Röntgenreflex-Intensitätsverteilung bei Anwesenheit von Eigenspannungen I. und II. Art

The Science of Nature -     

Biotransformation of metamitron by human p450 expressed in transgenic tobacco cell cultures

In the present investigation, the oxidative metabolism of 14C-labeled metamitron was examined in plant cell cultures of tobacco overexpressing human P450 enzymes CYP1A1 or CYP1A2; special interest was in the aromatic hydroxylation of the herbicide. The oxidative metabolites deaminometamitron (DAM) and 4-hydroxydeaminometamitron (4-HDAM) were found in the untransformed control culture as well as in the transgenic culture. The transgenic cultures, however, exhibited higher turnover rates after 48 h of incubation with 20 microg 14C-metamitron per assay (untransformed: 40%, CYP1A1: 80%, CYP1A2: 100%). Primary metabolite 4-HDAM was partially found in glucosylated form in the transgenic cultures. As minor oxidative metabolites, 6-hydroxyphenyl-3-methoxymethyl-1,2,4-triazine-5(4H)-one and 3-hydroxymethyl-6-phenyl-1,2,4-triazine-5(4H)-one were identified in the transgenic cultures by GC-MS, LC-MS. Additionally, it could be demonstrated that both foreign enzymes (CYP1A1, CYP1A2) also catalyzed the deamination of metamitron. In a large-scale study (up to 400 microg per assay) with the transgenic culture expressing CYP1A2, the high efficiency of this P450 system toward metamitron was demonstrated: turnover of the xenobiotic was almost complete with 400 microg. Since large portions of unglucosylated 4-H-DAM were found, the activity of foreign CYP1A2 apparently exceeded that of endogenous O-glucosyltransferases of the tobacco cell culture. We concluded that in comparison to the nontransformed cell culture, the extent of metabolism was considerably higher in the transgenic cultures. The transgenic cell cultures expressing human CYP1A1 or CYP1A2 are thus suitable tools for the production of large quantities of primary oxidized metabolites of metamitron.     

Quality assured measurements of animal building emissions: gas concentrations

Comprehensive field studies were initiated in 2002 to measure emissions of ammonia (NH3), hydrogen sulfide (H2S), carbon dioxide (CO2), methane (CH4), nonmethane hydrocarbons (NMHC), particulate matter <10 microm in diameter, and total suspended particulate from swine and poultry production buildings in the United States. This paper focuses on the quasicontinuous gas concentration measurement at multiple locations among paired barns in seven states. Documented principles, used in air pollution monitoring at industrial sources, were applied in developing quality assurance (QA) project plans for these studies. Air was sampled from multiple locations with each gas analyzed with one high quality commercial gas analyzer that was located in an environmentally controlled on-farm instrument shelter. A nominal 4 L/min gas sampling system was designed and constructed with Teflon wetted surfaces, bypass pumping, and sample line flow and pressure sensors. Three-way solenoids were used to automatically switch between multiple gas sampling lines with > or =10 min sampling intervals. Inside and outside gas sampling probes were between 10 and 115 m away from the analyzers. Analyzers used chemiluminescence, fluorescence, photoacoustic infrared, and photoionization detectors for NH3, H2S, CO2, CH4, and NMHC, respectively. Data were collected using personal computer-based data acquisition hardware and software. This paper discusses the methodology of gas concentration measurements and the unique challenges that livestock barns pose for achieving desired accuracy and precision, data representativeness, comparability and completeness, and instrument calibration and maintenance.     

Polychlorierte Naphthaline

Measurements show that PCN may occur in industrial waste and residues in the mg/kg range. Investigations were carried out with optimized parameters for GC and MS using two different GC/MS-systems. Chromatograms were obtained for a variety of chlorination degrees using capillary columns of different polarities. It is proposed to quantify PCN using relevant single compounds comparable to the analysis of polychlorinated biphenyls.     

Analytik von Umwandlungsprodukten des Schwefellosts (S-LOST)

The results of investigations of the aquatic ecotoxicity of sternutators and their metabolites (phenyl arsenic compounds) are presented. The standardized luminescence inhibition test (LumisTox, Dr. Lange) with the marine bacteriaVibrio fischeri was applied according to the German norm DIN 38412, part 34. All investigated organic AS(III) compounds exhibit EC₅₀-values (50 % inhibition of the luminescence) of less than 1 mg/l, whereas all investigated organic As(V) compounds and inorganic arsenic show EC₅₀-values exceeding 100 mg/l     

Bionomische Studien an mediterranen Anthozoen: die Anthozoenfauna des Strombolicchio (Äolische Inseln)

Strombolicchio is a rocky islet situated about 1.6 km northeast of the isle of Stromboli. The islet consists of three steep walls having different light and surface conditions. The zonation on the northern wall differs essentially from the zonation found in caves because of the greater turbulence. On smooth rocks near the water surface, there is only one actinian species which resists turbulence, Actinia equina. The best turbulence resisting anthozoan species are the scleractinians (Astroides calycularis Balanophyllia verrucaria). They are followed by stolonial growing forms (Paralcyonium elegans, Cornularia cornucopiae). All other actinians settle in crevices and small holes. The turbulence prevents Parazoanthus axinellae and Corynactis viridis from settling on the smooth rock near the surface. Therefore, these species occur on Strombolicchio only at comparatively deep levels. As a result of being forced to settle in crevices, space competition occurs among the various actinian species. Cereus pedunculatus, Aiptasia mutabilis, and Telmatactis forskalii co-exist, while Anemonia sulcata lives isolated in few crevices only. Contrary to other localities, A. sulcata is not the most abundant actinian species on Strombolicchio. Most frequent are the viviparous forms of Cereus pedunculatus and Actinia equina mediterranea. This mode of reproduction is rather rare in these species in the Mediterranean Sea, but common in the Atlantic Ocean. It is supposed that the viviparous varieties of Strombolicchio are geographical isolates of Atlantic populations. The influence of light on the colour of some anthozoans has also been studied. Zooxanthellae were found to be much more abundant in Aiptasia mutabilis in darkness than in bright surface waters. Gerardia savaglia proved to be quite abundant in deeper caves and on overhanging walls; it is more sciaphilic than Paramuricea clavata. Paralcyonium elegans occurs near the surface as well as at different depth levels; it has been observed in differing growth forms, corresponding to different patterns of turbulence. Alcyonium brioniense is considered to be a growth form of Alcyonium acaule.     

Elbehochwasser 2002 — Ein Rückblick

Objective

Flood sediments were investigated due to the extreme flood situation around Dresden in August 2002

Method

The samples have been analyzed by screening inorganic and organic pollutants.

Results

It was observed that As, Pb, Cd, Zn, Cu, B and other heavy metals as well as DDT, PCB and Benzo [a] pyren were significantly enriched.

Conclusion

Depending on geogenic and anthropogenic impacts, the spatial distribution of these contaminants was different. Organic compounds were dislocated down stream from Czech Republic along the Elbe River. Because of the old ore mining, samples near the Mulde and Wei\eritz Rivers showed high metal pollution.

Perspective

More detailed and systematic investigations should be undertaken in the Elbe and Mulde river systems.     

Multi-year, seasonal genotypic surveys of coral-algal symbioses reveal prevalent stability or post-bleaching reversion

This report documents the extent to which coral colonies show fluctuations in their associations with different endosymbiotic dinoflagellates. The genetic identity of Symbiodinium from six coral species [Acropora palmata (Lamarck), A. cervicornis (Lamarck), Siderastrea siderea (Ellis and Solander), Montastrea faveolata (Ellis and Solander), M. annularis (Ellis and Solander), and M. franksi (Gregory)] was examined seasonally over five years (1998 and 2000–2004) in the Bahamas and Florida Keys at shallow (1 to 4 m) fore-reef/patch reef sites and at deeper fore-reef (12–15 m) locations. Symbionts were identified genetically using denaturing gradient gel electrophoresis (DGGE) fingerprinting of the internal transcribed spacer region 2 (ITS2) of ribosomal RNA gene loci. Repetitive sampling from most labeled colonies from the Bahamas and the Florida Keys showed little to no change in their dominant symbiont. In contrast, certain colonies of M. annularis and M. franksi from the Florida Keys exhibited shifts in their associations attributed to recovery from the stresses of the 1997–1998 El Niño southern oscillation (ENSO) event. Over several years, a putatively stress-tolerant clade D type of Symbiodinium was progressively replaced in these colonies by symbionts typically found in M. annularis and M. franksi in Florida and at other Caribbean locations. Greater environmental fluctuations in Florida may explain the observed changes among some of the symbioses. Furthermore, symbiotic associations were more heterogeneous at shallow sites, relative to deep sites. The exposure to greater environmental variability near the surface may explain the higher symbiont diversity found within and between host colonies.