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  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Oecologia 113 (1998), S. 415-427 
    ISSN: 1432-1939
    Schlagwort(e): Key words Cattle pastures ; Deforestation ; Nutrient cycling ; Biomass burning ; Tropical forests
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Conversion to cattle pasture is the most common fate of the ≈426,000 km2 of tropical forest that has been deforested in the Brazilian Amazon. Yet little is known about the biomass, C, nutrient pools, or their responses to the frequent fires occurring in these pastures. We sampled biomass, nutrient pools and their losses or transformation during fire in three Amazonian cattle pastures with typical, but different, land-use histories. Total aboveground biomass (TAGB) ranged from to 53 to 119 Mg ha−1. Residual wood debris from the forests that formally occupied the sites composed the majority of TAGB (47–87%). Biomass of fine fuels, principally pasture grasses, was ≈16–29 Mg ha−1. Grasses contained as much as 52% of the aboveground K pool and the grass and litter components combined composed as much as 88% of the aboveground P pool. Fires consumed 21–84% of the TAGB. Losses of C to the atmosphere ranged from 11 to 21 Mg ha−1 and N losses ranged from 205 to 261 kg ha−1. Losses of S, P, Ca, and K were 〈33 kg ha−1. There were no changes in surface soil (0–10 cm) nutrient concentration in pastures compared to adjacent primary forests. Fires occur frequently in cattle pastures (i.e., about every 2 years) and pastures are now likely the most common type of land burned in Amazonia. The first 6 years of a pastures existence would likely include the primary forest slash fire and three pasture fires. Based upon our results, the cumulative losses of N from these fires would be 1935 kg ha−1 (equivalent to 94% of the aboveground pool of primary forest). Postfire aboveground C pools in old pastures are as low as 3% of those in adjacent primary forest. The initial primary forest slash fire and the repeated fires occurring in the pastures result in the majority of aboveground C and nutrient pools being released via combustion processes rather than decomposition processes.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 1432-203X
    Schlagwort(e): Key wordsAgrobacterium-mediated transformation ; Datura meteloides ; Preculture period ; Transgene expression
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A transformation system is described for Datura meteloides using the supervirulent Agrobacterium tumefaciens strain 1065, carrying both the β-glucuronidase (gusA) and neomycin phosphotransferase II (nptII) genes between the T-DNA border sequences of the binary vector. The importance of conditions such as the preculture period of the plant tissues, wounding, bacterial dilution and incubation time were evaluated in terms of transgenic plant production. A preculture period of 2–3 days, using a 1:20 or 1:10 (vol:vol) dilution of an overnight bacterial culture, resulted in optimum shoot regeneration, with 48% from a total of 576 explants regenerating transformed shoots. Expression of the gusA and nptII genes was confirmed by a GUS fluorometric assay and by NPTII ELISA. Southern analysis revealed the integration of both transgenes, which segregated as dominant Mendelian traits in seed progeny.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Clinical rheumatology 14 (1995), S. 656-662 
    ISSN: 1434-9949
    Schlagwort(e): Aceclofenac ; Nonsteroidal-Antiinflammatory Drugs ; Diclofenac ; Osteoarthritis ; Efficacy ; Safety
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A multicentre randomised, double-blind, parallel group, general practice study was undertaken to investigate the efficacy and safety of aceclofenac (200 patients, 100mg twice daily and placebo once daily) in comparison with diclofenac (197 patients, 50mg three times daily) in patients with osteoarthritis of the knee. The treatment period of twelve weeks was preceded by a washout period of two weeks duration. At end point, patients in both aceclofenac and diclofenactreated groups exhibited significant improvement in pain intensity (p=0.0001). Although both treatment groups showed significant improvement in all investigators' clinical assessments (joint tenderness, swelling, pain on movement, functional capacity, overall assessment), there were no significant differences between the groups. There was, however, a trend towards greater improvement in complete knee movement and reduced pain on movement with aceclofenac. In patients with initial flexion deformity, aceclofenac was significantly more effective than diclofenac in improving knee flexion after 2–4 weeks of treatment. Patients' subjective assessment of pain relief demonstrated significantly greater efficacy with aceclofenac. At end point, 71% of patients in the aceclofenac group reported improvement in pain intensity as compared to 59% treated with diclofenac (p=0.005). Tolerability of aceclofenac was better than with diclofenac as fewer patients experienced gastrointestinal adverse events. In particular, the incidence of treatment related diarrhoea was less with aceclofenac (1%) than with diclofenac (6.6%). In summary, this study supports a therapeutic role for aceclofenac in arthritis and suggests that it is an alternative NSAID to diclofenac in the treatment of osteoarthritis.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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