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Poerschmann J Gathmann A Augustin J Langer U Górecki T 《Journal of environmental quality》2005,34(5):1508-1518
Transformation of crops, including maize (Zea mays L.), with the cry1Ab gene from Bacillus thuringiensis to combat lepidopteran pests results in pleiotropic effects regarding lignin biosynthesis. Lignin patterns in stems and leaves of two genetically modified Bt-maize varieties (Novelis T and Valmont T) were studied along with their non-Bt near-isolines (Nobilis and Prelude, respectively). Molecular-level based thermochemolysis using tetramethylammonium hydroxide (TMAH) in combination with gas chromatography-mass spectrometry (GC-MS) was used to quantitate the total lignin contents and to identify monomeric lignin subunits including p-hydroxyphenyl (P), guaiacyl (G), and syringyl (S) moieties. The results were supplemented and confirmed by cupric oxide oxidation. The stems of the transgenic lines had higher concentrations of total lignin than the respective isogenic lines: Valmont T/Prelude by 18% and Novelis T/Nobilis by 28%. In contrast, differences in the total lignin concentration of leaves between the transgenic and the respective near-isogenic lines were marginal. There were significant modifications in the ratio of p-hydroxyphenyl/guaiacyl/syringyl molecular marker units of stem lignin between transgenic and isogenic lines. The guaiacyl units (in particular the G18 marker) accounted chiefly for the higher total lignin contents in the transgenic lines. The leaf lignin patterns did not show significant differences in molecular markers between isogenic and transgenic lines. TMAH-induced thermochemolysis--conducted in both the on-line and off-line modes--provided detailed information on the molecular composition of lignin, thus proving superior to the established "wet chemistry" methods of lignin determination. 相似文献
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Juergen B. Donges 《Resources Policy》1979,5(1):2-15
This paper discusses some major economic problems raised by proposals towards a new international commodity policy. The author analyses the economic implications of commodity price stabilization and price raising, and focuses on the questions of operationality of the IPC and on the alleged merits of a common financing of individual buffer stocks. He discusses financing schemes compensating for fluctuations of export earnings, and finally points to a number of areas in which Europe could make a constructive contribution to mitigate the commodity problem. 相似文献
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Paulussen Juergen 《中国人口.资源与环境(英文版)》2005,3(1)
CHALLENGE OF URBANIZATION IN CHINAAccording to the forecast, the proportion of urbanpopulation in China will increase from about 35% todayto more than 50% in the next two decades. Due to thisprocess, huge areas of former agricultural and natural landare currently turned into build-up-areas and traffic-ways.Approximately 40-50% of this area will be developed forindustrial use. Further more, large sites occupied by oldindustry ("brownfields") will be redeveloped. Thisdevelopment of … 相似文献
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Juergen Vehlow Britta Bergfeldt Rian Visser Carl Wilén 《Journal of Material Cycles and Waste Management》2007,9(2):130-139
In the European Union (EU), waste management is almost totally regulated by EU directives, which supply a framework for national
regulations. The main target in view of sustainability is the prevention of direct disposal of reactive waste in landfills.
The tools to comply with these principles are recycling and material recovery as well as waste incineration with energy recovery
for final inertization. The adaptation of the principles laid down in EU directives is an ongoing process. A number of countries
have already enacted respective national regulations and their realization shows that recycling and incineration are not in
competition but are both essential parts of integrated waste management systems. In the EU, the amount of residual waste available
for energy recovery can supply approximately 1% of the primary energy demand. About 50% of the energy inventory of municipal
solid waste (MSW) in most EU countries is of biogenic origin, and MSW is to the same extent to be looked upon as regenerative
fuel. Hence part of the CO2 released from waste incineration is climate neutral. In the EU, this share could produce savings of the order of 1% of annual
CO2 emissions if energy from MSW replaced that derived from fossil fuel. 相似文献
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Small farm ponds: overlooked features with important impacts on watershed sediment transport
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Matthew D. Berg Sorin C. Popescu Bradford P. Wilcox Jay P. Angerer Edward C. Rhodes Jason McAlister William E. Fox 《Journal of the American Water Resources Association》2016,52(1):67-76
Despite their size, small farm ponds are important features in many landscapes. Yet hydrographical databases often fail to capture these ponds, and their impacts on watershed processes remain unclear. For a 230‐km2 portion of central Texas, United States (U.S.), we created a historical inventory of ponds and quantified the accuracy of automated detection methods under varying drought conditions. In addition, we documented pond dredging/enlargement events and identified sites that had been abandoned. We also analyzed sediment cores from downstream reservoirs to track changes in watershed sediment transport. Over 75 years, pond densities increased more than 350% — to among the highest documented in the U.S. — and the ability of automated methods to detect these ponds was highly dependent on drought severity (R2 = 0.96). Approximately 5% of ponds present in the 1950s were no longer present in 2012, while 33% were dredged between 1937 and 2012. Downstream reservoir sedimentation has decreased by an average of 55% as ponds have increased in number. These findings suggest that small ponds and the maintenance of trapping efficiency have large‐scale impacts on sediment dynamics. Accurately accounting for these storage effects is vital to water resource planning efforts. 相似文献
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Schlumpf M Kypke K Wittassek M Angerer J Mascher H Mascher D Vökt C Birchler M Lichtensteiger W 《Chemosphere》2010,81(10):1171-1183
In order to assess potential risks of exposure to environmental chemicals, more information on concomitant exposure to different chemicals is needed. We present data on chemicals in human milk of a cohort study (2004, 2005, 2006) of 54 mother/child pairs, where for the first time, cosmetic UV filters, synthetic musks, parabens and phthalate metabolites were analyzed in the same sample along with persistent organochlor pollutants (POPs), i.e., organochlor pesticides and metabolites, polybrominated diphenylethers and polychlorinated biphenyls (PCBs). The two groups of chemicals exhibited different exposure patterns. Six out of seven PCB congeners and a majority of pesticides were present in all milk samples, with significant correlations between certain PCB congener and pesticide levels, whereas the cosmetic-derived compounds, UV filters, parabens and synthetic musks, exhibited a more variable exposure pattern with inter-individual differences. UV filters were present in 85.2% of milk samples, in the range of PCB levels. Comparison with a questionnaire revealed a significant correlation between use of products containing UV filters and their presence in milk for two frequently used and detected UV filters, 4-methylbenzylidene camphor and octocrylene, and for the whole group of UV filters. Concentrations of PCBs and organochlor pesticides were within ranges seen in Western and Southern European countries. For several POPs, mean and/or maximum daily intake calculated from individual concentrations was above recent US EPA reference dose values. Our data emphasize the need for analyses of complex mixtures to obtain more information on inter-individual and temporal variability of human exposure to different types of chemicals. 相似文献
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Gobiid fishes of the genus Gobiodon live in strong association with certain reef-building corals that vary considerably in size and architecture. These fishes hence are excellent model systems for studying evolutionary adaption to specific microhabitats. Using a sample of Gobiodon histrio and G. rivulatus and their most important host corals (Acropora digitifera and A. gemmifera) from the northern Red Sea, we assess (1) how corals that are occupied by gobies differ in their architecture from colonies that are not occupied and (2) how fish body shape is associated with the architecture of their host coral. Fish body shape was assessed by geometric morphometric techniques. Coral measurements included colony size, branch length (BL), and interbranch as well as branch tip distance of adjacent branches, for which we applied a new and non-destructive measurement technique based on casts of two-component epoxy resin. The most important factor influencing the occupation of corals was a BL of more than 5 cm. The distance between coral branches was clearly related to the width of the fishes and hence constrained overall fish size. G. histrio and G. rivulatus differ in adult body shape as well in their allometric development of lateral body compression, resulting in different maximum body sizes attainable in the restricted interbranch space of corals. The strong dependence of coral-associated fishes on large coral colonies with specific architectures increases the extinction risk of fishes within deteriorating coral reefs. 相似文献