Phosphine in various matrixes

Matrix-bound phosphine was determined in the Jiaozhou Bay coastal sediment,in prawn-pond bottom soil,in the eutrophic lake Wulongtan,in the sewage sludge and in paddy soil as well.Results showed that matrix-bound phosphine levels in freshwater and coastal sediment,as well as in sewage sludge,are significantly higher than that in paddy soil.The correlation between matrix bound phosphine concentrations and organic phosphorus contents in sediment samples is disecussed.     

Assessment of Population Dynamics of Specific Strains in Groundwater Bioaugmentation Experiments by Two Different Molecular Techniques

A set of microcosm experiments was performed to understand the behaviour of special degraders in bioaugmentation experiments. In the experiments the following chlorobenzene degraders were used: the genetically modified Pseudomonas putida F1CC, and the two wild-type strains Pseudomonas putida GJ31 and Pseudomonas aeruginosa RHO1. These strains were used at an initial cell density of 10⁵ cells mL^–1 groundwater which had been spiked with 1,2-dichlorobenzene (1,2-DCB), 1,4-dichlorobenzene (1,4-DCB) and, as main contaminant, chlorobenzene (CB). The population dynamics and behaviour of the three special degraders within the groundwater microcosms were studied by single-strand conformation polymorphism (SSCP) analysis of 16S rDNA fragments amplified from directly extracted community DNA and fluorescent in situ hybridization (FISH) with species-specific probes. RHO1 disappeared after 4 days as detected by FISH in contrast to SSCP-detection where RHO1 could be found during the whole incubation time. Whereas GEM F1CC and wild-type strain GJ31 survived the whole incubation for 20 days. With both methods we were able to detect all strains with high specificity among the indigenous microbial community. The data sets obtained from SSCP analysis and FISH were highly correlated. Specific band intensity within the SSCPfingerprints and the cell counts determined by FISH gave a quantitative overview about the introduced strains.     

Die Wirkung von Photooxidantien auf Sommerweizen (Triticum aestivum L. Star)

The effect of short-time fumigation with the peroxidic photooxidants ozone, peroxyacetyl nitrate (PAN), and hydrogen peroxide (H₂O₂) on the gas exchange of wheat leaves was investigated. Two types of experiments are to be distinguished:

1. Fumigation is carried out at atmospheric CO₂ partial pressure (350 μbar) and the assimilation and transpiration rates are followed simultaneously.
2. The alteration of CO₂-response curves by fumigation is determined; from this, characteristic photosynthetic parameters can be calculated.

With this method, statements about the reaction of both photosynthesis as a whole and specific reaction sites within the most important photosynthetic processes are possible. Ozone in concentrations of 260–280 ppb causes a primary perturbation of the photosynthetic apparatus, whereby the carboxylation rate is affected to nearly the same extent as the electron-transport rate.PAN (120 ppb) causes a reduction in the assimilation rate, primarily due to the closing of the stomata. H₂O₂ affects the gas exchange only in concentrations of above 1 ppm, whereby the reduction of the assimilation rate represents an almost pure stomatal effect. All three fumigants cause an increase in the respiration rate, which may point to an activation of detoxification and repair mechanisms.     

Free phosphine from the anaerobic biosphere

The possible liberation of highly toxic and mutagenic phosphine from putrefying media raises the question of its significance as a problem of hygiene. Free phosphine was established by gas chromatography as a universal trace component in gas emitted from the anaerobic biosphere. Sources of phosphine include landfills, compost processing, sewage sludge, animal slurry and river sediments. We detected maximum concentrations in the order of 20 ppb(v/v).     

Effects of ozone on three open-pollinated families of Pinus taeda L. grown in two substrates

Seedlings from three open-pollinated loblolly pine (Pinus taeda L.) families grown in a mixture of commercial peat moss and grade 3 vermiculite (1:3 by volume) or a mixture of mineral soil and peat (1:1 by volume) were exposed to 0, 160 or 320 ppb ozone (O3) for 6h/day, 4 days/week for 8 weeks beginning 12 weeks after transplanting. Before exposures began, seedlings grown in the vermiculite-peat substrate were taller but smaller in diameter than those grown in the mineral soil-peat substrate. After 8 weeks of exposure, seedlings grown in the mineral soil-peat substrate were significantly larger in diameter and total biomass than those grown in the vermiculite-peat substrate. Primary needle and secondary needle injury increased with increasing O3 concentrations. Suppression of diameter growth, shoot weight and root weight was linear as O3 concentration increased. The effect of O3 on height or diameter growth or shoot biomass was not influenced by substrate type; but the suppression of root biomass due to O3 was dependent on substrate, with greater suppression in biomass occurring in the vermiculite-peat substrate. Foliar injury due to O3 was slightly greater in family 8-103, but growth suppression due to O3 was not significantly different among the families. Based on root biomass, response of seedlings to O3 was substrate-dependent.     

Responses to playback of whistle songs and normal songs in male nightingales: effects of song category, whistle pitch, and distance

In most species of song birds, males develop song repertoires of several different songs. Among this variety, different songs may be used differently in communication and, thus, may have different functions. Here we studied vocal responses to playback of structurally different songs in male territorial nightingales (Luscinia megarhynchos). Nightingales have enormous vocal repertoires of about 200 song types. Among these songs, one category, whistle songs, sticks out syntactically and acoustically. Here we tested whether or not male nightingales match whistle songs with whistle songs and, if so, whether they also match the pitch of the broadcast whistles. Furthermore, we also tested if nightingales treat whistle songs as a separate category of songs. We conducted interactive playback experiments on nocturnal song in which each male received three playback treatments that differed in the number of whistle songs broadcast. Males responded differently during playbacks by singing significantly more whistle songs when the playback tapes contained many whistle songs than when they contained no whistle songs. Males also frequently matched the pitch of the broadcast whistle songs. In contrast to responses during playback, after the playback terminated males sang more whistle songs when no whistle songs were broadcast than when many whistle songs were broadcast. These findings suggest that whistle songs have a specific signal value and that nightingales treat them as a special song category. Electronic supplementary material to this paper can be obtained by using the Springer Link server located at http://dx.doi.org/10.1007/s00265-002-0511-1.