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1.
After application of [14C]lindane to the nutrient medium (1.45 ppm), 14.1% of the radioactivity was taken up by 12 lettuce plants during 4 weeks; in the nutrient medium, 7.8% was recovered after the same time interval. The radioactivity in the nutrient extract comprised: unchanged lindane (about 82%); free 2,3,4,6-tetrachlorophenol, free pentachlorophenol, conjugates of pentachlorophenol, and an unidentified polar compound (a total of 15%); 1,2,3-trichlorobenzene, 1,2,3,4-tetrachlorobenzene, pentachlorobenzene, hexachlorobenzene, 2,3,4,5,6-pentachlorocyclohex-1-ene, and probably 1,2,3,4,5,6-hexachlorocyclohexene (a total of 3%). The radioactivity extracted from plants consisted of unchanged lindane (about 77%); free 2,3,4,6-tetrachlorophenol, conjugates of a tetrachlorophenol and pentachlorophenol, and a strongly hydrophilic compound that was not identified (a total of 20%); 1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene, pentachlorobenzene, 2,3,4,5,6-pentachlorocyclohex-1-ene, and probably 1,2,3,4,5,6-hexachlorocyclohexene (a total of 3%). Identification was carried out by means of comparisons of chromatographic properties and of the mass spectra with those of authentic reference compounds. The significance of hexachlorobenzene as a metabolite of lindane is discussed.  相似文献   
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TREATMENT OF DIAPHRAGMATIC HERNIA IN BUFFALOES   总被引:2,自引:0,他引:2  
The surgical treatment of diaphragmatic hernia attempted on 19 lactating buffaloes is described. Thirteen cases recovered uneventfully, 1 recovered after developing brisket oedema and 5 died, 3 during surgery and 2 postoperatively. The desired depth of anaesthesia was achieved by the administration of 6% chloral hydrate followed by 5% thiopentone sodium. A postxiphoid approach and the use of a continuous lock stitch suture were preferred to repair the vent in the diaphragm. Pre- and post-operative use of hydrocortisones and fluids and sufficient tissue oxygenation by controlled positive pressure respiration are believed to be keys to the success of the treatment adopted.  相似文献   
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A study conducted to assess the floor vegetation shows the presence of 17 species underPopulus deltoides in comparison to 28, 29 and 35 underAlbizia lebbeck, Dalbergia sissoo and mix-culture plantations, respectively. Further, the biomass and density of floor vegetation is considerably reduced underP. deltoides compared to other plantations. In addition, the indices for species richness, evenness, dominance and diversity are also reduced underP. deltoides showing some inhibitory mechanism being operative under these plantations. Based on available literature, allelopathy is speculated to be responsible for this reduction.  相似文献   
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Field and laboratory experiments were carried out to describe the effects of Aporrectodea nocturna on soil characteristics in a pre-alpine meadow and to support the development of a model of cast production. In the prealpine meadow, increased cast production, first observed about 20 years ago around a newly planted hedge, was recorded to a distance of maximal 170 m from the hedge. Numbers of A. nocturna between 130 and 165 m from the hedge decreased from 164 to 16 individuals m-2. In the same area cast production steadily decreased from about 1.5 kg m-2 week-1 to nil, the plant community structure changed and the microbial biomass decreased, but the root biomass and the moisture content did not change. Laboratory experiments demonstrated that high cast production was not a specific feature of the A. nocturna population nor of the soil in the meadow. Diapause of A. nocturna was terminated in the laboratory during September. A model of cast production potential by the earthworm A. nocturna was established using laboratory determinations of the relationships with body weight, temperature, and water potential. The model was shown to predict cast production in the field given the assumption that the water potential was 0 MPa. According to the model, 81% of surface cast production was by juveniles, and 19% by adults of A. nocturna.  相似文献   
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Rice, with its wide geographic distribution extending from 50°N to 35°S, is expected to be the most vulnerable cultivated crop to future changing climates. Among the different abiotic stresses, extreme temperatures coinciding with critical developmental stages, increasingly frequent floods and drought spells, and worsening sea water inundation are some of the major threats to sustainable rice productivity. Following the successful implementation of molecular marker‐assisted backcrossing to introgress large‐effect QTL for submergence tolerance in rice mega varieties, rice breeding for drought, salinity and, recently, heat tolerance is employing the same approach. Although tolerance for combined submergence and salinity has been achieved, developing rice varieties with multiple tolerance for other abiotic and biotic stresses and finding the appropriate agronomic package to exploit their performance remain a challenge. The major bottleneck is the lack of unidentified large‐effect QTL for other abiotic stresses that are strongly influenced by genotype × environment (G × E) interaction. Rapid advances in the use of molecular tools, including a plethora of SNP markers, are expected to facilitate the development of major abiotic stress‐tolerant rice. In response to the actual farmer field situation, progress achieved in understanding and developing independent abiotic stress tolerance is being exploited to combine tolerances (for example, heat and drought; salinity and submergence) to address emerging environmental problems across a wide range of rice ecosystems.  相似文献   
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The economic yield of chickpea, lentil, wheat, cauliflower, barseem, and toria in a 12-m-wide strip to the south of 8 ± 1-year-old Eucalyptus tereticornis shelterbelts (three different locations) was reduced by more than half. Among all the crops under study, the yield of chickpea was reduced by the maximum extent. The content of soil phytotoxins was maximum in the litter-free top soil surface, compared to that at 30 or 60 cm depths, at all distances from the Eucalyptus. Maximum content of phytotoxins was found at 1 m from the tree line for all depths. These soil phytotoxins impaired the germination of Lens esculentum, thus indicating an allelopathic effect. It is included that the poor perfornce of crops in the sheltered area is related to an allelopathic effect of the Eucalyptus.  相似文献   
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A study was conducted to determine the potential and nature of root‐mediated allelopathic interference of Chenopodium murale on wheat. Early growth of wheat reduced significantly in agar medium where C. murale seedlings were previously growing as well as in rhizosphere soil of C. murale. The reduction in wheat growth was due to the presence of inhibitory metabolites released by roots of C. murale in the growth media. Even the soil incorporation of root residues also reduced the wheat growth in terms of seedling length and seedling dry weight. Only a partial amelioration in growth inhibition occurred upon charcoal supplementation or nitrogen fertilization in these amended soils. Root residues did not reduce the available nutrients in the soil, which was rather nutrient rich. These results indicated the definite role of allelopathy of C. murale roots in retarding wheat growth. Root amended soils contained significantly higher amount of phytotoxic phenolics as the putative allelochemicals, which were ferulic acid, vanillic acid, p‐coumaric acid and benzoic acid. The study concluded that C. murale roots and their exudates exerted allelopathic effects on wheat by releasing water‐soluble phenolic acids as putative allelochemicals in soil.  相似文献   
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