Feeding preferences of gammarid amphipods among four species ofFucus

Each of fourFucus species occurring on the Atlantic coast of Canada was presented to two species of gammarid amphipods in no-choice and multiple-choice laboratory experiments. We also measured concentrations of anti-herbivore phlorotannins in each of theFucus species. The study site was Cranberry Cove in Nova Scotia, Canada, and experiments were conducted in 1988. In a multiple-choice experiment,F. vesiculosus was very heavily grazed. Other species were much less affected. In a no-choice experiment,F. evanescens, F. spiralis andF. vesiculosus were eaten at similar rates, whileF. distichus was barely grazed. These results correlate with measurements of phorotannin concentrations in each of the species.F. distichus had much higher concentrations than did the other species (which were not significantly different among themselves). There is no general clear-cut relationship between grazer deterrence and competitive capability within the fucoid guild studied.     

The chelation of metal ions by the acylpolyamine toxins from the web-spider Nephilengys cruentata: effects in the intoxication/detoxification of preys

Summary. Orb-web-spiders present a series of different strategies for prey capture, involving the use of different types of silk for web building, the use of adhesive traps in the webs, the secretion of toxic compounds to the spider’s preys in the adhesive coating of the capture web and the biosynthesis of a wide range of structurally related acylpolyamine toxins in their venoms. The polyamine toxins usually block neuromuscular junctions and/or the central nervous system (CNS) of Arthropods, targeting specially the ionotropic glutamate receptors; this way these toxins are used are as chemical weapons to kill / paralyze the spider’s prey. Polyamine toxins contain many azamethylene groups involved with the chelation of metal ions, which in turn can interact with the glutamate receptors, affecting the toxicity of these toxins. It was demonstrated that the chelation of Ni⁺², Fe⁺², Pb⁺², Ca⁺² and Mg⁺² ions by the desalted crude venom of Nephilengys cruentata and by the synthetic toxin JSTX-3, did not cause any significant change in the toxicity of the acylpolyamine toxins to the model-prey insect (honeybees). However, it was also reported that the chelation of Zn⁺² ions by the acylpolyamines potentiated the lethal / paralytic action of these toxins to the honeybees, while the chelation of Cu⁺² ions caused the inverse effect. Atomic absorption spectrometry and Plasma-ICP analysis both of N. cruentata venom and honeybee’s hemolymph revealed that the spider’s venom concentrates Zn⁺² ions, while the honeybee’s hemolymph concentrates Cu⁺² ions. These results are suggesting that the natural accumulation of Zn⁺² ions in N. cruentata venom favors the prey catching and/or its maintenance in the web, while the natural accumulation of Cu⁺² ions in prey’s hemolymph minimizes the efficiency of the acylpolyamine toxins as killing/paralyzing tool.     

Mobilization of innovation and investment resources for environmental management in Russian federation regions

Investments in environmental management and environmental protection have a decisive influence on the future of a region and its place in the economic development of the country as a whole. In this article, the principal differences between investment in environmental management and the financing of other projects are discussed. It is proven that, at present, the investment policy in the field of environmental protection of a region is oriented primarily toward current results. In such cases, it is possible to achieve only short‐term goals, and ultimately, to miss the prospect of further conservation of resources. Hence, short‐term investments in environmental protection activities and the achievement of rapid results are replaced by the commitment to promising, long‐term strategic growth. This article notes that the most effective form of implementing environmental monitoring is through environmental auditing, as auditing is performed at the expense of customers and does not require public financing. Furthermore, the effects of implementing environmental policies based on the results of environmental auditing can be even more significant than the results achieved under the State's environmental protection measures     

A novel approach for characterization of polycyclic aromatic hydrocarbon (PAH) pollution patterns in sediments from Guanabara Bay, Rio de Janeiro, Brazil

A novel multivariate method based on principal component analysis of pre-processed sections of chromatograms is used to characterize the complex PAH pollution patterns in sediments from Guanabara Bay, Brazil. Five distinct sources of 3- to 6-ring PAHs could be revealed. The harbour is the most contaminated site in the bay, its plume stretches in a South West to North East direction and the chemical profile indicates mainly pyrogenic sources mixed with a fraction of high-molecular-weight petrogenic PAHs. Rio São João de Meriti is the second largest source of PAHs, and introduces mainly a fraction of low-molecular-weight petrogenic PAHs from the western region of Rio de Janeiro. The sites close to the ruptured pipeline at the Duque de Caxias Refinery show a distinctive pollution pattern indicating a heavy petroleum fraction. The method also led to the identification of new potential indicator ratios also involving coeluting peaks (e.g., triphenylene and chrysene).     

Potential control of toxic cyanobacteria blooms with Moroccan seaweed extracts

Environmental Science and Pollution Research - Marine macroalgae are a promising source of diverse bioactive compounds with applications in the biocontrol of harmful cyanobacteria blooms...     

Biogeochemical transformation of greenhouse gas emissions from terrestrial to atmospheric environment and potential feedback to climate forcing

Environmental Science and Pollution Research - Carbon dioxide (CO2) is mainly universal greenhouse gas associated with climate change. However, beyond CO2, some other greenhouse gases (GHGs) like...     

Ultraviolet irradiation of municipal wastewater: Evaluation of effects on organic constituents

A comparison of chromatograms derived from the UV-absorbing and oxidizable constituents present in primary and secondary municipal wastewater effluents indicates that exposure to UV irradiation at disinfection levels results in only slight chemical changes. The most pronounced chemical effects to nonvolatile organic constituents in wastewater effluents have been observed at irradiation levels in excess of those necessary for disinfection. Aliquots of effluents before and after exposure to varying levels of UV irradiation were concentrated by lyophilization prior to liquid chromatographic (LC) analysis. Anion-exchange chromatographic techniques utilizing a modified ultraviolet detector coupled in series with a cerate oxidative monitor provided excellent resolution and sensitivity in the determination of chemical changes occurring in the effluents as a result of exposure to different irradiation levels. The total coliform counts for each irradiated effluent were determined by the membrane-filter technique to evaluate the effectiveness of UV irradiation as a disinfection process for municipal wastewaters. Changes in biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), and total Kjeldahl nitrogen (TKN) at different levels of exposure to UV irradiation are presented. The results of these determinations and the gas chromatography/mass spectrometry data characterizing the observed chemical changes are discussed.     

Environmentalism and elitism: a conceptual and empirical analysis

The frequent charge that environmentalism is elitist is examined conceptually and empirically. First, the concept of elitism is analyzed by distinguishing between three types of accusations made against the environmental movement: (a)compositional elitism suggests that environmentalists are drawn from privileged socioeconomic strata, (b)ideological elitism suggests that environmental reforms are a subterfuge for distributing benefits to environmentalists and/or costs to others, and (c)impact elitism suggests that environmental reforms, whether intentionally or not, do in fact have regressive social impacts.The evidence bearing on each of the three types of elitism is examined in some detail, and the following conclusions are drawn: Compositional elitism is an exaggeration, for although environmentalists are typically above average in socioeconomic status (as are most sociopolitical activists), few belong to the upper class. Ideological elitism may hold in some instances, but environmentalists have shown increasing sensitivity to equity concerns and there is little evidence of consistent pursuit of self-interest. Impact elitism is the most important issue, and also the most difficult to assess. It appears that there has been a general tendency for environmental reforms to have regressive impacts. However, it is increasingly recognized that problems such as workplace pollution and toxic waste contamination disproportionately affect the lower socioeconomic strata, and thus reforms aimed at such problems will likely have more progressive impacts.This is Michigan Agricultural Experiment Station Journal article no. 11508.     

Aerobic oxidation of secondary benzyl alcohols catalyzed by phosphinite-based palladium pincer complexes

Environmental Chemistry Letters - Aerobic oxidation of organic compounds is receiving attention because molecular oxygen is an abundant, cheap and comparatively safe reagent. Several catalyst...