Attraction of the potential biocontrol agent <Emphasis Type="Italic">Galerucella placida</Emphasis> (Coleoptera: Chrysomelidae) to the volatiles of <Emphasis Type="Italic">Polygonum orientale</Emphasis> (Polygonaceae) weed leaves

Galerucella placida Baly (Coleoptera: Chrysomelidae) is a potential biocontrol agent of the rice-field weed Polygonum orientale L. (Polygonaceae). The volatile organic compound (VOC) profiles from undamaged and mechanically damaged plants, and from plants 12- and 36-h following continuous feeding of female G. placida adults and 2nd instar larvae were identified and quantified by GC–MS and GC-FID analyses. Twenty-four and 21 compounds were identified in volatiles of undamaged and insect feeding plants, respectively; whereas 22 compounds were detected in volatiles of mechanically damaged plants. Decanal and 1-dodecanol were unique to undamaged plants, and linalool was detected in volatiles of undamaged and mechanically damaged plants, but not in volatiles of insect damaged plants. However, the beetles are not attracted by none of these volatile components, when tested individually in Y-shaped glass tube olfactometer bioassays. In all plants, methyl jasmonate was predominant. 1-Undecanol was the least amount in undamaged plants, and plants 12-h after feeding by G. placida adults and larvae; whereas 1-tridecanol was the least abundant in plants 36-h after feeding by G. placida adults and larvae, and mechanically damaged plants. The beetles showed significant preference to the whole volatile blends from plants 12-h after feeding by larvae and plants 36-h after feeding by either larvae or adults compared to those of undamaged plants. Further, G. placida responded to individual synthetic compounds, 3-hexanol, 1-octen-3-ol, nonanal, and geraniol at 7, 1.38, 3.75 and 4.5 µg/25 µL CH₂Cl₂, respectively, and provide a basis for attraction of the potential biocontrol agent in the field.     

Spectrophotometric determination of ferbam (iron(III) dimethyldithiocarbamate) in commercial sample and wheat grains using 4,7-diphenyl-1,10-phenanthroline after extraction into mesityl oxide

A procedure has been developed for the determination of iron(III) dimethyldithiocarbamate by converting it into iron(II)-bathophenanthroline complex, which is then extracted into mesityl oxide in the presence of potassium perchlorate. The absorbance is then measured at 534 nm against a reagent blank. Beer's law is obeyed over the concentration range 0.5-20 microg ml(-1) in the final solution. The method is sensitive, highly selective and can be used for the determination of ferbam in a commercial sample, and in mixtures with various dithiocarbamates (ziram, zineb, maneb, etc.) and in wheat grains.     

Detection of Human Adenovirus,Rotavirus, and Enterovirus in Tap Water and Their Association with the Overall Quality of Water in Karachi,Pakistan

Food and Environmental Virology - Drinking water supplies in the developing world often serve as a biosphere for various organisms. Viral gastroenteritis is a neglected area of research in...     

Self-Reporting and the Design of Policies for Regulating Stochastic Pollution

Existing environmental regulations frequently require firms to self-report their compliance status to regulatory agencies. Using a principal-agent framework, I derive and compare incentive-compatible regulatory policies with and without self-reporting. I find the firm needs to be audited less often when self-reporting is required, but punished more often. The sign and magnitude of the gains from self-reporting depend on the relative size of audit and sanction costs, the accuracy of the regulator′s monitoring technology, and the desired level of abatement effort.     

Geo-based model of intrinsic resilience to climate change: an approach to nature-based solution

A substantial amount of researches have been done on the understanding and assessment of resilience from multiple perspectives, e.g., ecological, social, economic, and disaster management; however, recent international approach is trending toward more systematic and comprehensive risk assessment processes. Pivotal element of such approach is to emphasizing on promoting resilience in the face of climate change impacts. Conceptualization and identification of parameters to assess climate change resilience is one of the remaining challenges that academia is facing. Reviewing the principles of the climate change resilience highlighted in the literature, the goal of this study is to introduce a theoretical model about the climate change resilience concept to facilitate and enhance future climate change resilience-related researches. The model proposed in this study is named as the climate change resilience of place (C-CROP) model, a geo-based model which is designed to assess climate change resilience for any geographic region with an approach to the incorporation of nature-based solution (NBS). C-CROP model considers vulnerability, exposure, sensitivity to climate change on one side; another side is co-benefit, climate proofing, and disservices of proposed NBS. An operational framework of the C-CROP model is also proposed, that allows spatially explicit assessment of climate change resilience in real world by developing an indicator-based framework and comprehensive mapping using the geospatial approach. Therefore, this model includes vulnerability hotspots identification; better understanding of the pathways of resilience; and solutions (i.e., NBS) to infer the impacts and effectiveness of resilience-building interventions.

     

Effect of epibionts on the microdistribution of chlorophyll in corals and its detection by fluorescence spectral imaging

The spatial distribution of chlorophyll in three coral species carrying invertebrate symbionts was determined using spectral imaging techniques. From each pixel of the image, full fluorescence spectral data was obtained as well as comparative ratios of fluorescence. The multipixel fluorescence map and the relative-intensity fluorescence ratios demonstrated a high concentration of chlorophyll a next to the pits of Cryptochirus coralliodytes in Favites halicora. Spectral similarity maps of Goniastrea retiformis infested with Lithophaga lessepsiana and of Millepora dichotoma infested with Savignium milleporum revealed relatively higher chlorophyll concentrations in these two corals next to the symbionts. We hypothesize that the invertebrate symbionts fertilize their immediate surroundings with their excreta, enhancing algal growth. The spectral analysis system used in this study made it possible to distinguish such changes by spatial quantitation of the fluorescence emitted from small surface areas.     

Spatio-temporal variations in water quality of Nullah Aik-tributary of the river Chenab, Pakistan

This study reports the spatio-temporal changes in water quality of Nullah Aik, tributary of the Chenab River, Pakistan. Stream water samples were collected at seven sampling sites on seasonal basis from September 2004 to April 2006 and were analyzed for 24 water quality parameters. Most significant parameters which contributed in spatio-temporal variations were assessed by statistical techniques such as Hierarchical Agglomerative Cluster Analysis (HACA), Factor Analysis/Principal Components Analysis (FA/PCA), and Discriminant Function Analysis (DFA). HACA identified three different classes of sites: Relatively Unimpaired, Impaired and Less Impaired Regions on the basis of similarity among different physicochemical characteristics and pollutant level between the sampling sites. DFA produced the best results for identification of main variables for temporal and spatial analysis and separated eight parameters (DO, hardness, sulphides, K, Fe, Pb, Cr and Zn) that accounted 89.7% of total variations of spatial analysis. Temporal analysis using DFA separated six parameters (E.C., TDS, salinity, hardness, chlorides and Pb) that showed more than 84.6% of total temporal variation. FA/PCA identified six significant factors (sources) which were responsible for major variations in water quality dataset of Nullah Aik. The results signify that parameters identified by statistical analyses were responsible for water quality change and suggest the possibility of industrial, municipal and agricultural runoff, parent rock material contamination. The results suggest dire need for proper management measures to restore the water quality of this tributary for a healthy and promising aquatic ecosystem and also highlights its importance for objective ecological policy and decision making process.     

Identification of the processes controlling groundwater quality in shallow aquifers of Moradabad city,west Uttar Pradesh,India

Environment, Development and Sustainability - Present study has been carried out to identify the processes controlling groundwater quality of Moradabad city, Uttar Pradesh. A total 188 groundwater...     

Antioxidative response of Lemna polyrrhiza L. to cadmium stress

Growth, lipid peroxidation, different antioxidative enzymes and metal accumulation were studied in Lemna polyrrhiza treated with different concentrations (1-40 ppm) of CdSO4. The growth of the plant was slightly enhanced with 1 ppm, while higher concentrations retarted growth and multiplication of fronds, the effect being concentration and dose dependant. Increase in malondialdehyde content was insignificant after the first week but a prolonged exposure led to significant (p < 0.05) increase of about 38% and 45% over the control in 20 and 30 ppm, respectively after four weeks. Catalase (EC 1.11.1.6; CAT) activity increased at low concentration, but it declined to 42% and 54% at 40 ppm after 6 and 30 days, respectively Superoxide dismutase (EC 1.15.1.1; SOD), ascorbate peroxidase (EC 1.11.1.11;APx) and glutathione reductase (EC 1.6.4.2) increased at both low as well at high concentrations, but a prolonged exposure to high concentration of Cd (40 ppm) led to significant (p < 0.05) decline in the mean activities of these antioxidant enzymes. Accumulation of Cd in biomass was concentration and time dependant However at high concentration of 40 ppm, Cd accumulation did not increase significantly (p < 0.05) with time. Increased activities of antioxidant enzymes in Cd treated plants suggest that metal tolerance in L. polyrrhiza might be associated to the changes of antioxidant enzymatic activities.