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The Lizard Peninsula is an isolated area of unique and sensitive ecology and the occurrence of damaging ozone concentrations over the peninsula in spring challenges the successful sustainable management of the area. Ozone concentrations over Goonhilly Downs on the Lizard Peninsula in Cornwall were measured in spring 2002 using continuous monitoring and spatial mapping (diffusion tubes). Data obtained using a continuous ozone monitor (1/03/02 to 31/03/02) showed that the AOT40 5-day values were in a range from 2 to 800 μg m-3 hr (AOT40 is the sum of the differences between the measured hourly ozone concentration (μg m-3) and 80 μg m-3 (when the concentration exceeds 80 μg m-3) for the hours when global radiation exceeds 50 Wm-2). Contour mapping of ozone concentrations measured with diffusion tubes suggested that over a 2 km2 sampling area significant microscale variations were occurring with ozone concentrations ranging between 48–129 μg m-3 for one two-week period and 62–210 μg m-3 for the other.Unusually high diurnal variations in ozone concentrations were also observed at Goonhilly. It is thought that temperature inversions caused the entrapment of ozone at the surface level. 相似文献
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An association with a rank correlation of 0.55 (p = 0.06) was obtained between monthly rainfall and monthly abortions for a group of 24 farms in tropical Australia where cows grazed predominantly summer rain-dependent pasture. A similar association was found among cows grazing nitrogen-fertilised, irrigated pasture in winter in the same area. On farms with irrigated pasture the first service conception and abortion rates in herds which grazed intensively during the night (abortion 8.9%; first service conception 42.9%) differed significantly from those which grazed during the day (abortion 6.4%; first service conception 52.9%), and this suggested that increased abortion rates and decreased first conception rates may be part of the one syndrome. An hypothesis was developed that the feeding of immature nitrogen-fertilised pasture, rich in protein and stimulated by rain or irrigation, is associated with an increased abortion rate and a depressed conception rate. Other evidence included an increased susceptibility of first lactation cows to abortion, a lower abortion rate in late pregnant dry cows fed more mature pasture, a 20% repeat abortion rate in the population sampled and the lack of conclusive evidence for infectious and selected non-infectious agents. There were no other observed clinical signs in most aborting cows. 相似文献
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Conclusions and summary Certain anatomical characters of flax stems are related to the fineness of the fibre strands obtained from the stems.The relationships established should assist in estimating potential quality of the fibre contained in small straw lots.
Zusammenfassung Eine Untersuchung der Beziehung zwischen den anatomischen Eigenschaften von Flachsstengeln und der Feinheit der Faserbänder, die von den Flachsstengeln hergestellt wurden, wird beschrieben.Bestimmte Zusammenhänge wurden beobachtet. Dieselben könnten wertvoll sein für diejenigen die sich für die Vorhersage der Fasergüte interessieren, wenn nur kleine Strohmengen zur Verfügung stehen.相似文献
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