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The importance of accurate species databases is debated in the recent literature of biodiversity assessment, considering that limited resources for conservation could be better allocated to assessment based on cost effective biodiversity features. I aimed to provide an understanding of sampling bias and provide practical advice to minimize bias either before or after data collection. I used 10×10 km 2 UTM grid data for 121 land snail species to account for geographic and taxonomic sampling bias in Hungary. Sampling intensity corrected for species richness varied significantly among regions, although regions were not good predictors of sampling intensity. Residuals were significantly autocorrelated in 15 km distance, indicating small scale heterogeneity in sampling intensity compared to species richness. Sampling coverage and intensity were higher close to human settlements and sampling intensity was higher within protected areas than outside. Commonness of species was positively associated with sampling intensity, while some rare species were over-represented in the records. Sampling intensity of microsnails (<3 mm) was significantly lower than that of the more detectable large species (>15 mm). Systematic effects of the collecting methods used in malacological research may be responsible for these differences. Understanding causes of sampling bias may help to reduce its effects in ecological, biogeographical and conservation biological applications, and help to guide future research.
A többszeletes spirál-CT-berendezések széles körű alkalmazása és a perfúziós szoftverek bevezetése lehetővé tette az agyi véráramlás CT-vizsgálatát. Cél és módszerek: A szerzők ismertetik az agyi perfúziós CT-vizsgálatok elvét, technikáját, amelyet az elmúlt másfél évben 96 betegükön végzett vizsgálatuk tapasztalataival egészítenek ki. A folyamatos technikai fejlődés eredményeként a közeljövőben lehetővé válik a teljes agy perfúziós CT-vizsgálata. Következtetések: Az agy perfúziós CT-vizsgálata gyors, viszonylag olcsó és a stroke kórismézésében pontos diagnózist eredményez.
building frame Hall building by displacing (sorting) the frame structure : spatial coverage requires purlins or purlin rings on the edge. The rigidity is provided by the
provide full spatial coverage for the area to be mapped (the variables used for the analysis were treated as equal and grouped into factors for better sortability). The six main factor groups we determined are hydrometeorology, topography, soil, geology
