Riding arenas and different riding track surfaces in relation to the airway contamination in horses. Laboratory studies on riding surfaces]

29 samples of commonly used surfaces were tested for their water characteristics (litre weight, water capacity, water binding, water evaporation) and their contribution to airborne fungal spores (dust formation, dust setting). The results are discussed in comparison to the literature with regard to the environment. The results are: 1. Any surface--no matter of what material--eventually causes air pollution with fungal spores and dust. 2. Correct watering prevents air pollution by any surface. 3. Artificial products have no advantage over natural materials in the parameters tested. 4. The question of proper disposal of old surface material has to be clarified before purchase. The results show that a mixture of sand and wood shavings should be recommended as a surface for indoor arenas, especially in regard to environmental protection and proper disposal.     

The effects of low voltage current on healing of thermal third degree wounds.

Bilateral third degree burns were created on the flanks of eight miniature swine. Each animal had one side treated daily with low intensity direct (LIDC) of 400 microamperes (muA) by contact electrode for 2 hours morning and afternoon until healing occurred. The polarity of the electrode was negative in 4 pigs and positive in 4 pigs. One group of 4 pigs had the eschar surgically removed 24 hours post burn. Weekly biopsies and cultures were taken of treated and control wounds. Results indicated: local treatment of 400 muA LIDC did not hasten or delay healing of thermal third degree burns; escharectomy hastened wound healing by 10 days, and superficial proteus infection occurred in 80% of all wounds.     

A new plant-based bioassay for aquatic sediments

Background, Goal and Scope  To date, standardised bioassays for the assessment of the ecotoxicological potential in sediments and dredged material use test organisms like bacteria, algae and crustaceae. This paper presents the development and application of a novel sediment contact test (whole sediment) withMyriophyllum aquaticum, a representative of rooted aquatic macrophytes. The aim of the present study is to demonstrate the value of a sediment contact test with rooted macrophytes as a supplement to existing test batteries in order to improve the assessment of sediment toxicity. Methods  The newly developed sediment contact test withMyriophylhim aquaticum was applied to natural whole sediments. For performing the test, whorls ofMyriophyllum aquaticum were directly planted in the native sediment and incubated in the light at 24°C (cf. section results and discussion). The end points of the test were the number of the shoots and the fresh weight of the whole plants. The duckweed growth inhibition test withLemna minor according to ISO/DIS 20079 was performed in pore waters from sediment samples. The results of the sediment contact test withMyriophyllum aquaticum were compared with each other and with those of the aquatic duckweed test. Results and Discussion  A test protocol for the new plant-based sediment contact test using the aquatic plantMyriophyllum aquaticum as an indicator was developed. The best control sediment proved to be the OECD sediment (OECD 207). A test period of 10 days appeared to be sufficient for the test. The increase of biomass and the derived growth rate were found to be the most suitable evaluation parameters. The growth behaviour ofMyriophyllum aquaticum differed depending on the origin of sediments. Therefore, plant-affecting contamination, that is bound in sediments, was indicated. Conclusions  The novel sediment contact test withMyriophyllum aquaticum can indicate phytotoxic effects in sediments. Therefore, it allows a better assessment of the overall-toxicity in whole sediments. Recommendations and Outlook  The sediment contact test withMyriophyllum aquaticum is a valuable tool for the evaluation of the ecotoxicological risk potential of waters and sediments. It should become a complement to a standardised test battery generally used for the assessment of sediment toxicity.     

Modern forestry vehicles and their impacts on soil physical properties

“Close-to-nature forest stands” are one central key in the project “Future oriented Forest Management” financially supported by the German Ministry for Science and Research (BMBF). The determination of ecological as well as economical consequences of mechanized harvesting procedures during the transformation from pure spruce stands to close-to-nature mixed forest stands is one part of the “Southern Black Forest research cooperation”. Mechanical operations of several typical forest harvesting vehicles were analysed to examine the actual soil stresses and displacements in soil profiles and to reveal the changes in soil physical properties of the forest soils. Soil compaction stresses were determined by Stress State Transducer (SST) and displacement transducer system (DTS) at two depths: 20 and 40 cm. Complete harvesting and trunk logging processes accomplished during brief 9-min operations were observed at time resolutions of 20 readings per second. Maximum vertical stresses for all experiments always exceeded 200 kPa and at soil depths of 20 cm for some vehicles and sequences of harvesting operations approached ≥500 kPa. To evaluate the impacts of soil stresses on soil structure, internal soil strengths were determined by measuring precompression stresses. Precompression stress values of forest soils at the field sites ranged from 20 to 50 kPa at soil depths of 20 cm depth and from 25 to 60 kPa at soil depths of 40 cm, at a pore water pressure of −60 hPa. Data obtained for these measured soil stresses and their natural bearing capacities proved that sustainable wheeling is impossible, irrespective of the vehicle type and the working process. Re-occurring top and subsoil compaction, increases in precompression stress values in the various soil horizons, deep rut depths, vertical and horizontal soil displacements associated with shearing stresses, all affected the mechanical strengths of forest soils. In order to sustain naturally “unwheeled” soil areas with minimal compaction, it is recommended that smaller machines, having less mass, be used to complete forest harvesting in order to prevent or at least to maintain currently minimal-compacted forest soils. Additionally, if larger machines are required, permanent wheel and skid tracks must be established with the goal of their maximum usefulness for future forest operations. A first step towards accomplishing these permanent pathways requires comprehensive planning with the Federal State Baden-Württemberg. The new guideline for final opening with skid tracks (Landesforstverwaltung Baden-Württemberg, 2003) proposes a permanent skid track system with a width of 20–40 m.     

Three-dimensional structure of favin: saccharide binding-cyclic permutation in leguminous lectins

The three-dimensional structure of favin, the glucose- and mannose-binding lectin of Vicia faba (vetch, broad bean), has been determined at a resolution of 2.8 angstroms by molecular replacement. The crystals contain specifically bound glucose and provide the first high-resolution view of specific saccharide binding in a leguminous lectin. The structure is similar to those of concanavalin A (Con A) and green pea lectin; differences from Con A show that minimal changes are needed to accommodate the cyclic permutation in amino acid sequence between the two molecules. The molecule is an ellipsoidal dimer dominated by extensive beta structures. Each protomer contains binding sites for two divalent metal ions (Mn2+ and Ca2+) and a specific saccharide. Glucose is bound by favin in a cleft in the molecular surface and has noncovalent contacts primarily with two peptide loops, one of which contains several metal ion ligands. The specific carbohydrate-binding site is similar to that of Con A in location and general peptide folding, despite several differences in specific amino acid residues.     

The composite genome of the legume symbiont Sinorhizobium meliloti

The scarcity of usable nitrogen frequently limits plant growth. A tight metabolic association with rhizobial bacteria allows legumes to obtain nitrogen compounds by bacterial reduction of dinitrogen (N2) to ammonium (NH4+). We present here the annotated DNA sequence of the alpha-proteobacterium Sinorhizobium meliloti, the symbiont of alfalfa. The tripartite 6.7-megabase (Mb) genome comprises a 3.65-Mb chromosome, and 1.35-Mb pSymA and 1.68-Mb pSymB megaplasmids. Genome sequence analysis indicates that all three elements contribute, in varying degrees, to symbiosis and reveals how this genome may have emerged during evolution. The genome sequence will be useful in understanding the dynamics of interkingdom associations and of life in soil environments.     

Semisynthesis and pharmacological investigation of lipo-alkaloids prepared from aconitine

Processed aconite drugs are widely used in Eastern medicine as painkillers and antirheumatic agents. It is known that the traditional processing of aconite drugs increases the amount of lipo-alkaloids. In order to obtain information about the pharmacological potential of these compounds, semisynthesis of 9 aconitine-derived lipo-alkaloids was carried out and their COX-1, COX-2 and LTB₄ formation inhibitory activities were investigated. It was found that compounds esterified with unsaturated fatty acids demonstrated significant COX-2 inhibitory effects, while in the COX-1 assay only 14-benzoylaconine-8-O-eicosapentaenoate exerted remarkable activity. The inhibition of LTB₄ formation was pronounced in cases of long chain fatty acid derivatives.     

Die Wirksamkeit von Isomeren des Hexachlorcyclohexans gegen holzzerstörende Käferlarven

Zusammenfassung Es wurde die Giftwirknng der α-, β-, γ- und δ-Isomeren des Hexachlorcyclohexans gegenüber Eilarven des Hausbockk?fers (Hylotrupes bajulus L.) und mittelgro?en Larven des Gew?hnlichen Nagek?fers (Anobium punctatum De Geer) bestimmt. Gegenüber beiden Larvenarten erwies sich das λ-Isomere erwartnngsgema? als der bei weitem wirksamste Stoff. Danach folgt, je nach den Versuchsbedingungen um den Faktor 10 bis 20100 schlechter, unerwartet das α-Isomere. Das δ- und noch ausgepr?gter das β-Isomere sind bedeutend weniger wirksam. Der Unterschied gegenüber dem γ-Isomeren liegt für Hausbock-Eilarven in der Gro?enordnung von 1500 und 80000; für Anobien-Larven ist er mit < 500 geringer. Das Ergebnis mit dem α-Isomeren ist beachtenswert.

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Summary The toxicity of the α-, β-, γ-, and δ-isomers of hexachlorocyclohexane towards egg-larvae of the Old House Borer (Hylotrupes bajulus L.) and medium-sized larvae of the Common Furniture Beetle (Anobium punctatum De Geer) was determined. As was to be expected, the γ-,isomer proved by far most effective against both species of larvae. Then, unexpectedly, the α-isomer follows, inferior by the factor 10 to 2000 according to the testing conditions. The δ- and, even more distinctly, the β-isomer show a considerably smaller efficiency. The difference to the γ-isomer amounts to a relation of 1500 and 80000 withHylotrupes egg-larvae; it is smaller (<500) withAnobium larvae. The result obtained with the α-isomer is remarkable.

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Résumé L'effet toxique des α-, β-, γ-, et δ-isomères du chlorocyclo-hexane contre des ovule-larves desHylotrupes bajulus L. et contre des larves de moyenne grandeur del'Anobium punctatum De Geer fut déterminé. Comme supposé, le γ-isomère était bien la plus efficace substance. Inattendu, le α-isomère, suit, selon les conditions d'essai plus mauvaises du facteur 10 à 2000. Le δ-isomè re et plus distinctement le β-isomère sont efficaces beaucoup moins. La différence entre ces derniers et les γ-isomères est de 1500 et 80000 pour des larves deHylotrupes bajulus L.; elle e'st moindre (< 500) pour des larves del'Anobium punctatum De Geer.

     

Mitigating nitrous oxide emissions from agricultural soils by precision management

Nitrous oxide (N₂O) emissions make up a significant part of agricultural greenhouse gas emissions. There is an urgent need to identify new approaches to the mitigation of these emissions with emerging technology. In this short review four approaches to precision managements of agricultural systems are described based on examples of work being undertaken in the UK and New Zealand. They offer the opportunity for N₂O mitigation without any reduction in productivity. These approaches depend upon new sensor technology, modeling and spatial information with which to make management decisions and interventions that can both improve agricultural productivity and environmental protection.