Identification and quantitative analysis of the amino acids present in protein of the brown shrimp Penaeus aztecus

In order to better formulate an artificial shrimp diet, the protein composition of shrimp was assessed and the essential amino acids determined. Penaeus aztecus were treated to remove lipids, carbohydrates and other interfering substances, and the protein was hydrolyzed to its constituent amino acids. The amino acids were then quantitatively analyzed by gasliquid chromatography as their trimethylsilyl derivatives. The essential amino acids were then determined. Shrimp were injected with ¹⁴C-labeled glucose and analyses performed to determine which amino acids then exhibited radioactivity, i.e., were synthesized from the labeled glucose. Those amino acids which were not manufactured from the glucose were categorized as essential.     

Feeding ecology of sympatric European shags Phalacrocorax aristotelis and great cormorants P. carbo in Iceland

The feeding ecology of the European shag (Phalacrocorax aristotelis) and the great cormorant (P. carbo) in Iceland was studied. These bird species may affect their marine environment, for instance, by predating on several commercially important fish species in coastal waters. The shag and cormorant diets were studied throughout the year in the period 1996–2000 by analysing the content of about 300 stomachs from each species. The shag relies heavily on sandeel (Ammodytes marinus) in the breeding season, whereas bull-rout (Myoxocephalus scorpius) and gadoids (Gadidae) become increasingly important in autumn and winter. The main food of the cormorant in all areas and seasons is the bull-rout. Depending on location and season, secondary food consists mainly of butterfish (Pholis gunnellus), gadoids and flatfishes (Pleuronectiformes). Similarity in diets of these two co-existing bird species was least in the breeding season when overlap in the birds’ distribution was greatest. The results suggest that predation by shags and cormorants could sometimes affect the stocks of the commercially important saithe (Pollachius virens) and plaice (Pleuronectes platessa) in Iceland.     

Landesweite immissionsbezogene Flechtenkartierung in Bayern

In 1996 within a country-wide research project, the epiphytic lichen vegetation throughout Bavaria was mapped according to Guideline VDI 3799, Part I (1995). The data providing information about air quality was collected in 190 sites. Most of the sites demonstrated little to moderate pollution, while both very high and very low levels of air pollution could be found locally. The methods outlined in Guideline VDI 3799 were slightly modified and adapted to the situation in Bavaria. Comparison of the lichen vegetation on different species of trees showed that a rigid classification of tree species as proposed in the guideline is not necessary in Bavaria. The use of several species of trees per site has proven to be favourable. The influence of the natural heterogeneity of the air-quality index in the investigated area was examined. Here, the geology turned out not to be a crucial factor. With respect to climate, it is especially the alpine region with its high levels of precipitation that stands out against the other parts of Bavaria. The results from that area may not be freely compared to those from the remaining sites. It could be shown that the Guideline VDI 3799 is applicable for large-area lichen mapping in Bavaria.     

Die Photosynthehemmung pflanzlicher Protoplasten

The ecotoxicological effect of rain water on the light-dependent, photosynthetical oxygen production of suspended protoplasts from the bean speciesVicia faba L. was used for the characterization of airborne immissions. The protoplast-biotest — with rain water samples taken in an agricultural area from March to July — showed a clear inhibition of the photosynthetical oxygen production. Simultaneously, chemical analyses on some herbicides were carried out. The concentrations determined, however, did not sufficiently explain the measured inhibition of oxygen production; so, the toxicity yielded was assumed to result from not-analyzed compounds as well as synergistic and additive effects of the rain water constituents.     

III. Ökotoxikologische Charakterisierung der Schwermetall-Immissionsmuster

The spatial variation of the immission patterns of Cr, Fe, Pb and V in the region Leipzig-Halle is dicussed in terms of similarities as well as dissimilarities. The representation by isopleths enables the identification of areas with high and low air pollution. The immission patterns can be used as criteria to select areas suitable for in-field testing so that possible effects on fauna und flora and xenobiotic fluxes can be studied at representative sites. The comparison with literature data yields a first characterization of the ecotoxic potential of the heavy-metal immission for the region. By the principal component analysis a comparative evaluation of the spatial structure of all element contents is performed, which leads to conclusions about emission sources and the physicochemical behaviour of the elements.     

Housing values,census estimates,disequilibrium, and the environmental cost of airport noise: A case study of Atlanta

Two unresolved issues about airport noise-property value studies are addressed. The first issue concerns the comparability of empirical results from aggregate census data vs individual sales values, and the second issue concerns the homogeneity and stability of results from housing price studies over time and across markets. Hedonic price models from two sets of data for a residential area near the Atlanta International Airport are estimated at two points in time 1979–1980 and 1970–1972. The available data yield similar estimates of the noise discount over time, and from the prices of individual house sales vs owner-appraised census block aggregates.     

Interaction of phenanthrene and its primary metabolite (1-hydroxy-2-naphthoic acid) with estuarine sediments and humic fractions

Experiments were conducted to compare the sorption and desorption of phenanthrene and its primary degradation product, 1-hydroxy-2-naphthoic acid (HNA), in estuarine sediment, humic acid (HA) and humin. Ionic composition, ionic strength (0.4 M) and pH (7.6) were employed to mimic native estuarine pore water at the sediment-water interface. Sorption to whole sediment and organic matter (OM) fractions was significantly lower for HNA than for phenanthrene. Whereas HNA did not sorb to HA, uptake to sediment and humin was observed, suggesting that HNA does not bind directly to OM. Phenanthrene uptake was characterized by hysteretic behavior and exhibited slow desorption. In contrast, HNA initially was more readily desorbed from sediment and humic fractions, but a significant fraction was not recovered in repeated desorption runs. The lower sorption of HNA reflects its greater polarity and water solubility, but the consistent retention of a non-desorbing fraction suggests strong binding and/or chemical transformation reactions may be important. It was postulated that abiotic transformation of HNA may occur in estuarine sediments, in part due to the presence of redox active minerals (Fe(III) and Mn(IV) oxides). The presence of Fe and Mn solids in the estuarine sediment was verified by sequential extraction and studies were then conducted to investigate the transformation of HNA in the presence of synthetic goethite (alpha-FeOOH) and birnessite (delta-MnO2) as model solids. Reaction with birnessite led to transformation of all HNA in solution within 24 h and resulted in the formation of partial oxidation products (POPs). Following reaction with goethite, HNA was present in solution and POPs were observed in the weakly bound fraction. This study indicates that degradation products of polycyclic aromatic hydrocarbons (PAHs) may have distinctly different sorption affinities and reactivities toward environmental surfaces than their parent compounds.     

The gas phase addition of NOx to olefins

The addition of N₂O₅ to 1-hexene in synthetic air results in 1,2-hexanedioldinitrate and 2-hexanon-1-ol-nitrate as the main products and some -hydroxy-1-ol-nitrate. In the reaction with cyclohexene, cis/trans-1,2-cyclohexanediol-dinitrate and cyclohexene-1-on-2-ol-nitrate have been detected. The addition of NO₃ to isoprene produces 4-nitrato-3-methylbutenal-2. The reaction of NO₃ with methylenecyclohexane and sabinene in air results in 1-(methylnitrate) cyclohexane-1-ol and both epimers of 1-(methylnitrate)-4-(isopropyl) cyclo-hexene-4-ol, respectively. The main products of the addition of NO₃ to - and β-pinene were probably rearranged compounds of the limonene type: -pinene produces 1-(methyl)-2-(nitrato)-4-(2-propane-2-ol)-cyclohex-1-ene and β-pinene produces 1-(methylnitrate)-4-(2-propane-2-ol)cyclohex-1-ene. Other rearrangements give rise to a variety of nitrates and ketonitrates of structures as yet unknown in the - and β-pinene systems.

The probably particle-borne addition of NO₂ to -pinene, β-pinene and camphene in air produces 2-nitrolimonene, 7-nitrolimonene and nitrocamphene as the main reaction products.     

Primary photoproducts and half-lives

The photolytically induced decomposition of fluoroquinolone carboxylic acids (enrofloxacin, danofloxacin, ciprofloxacin and norfloxacin) at concentrations of 10 mg/l in pure water and an irradiation intensity of 200 W/m² (xenon lamp) led to half-lives from 20.6 min (danofloxacin) to 105.9 min (norfloxacin). The environmental half-life of enrofloxacin was calculated by the GCSOLAR program and resulted in 1.8 to 55.4 hours, depending on the season and degree of latitude. During the irradiation procedure, products were built up which primarily demonstrated alterations involving the piperazine ring as compared with the parent compounds. The amount of¹⁴CO₂ evolved by the photomineralization of¹⁴C-labeled enrofloxacin reached 26.4 % of the applied radioactivity. The main photoproducts were isolated by HPLC and their structural elucidation was carried out by different spectroscopic methods (MS, GC/MS and¹H-NMR).