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61.
62.
James C. Belke Deborah Y. Dietrich 《Journal of Loss Prevention in the Process Industries》2005,18(4-6):375-379
The United States' approach to incident prevention and response to hazardous chemical facilities has undergone two major transformations in the last 20 years. The first was triggered by the Bhopal tragedy in 1984, which led to major changes within the US chemical industry and a series of Federal laws and regulations intended to prevent major chemical accidents. A more recent transformation is currently underway in the wake of the 9/11 attacks on New York and Washington. It involves the advent of various security-related requirements affecting many of the same facilities covered under the existing accident prevention rules. This paper provides an overview of these transformations and their impacts. 相似文献
63.
The ormer, Haliotis tuberculata Linnaeus, 1758, is able to accumulate paralytic shellfish toxins (PST) in the foot side skin. Epidermal and secretory cells are described
separately for the pedal side and sole epithelia, as notable differences have been observed. Melanin and photosynthetic pigment
granules in the epidermal cells of the foot side epithelium give this skin its appearance and characteristic color. This epidermis
also has abundant secretory cells containing at least three kinds of secretory granules. Conversely, the epidermal cells of
foot sole epithelium do not have pigment granules, and the secretory cells are mostly subepithelial. Immunohistochemical reaction
against PST (saxitoxin and its derivatives) showed that the toxins are located in specific cells of the foot side epithelium,
which are distinct from the epidermal cells. Immunofluorescence also reveals toxins throughout many areas of the mucilage
covering the epithelium, suggesting the secretory nature of the cells containing the toxins. These results do not show any
apparent relationship between melanin or photosynthetic pigment granules and PST content. PST were not detected in the foot
sole epithelium either immunohistochemically or by HPLC. Considering the toxic characteristics of ormers described in previous
studies and the results presented here, the authors discuss the role of toxins retained or produced by the foot side epithelium
Received: 25 July 2000 / Accepted: 7 November 2000 相似文献
64.
Dietrich Hochrainer 《Die Naturwissenschaften》1965,52(15):449-449
65.
Dietrich Fengel 《Die Naturwissenschaften》1966,53(14):363-364
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Haas K Köhler U Diehl S Köhler P Dietrich S Holler S Jaensch A Niedermaier M Vilsmeier J 《Ecology》2007,88(11):2915-2925
It is notoriously difficult to study population interactions among highly mobile animals that cannot be meaningfully confined to experimental plots of limited size. For example, migratory water birds are believed to suffer from competition with resident fish populations for shared food resources. While observational evidence in support of this hypothesis is accumulating, replicated experiments addressing this issue at the proper spatial scale are lacking. Here, we report from a replicated whole-system experiment in which we stocked large (0.07 km2), shallow (< or =2.5 m deep), highly eutrophic ponds in the bird protection area "Ismaninger Speichersee mit Fischteichen" with different densities of carp and assessed the responses of water birds and their food resources during summer over several years. In all years, the biomasses of benthic macroinvertebrates, macroalgae, and macrophytes as well as the densities of herbivorous, carnivorous, and omnivorous water birds were reduced in carp ponds compared to fishless ponds. The negative effects of carp on food resources and on the numbers of water birds feeding in carp ponds increased over the season (May-September) and were stronger at high than at low stocking densities of carp. Consequently, differences in resource densities between ponds with and without carp increased, and the ranking of ponds with respect to resource densities became more predictable over the season. These factors may have contributed to a seasonal improvement of the birds' abilities to track resource densities across ponds, as suggested by tight correlations of bird numbers on ponds with resource densities late, but not early, in the season. 相似文献
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