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411.
Bird use of conservation tillage-established (CT—seedbed preparation without soil inversion) crops was assessed at two adjacent sites in western Hungary, in comparison with conventionally established (mouldboard ploughed—P) fields. Bird abundance was assessed in a typical rotation of spring-sown maize and winter wheat in three consecutive winters. In the first winter, several species and the guild of seed-eating passerines were significantly more abundant on CT established plots, in both crop types. In the second winter, only starlings were more abundant on CT plots. In the third winter, only skylarks favoured CT over P plots. In combination with agri-environment scheme measures designed to provide resources for biodiversity, conservation tillage could play a role in softening the impact of agriculture on farmland birds in Hungary and elsewhere in Eastern Europe, in addition to its potential for reducing soil erosion and diffuse pollution.  相似文献   
412.
In this study, an inventory of air pollutant emission estimates from major air polluting sources in Turkey for period between 1985 and 2005 with 5-year intervals were estimated. Inventory covers anthropogenic sources of five major air pollutants of particulate matter, sulfur dioxide, carbon monoxide, nitrogen oxides and non-methane volatile organic compounds. Their break-down with respect to main activity sectors were shown and their distribution by the largest industrial source categories were worked out as annual estimates. This inventory and its analysis point to serious environmental implications of air pollutants and a need to develop a policy plan for reducing these emissions.  相似文献   
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2+   concentrations tropomyosin is located at the edge of the thin filament, thereby interfering with the formation of strong actin-myosin linkages (blocked state). An increase in Ca2+ activity causes an azimuthal shift of tropomyosin around the filament (by about 30°), thereby increasing the probability of low-force crossbridge interaction, a process which by cooperative effects induces further tropomyosin movement (by an additional 10°) which results in the open state of the filament characterized by forceful crossbridge interaction. (This mechanism may be analogous to that in ligand-gated ion channels, where ligand binding increases the open probability of the pore.) The extent of activation then depends on the free Ca2+ concentration and on the calcium sensitivity of the thin filament that may be affected by protein phosphorylation, crossbridge attachment, the troponin isoform composition of the filament, and novel calcium-sensitizing drugs that act on the contractile or regulatory proteins and thus increase the force of the heart.  相似文献   
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Foreword     
Mitigation and Adaptation Strategies for Global Change -  相似文献   
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 In several branches of science and technology a gaseous phase is dispersed into a liquid in the form of bubbles, a gaseous component then dissolves into the liquid and subsequently undergoes chemical reaction. The overall process performance can be improved substantially when the area of gas–liquid contact is increased. By subjecting the liquid phase to low frequency vibrations, the bubbles are shown to suffer significant breakage, induced by resonance. When the vibration is properly tuned, the interfacial area is found to increase by a factor of 1.8–2.4, depending on the properties of the liquid. Resonance-induced bubble breakage phenomena have a great potential for improving the rates of chemical processes involving fast reactions, with minimal energy input. Received: 7 July 2000 / Accepted in revised form: 28 August 2000  相似文献   
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This paper investigates the current treatment of environmental issues by two companies within the large made-to-order sector. Fifty questionnaires were issued to the design team of each company to assess current practice in the integration of environmental issues with design activities, awareness of environmental issues, awareness of existing environmental design tools and the preferred format for a potential clean design tool.  相似文献   
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