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Abstract. One way in which a species' numbers may be estimated without direct counting is to predict their dispersion and density from more readily available habitat measures, such as landscape variables measured from maps or vegetation variables measured in the field. We compare the power of ordination and regression techniques for predicting badger ( Meles meles L.) numbers at a local scale, using a land class system, map-read landscape variables and field-derived vegetation variables. Sett density was used as a surrogate of badger density. Multiple linear regression using vegetation and landscape variables together gave the most accurate prediction of sett density, while ordination techniques were of lesser value. The addition of vegetation variables to landscape variables did not substantially improve the power of ordination. Outlier Sett Density was predicted more accurately, and by different variables, to Main Sett Density. The relationship between badger ecology and habitat variables that were useful in predicting sett density is discussed. 相似文献
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Jürgen Kriwet 《Pal?ontologische Zeitschrift》2002,76(1):117-123
The new pycnodont fishAnomoeodus pauciseriale is described. The single specimen consists of associated but disarticulated skeletal remains including the paired prearticulars,
some skull elements, remains of the pectoral girdle and the vertebral column. It comes from the White Chalk Formation (Upper
Cretaceous) of East Sussex near Lewes, England. The precise stratigraphic age and locality are not known. The specific identification
is based on characters of the prearticular dentitions because the other skeletal remains are not diagnostic. In contrast to
other species ofAnomoeodus, the new species is characterised by a combination of rather short prearticular dentitions with only four tooth rows, a comparable
low number of medial teeth, and the absence of intercalated teeth between tooth rows.
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Influences of extreme weather,climate and pesticide use on invertebrates in cereal fields over 42 years
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Julie A. Ewald Christopher J. Wheatley Nicholas J. Aebischer Stephen J. Moreby Simon J. Duffield Humphrey Q. P. Crick Michael B. Morecroft 《Global Change Biology》2015,21(11):3931-3950
Cereal fields are central to balancing food production and environmental health in the face of climate change. Within them, invertebrates provide key ecosystem services. Using 42 years of monitoring data collected in southern England, we investigated the sensitivity and resilience of invertebrates in cereal fields to extreme weather events and examined the effect of long‐term changes in temperature, rainfall and pesticide use on invertebrate abundance. Of the 26 invertebrate groups examined, eleven proved sensitive to extreme weather events. Average abundance increased in hot/dry years and decreased in cold/wet years for Araneae, Cicadellidae, adult Heteroptera, Thysanoptera, Braconidae, Enicmus and Lathridiidae. The average abundance of Delphacidae, Cryptophagidae and Mycetophilidae increased in both hot/dry and cold/wet years relative to other years. The abundance of all 10 groups usually returned to their long‐term trend within a year after the extreme event. For five of them, sensitivity to cold/wet events was lowest (translating into higher abundances) at locations with a westerly aspect. Some long‐term trends in invertebrate abundance correlated with temperature and rainfall, indicating that climate change may affect them. However, pesticide use was more important in explaining the trends, suggesting that reduced pesticide use would mitigate the effects of climate change. 相似文献
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Steven Gutteridge J.Paul G. Malthouse Robert C. Bray 《Journal of inorganic biochemistry》1979,11(4):355-360
The spectrum of the Rapid Mo(V) electron paramagnetic resonance signal from xanthine oxidase dissolved in 17O-enriched water is presented. Difference technqiues have been used to eliminate the 16O contribution. Clearly observed structure in the spectrum is attributed to moderately strong hyperfine coupling of one oxygen atom to molybdenum. Though complete interpretation of the spectrum has not been attempted, one component of A(17O) is about 1.6 mT. The possibility that the oxygen is present in a MoOH group, whose proton is the strongly-coupled proton of the Rapid signal, is discussed. 相似文献
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Discrimination between the binding sites of modulators of the H+-translocating ATPase activity in rat liver mitochondrial membranes 总被引:1,自引:0,他引:1
The properties of the components of the mitochondrial ATPase which interact with modulators of energy transduction have been examined. The chromatographic behavior and the size of the components which bind trialkyl tins, carbodiimides and uncouplers, have been shown to be different. However, they all appear to be proteolipids with apparent molecular weights around 10,000. On this basis it is proposed that these inhibitors act at different sites in the membrane sector of the ATP synthase of rat liver mitochondria. 相似文献
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