification of specific 16S rRNA sequences identified the presence of Acinetobacter species, Actinobacteria species, Bacillus species, Clostridium species, Hydrogenophaga species, Butyrivibrio species, Pedobacter species, Empedobactor species and Flavobacterium species by sequences clustering in the phylogenetic tree. Furthermore, correlating physico-chemical analysis of samples with bacterial diversity revealed the bacterial communities have undergone changes, possibly linked to the variations in temperature and availability of new metabolic substrates while decomposing organics at different stages of composting.     

Monitoring of Pesticidal Contamination of Farmgate Vegetables from Hisar

Analysis of 84 farm gate samples of seasonal vegetables carried out on GC-ECD and GC-NPD systems equipped with capillary columns by using a multi residue analytical technique revealed that 26% samples contained residues above MRL values. The contamination was mainly with organophosphates followed by synthetic pyrethroids and organochlorines. Among organophosphates, residues of monocrotophos, quinalphos and chlorpyriphos exceeded the MRL value in 23% samples. Residues of monocrotophos were higher than MRL value in 3 samples of brinjal and one sample each of okra, cauliflower and smooth gourd, of chlorpyriphos in 3 samples of cauliflower and 8 of cabbage and of quinalphos in one sample each of okra and cauliflower. Among synthetic pyrethroids, cypermethrin was the major contaminant and its residue exceeded the MRL value in one sample each of brinjal, okra and cucumber. Only aldicarb among the carbamates was detected in potato. The residues of some organochlorines, i.e. HCH, DDT and endosulfan were found in all the samples but did not exceed the tolerence limit.     

Nanocarriers for drug delivery applications

Environmental Chemistry Letters - Nanobiotechnology research has recently provided numerous basic and applied advances in the health sector. Nanocarriers have been developed for efficient drug...     

Influence of activity and salinity on the weight-dependent oxygen consumption of the rainbow trout Salmo gairdneri

Two types of secretory cell have been found in the cement glands of the cypris larva of Balanus balanoides (L.). Histochemical tests show the presence of proteins, phenols and the enzyme polyphenol oxidase in both the glands and secreted cement. It is proposed that cyprid cement is composed of tanned protein, all the components of which are derived from the cement glands.     

Synergistic influences of phase, density, and climatic variation on the dynamics of fluctuating populations

Although ecologists have long recognized that certain mammalian species exhibit high-amplitude, often multiannual, fluctuations in abundance, their causes have remained poorly understood and the subject of intense debate. A key contention has been the relative role of density-dependent and density-independent processes in governing population dynamics. We applied capture-mark-recapture analysis to 25 years of monthly trapping data from a fluctuating prairie vole Microtus ochrogaster population in Illinois, USA, to estimate realized population growth rates and associated vital rates (survival and recruitment) and modeled them as a function of vole density and density-independent climatic variation. We also tested for phase dependence and seasonality in the effects of the above processes. Variation in the realized population growth rate was best explained by phase-specific changes in vole density lagged by one month and mean monthly temperatures with no time lags. The underlying vital rates, survival and recruitment, were influenced by the additive and interactive effects of phase, vole density, and mean monthly temperatures. Our results are consistent with the observation that large-scale population fluctuations are characterized by phase-specific changes in demographic and physiological characteristics. Our findings also support the growing realization that the interaction between climatic variables and density-dependent factors may be a widespread phenomenon, and they suggest that the direction and magnitude of such interactive effects may be phase specific. We conclude that density-dependent and density-independent climatic variables work in tandem during each phase of density fluctuations to drive the dynamics of fluctuating populations.     

Monitoring of Seasonal Vegetables for Pesticide Residues

Market samples (60) of six seasonal vegetables were monitoredduring 1996–1997 to determine the magnitude of pesticidalcontamination. The estimation of insecticide residuesrepresenting four major chemical groups i.e. organochlorine,organophosphorous, synthetic pyrethroid and carbamate, was doneby adopting a multiresidue analytical technique employingGC-ECD and GC-NPD systems with capillary columns. The testedsamples showed 100% contamination with low but measurableamounts of residues. Among the four chemical groups, theorganophosphates were dominant followed by organochlorines,synthetic pyrethroids and carbamates. About 23% of the samplesshowed contamination with organophosphorous compounds abovetheir respective MRL values. More extensive studies coveringdifferent regions of Haryana state are suggested to get a clearidea of the magnitude of vegetable contamination with pesticideresidues.     

Multiresidue analysis of neonicotinoids by solid-phase extraction technique using high-performance liquid chromatography

For routine monitoring of pesticides, a multiresidue analysis through solid-phase extraction technique and using high-performance liquid chromatography (HPLC) in cotton seed cake (CSC) has been developed. Extraction of fortified samples was carried out with aqueous acetone under vacuum. The concentrated extract was loaded onto the solid-phase extraction units, preconditioned with acetonitrile. The extraction units were then washed with hexane and finally eluted with acetonitrile. The pesticide residues were determined using a multiresidue method by reversed-phase HPLC. The average percentage recoveries were found to range between 65.47% and 110% at spiking levels of 10 to 40 mg/kg. The method developed shows a healthy rate of recovery and can successfully be utilized for the extraction and screening of neonicotinoid residues in CSC. The detection limits for imidacloprid, acetamiprid, and thiacloprid using this method were found to be 5, 10, and 20 mg/kg, respectively.     

GIS-based assessment and characterization of groundwater quality in a hard-rock hilly terrain of Western India

The growing population, pollution, and misuse of freshwater worldwide necessitate developing innovative methods and efficient strategies to protect vital groundwater resources. This need becomes more critical for arid/semi-arid regions of the world. The present study focuses on a GIS-based assessment and characterization of groundwater quality in a semi-arid hard-rock terrain of Rajasthan, western India using long-term and multi-site post-monsoon groundwater quality data. Spatio-temporal variations of water quality parameters in the study area were analyzed by GIS techniques. Groundwater quality was evaluated based on a GIS-based Groundwater Quality Index (GWQI). A Potential GWQI map was also generated for the study area following the Optimum Index Factor concept. The most-influential water quality parameters were identified by performing a map removal sensitivity analysis among the groundwater quality parameters. Mean annual concentration maps revealed that hardness is the only parameter that exceeds its maximum permissible limit for drinking water. GIS analysis revealed that sulfate and nitrate ions exhibit the highest (CV?>?30%) temporal variation, but groundwater pH is stable. Hardness, EC, TDS, and magnesium govern the spatial pattern of the GWQI map. The groundwater quality of the study area is generally suitable for drinking and irrigation (median GWQI?>?74). The GWQI map indicated that relatively high-quality groundwater exists in northwest and southeast portions of the study area. The groundwater quality parameter group of Ca, Cl, and pH were found to have the maximum value (6.44) of Optimum Index factor. It is concluded that Ca, Cl, and pH are three prominent parameters for cost-effective and long-term water quality monitoring in the study area. Hardness, Na, and SO₄, being the most-sensitive water quality parameters, need to be monitored regularly and more precisely.