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[Earthworm feces-induced systemic resistance of cucumber against anthracnose].

Pot experiment showed that mixing earthworm feces into soil induced a significantly lower (P < 0.05) cucumber anthracnose than mixing peat, but had no significant difference (P > 0.05) with the treatment of system acquired resistance. The activities of polyphenol oxidase, peroxidase and phenylalanine ammonia-lyase in cucumber leaves treated with and without pathogen were increased in different degrees by mixing earthworm feces, compared with by mixing peat. All these suggested that mixing with earthworm feces could induce the system resistance of cucumber and suppress the plant disease via starting up the recovery enzyme system in plant.

Animals↗

Anthropogenic impacts on the biogeochemistry and cycling of antimony.

Antimony is a potentially toxic trace element with no known biological function. Antimony is commonly enriched in coals, and fossil fuel combustion appears to be the largest single source of anthropogenic Sb to the global atmosphere. Abundant in sulfide minerals, its emission to the atmosphere from anthropogenic activities is linked to the mining and metallurgy of non-ferrous metals, especially Pb, Cu, and Zn. In particular, the geochemical and mineralogical association of Sb with Pb minerals implies that, like Pb, Sb has been emitted to the environment for thousands of years because of Pb mining, smelting, and refining. In the US alone, there are more than 400 former secondary lead smelting operations and worldwide there are 133 Pb-Zn smelters in operation today. Antimony is used in creating and improving dozens of industrial and commercial materials including various alloys, ceramics, glasses, plastics, and synthetic fabrics, making waste incineration another important source of Sb to the environment. Enrichments of Sb in atmospheric aerosols, plants, soils, sediments, as well as alpine and polar snow and ice suggest that Sb contamination is extensive, but there are very few quantitative studies of the geographic extent, intensity, and chronology of this contamination. There is an urgent need to quantify the extent of human impacts and how these have changed with time. The decreasing inventories of anthropogenic Sb with time in peat cores from Switzerland and Scotland suggest that the atmospheric Sb flux may be declining, but there have been too few studies to make any general conclusions. In fact, some studies of sediments and biomonitors in central Europe show little decline in Sb concentrations during the past decades. There is an obvious need for reliable data from well dated archives such as polar snow and ice, peat bogs, and sediments. The air concentrations, extent of enrichment, particle size distribution, and rate of deposition of Sb in urban areas is cause for concern. The natural processes which controlled the Sb flux to the atmosphere in the pre-anthropogenic past are poorly understood. The cumulative amount of anthropogenic Sb in soils has not yet been quantified. The long-term fate of Sb in soils, including weathering and mobilization, has only started to be investigated. However, the limited data available suggests that, in some locations at least, anthropogenic Sb in soils may be more mobile than anthropogenic Pb. Further study of this problem is needed, as well as the chemical speciation of Sb in soil-water-plant-sediment systems, and the implications which this has for human and ecosystem health.

Air Pollutants↗

Removal of nitrogen in different wetland filter materials: use of stable nitrogen isotopes to determine factors controlling denitrification and DNRA.

Laboratory incubations with varying O2 and NO3 concentrations were performed with a range of filter materials used in constructed wetlands (CWs). The study included material sampled from functioning CWs as well as raw materials subjected to laboratory pre-incubation. 15N-tracer techniques were used to assess the rates of denitrification versus dissimilatory nitrate reduction to ammonium (DNRA), and the relative role of nitrification versus denitrification in producing N2O. The N2O/(N2 + N2O) product ratio was assessed for the different materials. Sand, shell sand, and peat sustained high rates of denitrification. Raw light-weight aggregates (LWA) had a very low rate, while in LWA sampled from a functioning CW, the rate was similar to the one found in the other materials. The N2O/(N2 + N2O) ratio was very low for sand, shell sand and LWA from functioning CWs, but very high for raw LWA. The ratio was intermediate but variable for peat. The N2O produced by nitrification accounted for a significant percentage of the N2O accumulated during the incubation, but was dependent on the initial oxygen concentration. DNRA was significant only for shell sand taken from a functioning CW, suggesting that the establishment of active DNRA is a slower process than the establishment of a denitrifying flora.

Biodegradation, Environmental↗

Monitoring of the process of composting of kitchen waste in an institutional scale worm farm.

Vermicomposting provides an alternative method of managing waste that is ecofriendly and cost-effective. The Environmental Technology Centre (ETC) at Murdoch University and St. John of God Hospital (SJOG) signed a Memorandum of Understanding (MOU) to install a vermiculture system in SJOG to treat some of the organic waste generated by the on site kitchen facility. This is an effort made by SJOG to reduce the amount of organic waste sent to landfill each year and to treat the waste on site as part of a recycling/reuse program. The study is aimed at scientifically monitoring vermicomposting process and to understand the optimum management requirements to improve the operation of an institutional scale worm farm. In addition, an experiment was conducted to investigate the suitability of bedding materials: horse manure, cow manure, peat coir, and natural bedding (vermicast). The species of earthworms used in this experiment were Red (Lumbricus rubellus), Tiger (Eisenia fetida), and Blue (Lumbricus excavatus). The pH, temperature, worm population and quality of castings were tested in different beds. Results indicated that vermicast was the best bedding for vermicomposting, and there were no significant difference between the performances of the other three beds. However, it can be concluded that the bedding material of horse manure, cow manure, and peat coir were successfully established well within the experimental period of eight weeks, and cow manure with the lowest C:N ratio produced the best quality bedding. As using vermicast for the initial bedding creates a very high capital cost these organic substrates provide cost-effective alternative. Therefore they would be quite appropriate to initiate an institutional scale worm farm.

Animals↗

[Environmental characteristics of the atrazine in the waters in East Liaohe River Basin].

Based on the field investigation and the Laboratory experiment, and taking the Geographic Information System (GIS) techniques as the key data disposal platform, the spatial and temporal differences and the enrichment characteristics of atrazine in the surface water in East Liaohe River Basin were systematically analyzed, the effect factors on that also were interpreted. The results show that, the average atrazine content in waters in regions with glebe or without glebe were namely 9.71 microg x L(-1) and 8.854 microg x L(-1), and the lower reach of the trunk was formed as the focus filed of the atrazine in waters. July is the month that the water contained the largest atrazine with the maximum content of 18.93 microg x L(-1). The spatial pattern of the atrazine in the waters clearly shows that, the atrazine used in the glebe are endangering the surface waters quality in the whole basin and will worsen the waters environment of East Liaohe River basin. The normalized enrichment index of the atrazine in the surface water related to plant atrazine is 0.605-1.750 with the spatial difference, the right part of the trunk is the continuous region with high index, the left part of the trunk is on the contrary, and the lower reaches is the focus region with high index. The normalized enrichment index of the atrazine in the surface waters related to soil atrazine has the spatial difference same to the index related to soil, however, the region with large index or little index has the scattering features. With respect to the effect of soil on the atrazine in the water, the integrated token index of the low moor peat soil is the largest and the peat moor soil and the paddy soil are the least. With respect to effect of the landscape pattern on the atrazine in the surface waters, the integrated token index will increase with the interaction between patches. With a certain range, the integrated token index will increase with the precipitation and runoff; however, the integrated token index will decrease with precipitation if the precipitation excesses the range.

Atrazine↗

[Estimation of the phylogenetic diversity of prokaryotic microorganisms in Sphagnum bogs with the use of fluorescence in situ hybridization (FISH)].

The microbial population of Sphagnum bogs of northern Russia was analyzed with respect to the presence and cell numbers of representatives of particular phylogenetic groups of prokaryotes by means of in situ hybridization with fluorescently labeled rRNA-targeted oligonucleotide probes with broad detection spectra. The total number of cells that hybridized with universal Archaea- or Bacteria-specific probes varied, in peat samples of different bogs, from 45 to 83% of the number of cells revealed by DAPI staining. Down the bog profiles, the total number of prokaryotes and the fraction of archaea among them increased. Application of a set of oligonucleotide probes showed that the number of microorganisms belonging to such phylogenetic lineages of the domain Bacteria as the phyla Proteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, Acidobacteria, and Planctomycetes constituted, in total, 14.0-26.5% of the number of eubacteria detected in the samples. Among the bacteria identified in the peat samples, the most abundant were representatives of the classes Alphaproteobacteria and Betaproteobacteria and the phyla Acidobacteria, Bacteroidetes, and Actinobacteria.

Archaea↗

[Comparative morphological, ecological, and molecular studies of Aspergillus versicolor (Vuill.) Tiraboschi strains isolated from different ecotopes].

Cultural, morphological, ecological, and trophic properties (growth at different temperatures and on various organic substrates), as well as molecular and genetic peculiarities of Aspergillus versicolor (Vuill) Tiraboschi strains of different origins, were determined. The strains were isolated from different ecotopes (upper horizons of modern soils of several geographic regions, ancient soils and peat, and permafrost). No essential distinctions in cultural and morphological properties were revealed between the strains. Strains obtained from peat of the Aleutian Islands were characterized by the highest radial rates of colony growth. Some variations in the ITS loci of rDNA were observed in strains isolated from different ecotopes; the distinctions were most pronounced (1.7%) in the strain isolated from 100 000-year-old permafrost.

Alaska↗

Influence of organic matter on the effectiveness of mineral fertilizers.

The influence of composted peat on the effectiveness of different doses of mineral fertilizers was studied in model greenhouse experiments with barley of the Pirkka variety cultivated in sand and poorly cultivated sandy-loam soil. It was shown that the use of a large amount of composted peat (10% of the weight of the substrate) contributed under the experimental conditions to a pronounced increase in plant productivity only when increased doses of mineral fertilizers were used (NPK at 0.2 g/kg of substrate). A direct correlation between yields and number of microflora in the rhizosphere was not revealed. Conditions were modeled under which increased yield occurred when development of microflora was poor, while the lowest yields were noted when there was an increase in the number of microorganisms. At the same time, the variants with maximal numbers of microorganisms and size of yields did coincide.

Agriculture↗

Host grooming and the transmission strategy of Heligmosomoides polygyrus.

Grooming behavior may play a part in the transmission of the gastrointestinal nematode, Heligomosomoides polygyrus in the mouse host. After infective larvae are placed on individually housed mice, significantly higher numbers of adult worms were recovered from the small intestine of mice that were allowed to self-groom when compared to infection levels in mice that had been fitted with Elizabethan collars to prevent self-grooming. Larvae placed on a single mouse housed with 3 other untreated mice resulted in all mice in the group becoming infected, suggesting that allogrooming may also be important in parasite transmission. A significantly higher percentage of larvae nictate on rough surfaces such as damp peat moss substrate when compared to smooth surfaces such as 0.5% agarose. Mice exposed to larvae placed on peat moss substrate have significantly higher infection levels when compared to mice exposed to larvae on a 0.5% agarose substratum, suggesting that natural transmission of infective L3 larvae in mice may be dependent on a substratum type that allows nictation behavior. A significantly higher percentage of worms were attracted to mouse urine and mouse and rat epidermal lipids when compared to deionized water controls in an in vitro preference assay, suggesting an attraction to host-specific signals. These results support the hypothesis that transmission of this parasite is an active process involving movement of the infective larvae of H. polygyrus into the host's active space where they are ingested during grooming behavior.

Animals↗

Interaction between fulvic acids of different origins and active oxygen radicals.

Using the spin trapping technique, the interaction between fulvic acids (FAs) of different origins and the active oxygen radicals was studied. The active oxygen radicals under study included superoxide anion (O2.-) produced by xanthine oxidase (XOD) and stimulated polymorphonuclear leukocytes (PMN) of human being and hydroxyl radical (.OH) produced from Fenton's reaction. It has been found that the FAs from both Kaschin-Beck disease (KBD) region and non-KBD region can accelerate the production of .OH and scavenge O2.-. FA from peat can scavenge both O2.- and .OH. The results show that the behavior of KBD and non-KBD FAs differs clearly from peat FA. It has been concluded that the superoxidation damage of KBD induced by FA is mainly due to hydroxyl radical reaction initiated in biological system.

Benzopyrans↗

[The quantitative parameters of the vertical migration of radionuclides in the soils in different types of meadows].

The two-component convective-diffusional model was used for determination of vertical migration parameters of 90Sr [correction of 90Cs] and 137Cs in meadow ecosystems and dependence from meadow type and soil properties was shown. The migration coefficients decrease in the order: peat land, lowland meadows, flood-plain meadows, dry meadows. The ecological half-life in the root zone ranges from 55 to 143 y for dry meadows and from 15 to 21 y for peat lands. Analogous parameters for 90Sr was 30-96 and 13-18 y, respectively. Since 1987 to 1994 the ecological half-life of 137Cs increased by a factor of 1.7-6.0.

Cesium Radioisotopes↗

Assessment of bog-body tissue preservation by pyrolysis-gas chromatography/mass spectrometry.

Flash pyrolysis-gas chromatography/mass spectrometry (py-GC/MS) was used to assess the quality and mechanism of protein preservation in the tissue of Iron Age bog bodies from Lindow, UK, and south-eastern Drenthe, The Netherlands. Abundant pyrolysis products of the fresh skin tissue, including 2,5-diketopiperazines of Pro-Gly, Pro-Ala, Pro-Val, Pro-Pro and Hyp, were readily assigned to specific amino acid or dipeptide moieties. Comparison of the pyrolysates of the bog-body tissues with that of modern samples revealed qualitative similarities suggesting good preservation of the collagen and non-collagenous proteins in the ancient tissues. Examination of the pyrolysates of samples of fresh calf skin, which had been treated with various vegetable tanning agents, clearly revealed markers of non-hydrolysable tannins including 1,2-benzenediol, 1,3-benzenediol and 1,2,3-benzenetriol, although chromatographic quality inevitably diminished with increasing functionalization of the compounds. Such markers were not detected in the pyrolysates of the bog-body tissues. Instead 4-isopropenylphenol, a characteristic pyrolysis product of Sphagnum moss, was detected in both solvent-extracted and base-treated samples of tissue. The presence of 4-isopropenylphenol in the pyrolysates of the bog-body tissues provides evidence that their preservation involves reactions of amino acids with sphagnum acid, and possibly other agents derived from the peat. The study constitutes the first chemical characterization of the pyrolysis products of modern and ancient collagen.

Aged↗

Start-up and the effect of gaseous ammonia additions on a biofilter for the elimination of toluene vapors.

Biotechnological techniques, including biofilters and biotrickling filters are increasingly used to treat air polluted with VOCs (Volatile Organic Compounds). In this work, the start-up, the effect of the gaseous ammonia addition on the toluene removal rate, and the problems of the heat accumulation on the performance of a laboratory scale biofilter were studied. The packing material was sterilized peat enriched with a mineral medium and inoculated with an adapted consortium (two yeast and five bacteria). Start-up showed a short adaptation period and an increased toluene elimination capacity (EC) up to a maximum of 190 g/m3/h. This was related to increased CO2 outlet concentration and temperature gradients between the packed bed and the inlet (Tm-Tin). These events were associated with the growth of the microbial population. The biofilter EC decreased thereafter, to attain a steady state of 8 g/m3/h. At this point, gaseous ammonia was added. EC increased up to 80 g/m3/h, with simultaneous increases on the CO2 concentration and (Tm-Tin). Two weeks after the ammonia addition, the new steady state was 30 g/m3/h. In a second ammonia addition, the maximum EC attained was 40 g/m3/h, and the biofilter was in steady state at 25 g/m3/h. Carbon, heat, and water balances were made through 88 d of biofilter operation. Emitted CO2 was about 44.5% of the theoretical value relative to the total toluene oxidation, but accumulated carbon was found as biomass, easily biodegradable material, and carbonates. Heat and water balances showed strong variations depending on EC. For 88 d the total metabolic heat was -181.2 x 10(3) Kcal/m3, and water evaporation was found to be 56.5 kg/m3. Evidence of nitrogen limitation, drying, and heterogeneities were found in this study.

Ammonia↗

Influence of mixing and water addition on the removal rate of toluene vapors in a biofilter.

The effects of successive mixing (homogenization) of packing material (peat), with or without water addition, on the removal of toluene vapors in a biofilter were studied. Over a period of 50 days, an increase in the Elimination Capacity (EC) of approximately 240% was obtained by successive mixing and water additions. After each mixing, a high EC of toluene was maintained only for a short period of 3-4 days. After this time, decreased biofilter performance was observed, probably associated with the development of dried and/or clogged zones. In the long-term experiments, an attenuation of the EC recovery was observed after successive mixing. In this case, an increase of 110% over 4 months of experiment was obtained. The global reduction of EC over time could be explained by the colonization of the biofilter by filamentous fungi which was facilitated by the mixing of the packing material. The most frequently observed fungi were identified as Scedosporium sp. and Cladosporium sp.

Air Pollution↗

Capillary zone electrophoresis of humic acids from the American continent.

A multicomponent background electrolyte (BGE) was developed and its composition optimized using artificial neural networks (ANN). The optimal BGE composition was found to be 90 mM boric acid, 115 mM Tris, and 0.75 mM EDTA (pH 8.4). A separation voltage of 20 kV, 20 degrees C and detection at 210 nm were used. The method was applied to characterize several humic acids originating from various countries of the American continent: soil (Argentina), peat (Brazil), leonardite (Guatemala and Mexico) and coal (United States). Comparison with humic acids of International Humic Substances Society (IHSS) standard samples was also done. Well reproducible electropherograms showing a relatively high number of peaks were obtained. Characterization of the samples by elemental analysis and UV spectrophotometry was also done. In spite of the very different origins, the similarities between humic acids are high and by matrix assisted desorption/ionization-time of flight (MALDI-TOF)-mass spectrometry it was shown that most of the m/z patterns are the same in all humic acids. This means that humic acids of different origin have the same structural units or that they contain the same components.

Americas↗

Working Group report 4: exposure assessment for biological agents.

This Working Group was assembled to review and evaluate methods currently used to estimate work site exposures to biological agents and to present recommendations on suitable measurement strategies. The current state of exposure assessment was evaluated for environments with organic dust including agriculture, composting, sewage and waste treatment processing, peat moss harvesting and handling, cotton and textile processing, greenhouse work, and grass seed processing. Methods for measurement of microbial contaminants in indoor environments were also considered. Important methods are emerging that use quantitative PCR for assessment of microbial agents. Difficulties exist with optimization of extraction to yield contaminant-free DNA without significant DNA loss. Advances in assays for microbial agents (e.g., endotoxin and glucans) as well as allergens have increased the utility of exposure assessment for these agents. A crucial area for further development is international harmonization of methodologies to reduce interlaboratory variability and to facilitate establishment of exposure guidelines. Endotoxin exposure assessment using the Limulus amebocyte lysate method is a high priority for harmonization because of its importance as a pulmonary inflammatory agent in many occupational settings.

Air Pollution, Indoor↗

Environmental conditions prerequisite for complete limb regeneration in the postmetamorphic adult land-phase salamander, Ambystoma.

Historically, postmetamorphic adult land-phase salamanders have been shown to exhibit minimal to nonexistent limb regeneration. Hence, it has been generally accepted that these forms have lost the intrinsic capacity to regenerate a limb. Due to the experimental protocols used, an alternate explanation is also possible: that this intrinsic capacity cannot be expressed when the salamanders are maintained under adverse laboratory environmental conditions. Therefore, this study addresses two questions: 1) What are the optimal environmental conditions for long-term survival of adult land-phase salamanders; and 2) will complete limb regeneration occur in these salamanders if they are maintained under survival conditions. A mixed population of adult Ambystoma were tested under varying conditions of habitat, temperature, humidity, photoperiod, and food source. Complete limb regeneration was possible in 100% of four species of adult postmetamorphic land-phase Ambystoma salamanders given the proper environmental laboratory conditions of a peat moss and potting soil habitat with a controlled temperature of 25 degrees C +/- 5 degrees C, 70% or greater humidity, a 12/12 light/dark photoperiod, a diet including nightcrawlers released into their respective terraria, and an extended observation time of up to 370 days postamputation (dpa). Regeneration was completed during the following range periods for the adult salamanders: A. annulatum, 324 to 370 dpa; A. maculatum, 255 to 300 dpa; A. texanum, 215 to 250 dpa; and A. tigranum, 155 to 180 dpa.

Ambystoma↗

Fluorescence analysis of photoinduced degradation of ecotoxicants in the presence of humic acids.

The photolysis of humic acids and phenols in water containing humic acids was investigated. Humic acids extracted from peat (Vasuygan Bog, Tomsk Region, Russian Federation) induce the phototransformation of 4-chlorophenol at 365 and 222 nm. Humic acids were characterized by UV-, fluorescence-, IR- and EPR-spectroscopy and laser-induced fluorescence. The influence of humic acids on the phototransformation of phenols in different irradiation conditions was investigated. Comparison of the data on mercury lamp irradiation showed that the most effective phenols degradation was observed under exposure to KrCl* exilamp light (lambda = 222 nm) in the presence of humic acids.

Chlorophenols↗