Toward automatic reconstruction of a highly resolved tree of life     

Ciccarelli FD  Doerks T  von Mering C  Creevey CJ  Snel B  Bork P 《Science (New York, N.Y.)》2006,311(5765):1283-1287

We have developed an automatable procedure for reconstructing the tree of life with branch lengths comparable across all three domains. The tree has its basis in a concatenation of 31 orthologs occurring in 191 species with sequenced genomes. It revealed interdomain discrepancies in taxonomic classification. Systematic detection and subsequent exclusion of products of horizontal gene transfer increased phylogenetic resolution, allowing us to confirm accepted relationships and resolve disputed and preliminary classifications. For example, we place the phylum Acidobacteria as a sister group of delta-Proteobacteria, support a Gram-positive origin of Bacteria, and suggest a thermophilic last universal common ancestor.  相似文献   

Influenza mutation from equine to canine     

von Grotthuss M  Rychlewski L 《Science (New York, N.Y.)》2006,311(5765):1241-2; author reply 1241-2

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High resolution species distribution models of two nesting water bird species: a study of transferability and predictive performance     

Stefan Heinänen  Johnny Erola  Mikael von Numers 《Landscape Ecology》2012,27(4):545-555

Species distribution modelling is increasingly used in ecological studies and is particularly useful in conservation planning. Models are, however, typically created with a coarse resolution, although conservation planning often requires a high resolution. In this study we created high resolution models and explored central aspects of the modelling procedure; transferability and predictive performance of the models. We created models for two breeding water bird species, common eider Somateria mollissima and herring gull Larus argentatus, based on data from two regions in the Finnish archipelago (234 islands). We used seven variables which we considered as potential predictors of nest site location: distance to forest, distance to rock and distance to low vegetation, exposure, elevation, slope and curvature of the land surface. We tested the predictive ability of the models crosswise between the areas by using area under the receiver operating characteristic curve. The models were transferable between our study areas and the predictive performance varied from fair to excellent. The most important predictors overall were exposure and distance to forest. More general models, with higher regularization values in the Maxent software, had better transferability regarding predictive performance. However, when we fitted a model based on 60% of the data from both regions and evaluated the model on the remaining 40%, the most complex model had the highest accuracy. Extrapolation of SDMs, evaluated on data from the same region, should therefore always be done with caution as the most accurate model might not have the best transferability if it is not general enough.  相似文献   

Pediatric Clinical Pathology     

Benita von Dehn 《Veterinary Clinics of North America: Small Animal Practice》2014

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Development of a novel fracture fragment stabilization system for minimally invasive osteosynthesis and in vitro comparison to traditional Kern bone reduction forceps     

Dirsko J. F. von Pfeil DrMedVet  DVM  DACVS  DECVS  DACVSMR  Christopher Horstman DVM  DACVS  MBA 《Veterinary surgery : VS》2020,49(7):1350-1358

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A small‐scale open‐label study of the treatment of canine flea allergy dermatitis with fluralaner          下载免费PDF全文

Petr Fisara  Michael Shipstone  Andrew von Berky  Janet von Berky 《Veterinary dermatology》2015,26(6):417-e98

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Impact of land cover homogenization on the Corncrake (Crex crex) in traditional farmland     

Ine Dorresteijn  Lucas Teixeira  Henrik von Wehrden  Jacqueline Loos  Jan Hanspach  John Anton Robert Stein  Joern Fischer 《Landscape Ecology》2015,30(8):1483-1495

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Effects of increasing dietary rye levels on physicochemical characteristics of digesta and its impact on stomach emptying as well as the formation of ‘doughballs’ in stomachs of young pigs     

Volker Wilke  Richard Grone  Andreas von Felde  Amr Abd El-Wahab  Petra Wolf  Josef Kamphues 《Journal of animal physiology and animal nutrition》2021,105(Z1):19-25

Despite quite similar contents of starch and crude fibre of wheat and rye, the unique non-starch-polysaccharide fraction of rye (e.g. high levels of arabinoxylans and fructans) might have an impact on physicochemical properties of the digesta in pigs. Forty pigs (age: 46.8 ± 5.28 days; bodyweight: 16.1 ± 4.13 kg) were divided into four treatment groups. During four weeks, the pigs received diets consisting of wheat and/or rye, barley, soy, potato protein and a mineral supplement. The sum of wheat and rye was 69% in all diets, whereby the compound feed of each group was characterized by a different ratio (%) of wheat/rye (69/0; 46/23; 23/46; 0/69, respectively). In the stomach, ‘doughballs’ occurred more frequently with increasing dietary rye levels (9/10; 69% rye). With higher DM content and extract-viscosity of gastric digesta, the stomach emptying tended to be retarded in rye groups. Compared to the control group (69% wheat), maximum dietary rye levels (69%) resulted in significantly higher concentrations of lactic acid in digesta of the stomach and small intestine. With increasing lactic acid concentrations, the pH tended to be lower in small intestinal digesta. With an intensified formation of lactic acid, effects against Gram-negative bacteria, for example Salmonella, can be expected. Moreover, because of higher viscosity and the retarded stomach emptying, there could be advantages of including rye in compound feeds when a longer lasting satiety is intended, for example when feeding pregnant sows (regularly fed restrictively).  相似文献   

Carbon dynamics in a temperate grassland soil after 9 years exposure to elevated CO₂ (Swiss FACE)     

Zubin Xie  Georg Cadisch  Grant Edwards  Elizabeth M. Baggs 《Soil biology & biochemistry》2005,37(7):1387-1395

Elevated pCO₂ increases the net primary production, C/N ratio, and C input to the soil and hence provides opportunities to sequester CO₂-C in soils to mitigate anthropogenic CO₂. The Swiss 9 y grassland FACE (free air carbon-dioxide enrichment) experiment enabled us to explore the potential of elevated pCO₂ (60 Pa), plant species (Lolium perenne L. and Trifolium repens L.) and nitrogen fertilization (140 and 540 kg ha⁻¹ y⁻¹) on carbon sequestration and mineralization by a temperate grassland soil. Use of ¹³C in combination with respired CO₂ enabled the identification of the origins of active fractions of soil organic carbon. Elevated pCO₂ had no significant effect on total soil carbon, and total soil carbon was also independent of plant species and nitrogen fertilization. However, new (FACE-derived depleted ¹³C) input of carbon into the soil in the elevated pCO₂ treatments was dependent on nitrogen fertilization and plant species. New carbon input into the top 15 cm of soil from L. perennne high nitrogen (LPH), L. perenne low nitrogen (LPL) and T. repens low nitrogen (TRL) treatments during the 9 y elevated pCO₂ experiment was 9.3±2.0, 12.1±1.8 and 6.8±2.7 Mg C ha⁻¹, respectively. Fractions of FACE-derived carbon in less protected soil particles >53 μm in size were higher than in <53 μm particles. In addition, elevated pCO₂ increased CO₂ emission over the 118 d incubation by 55, 61 and 13% from undisturbed soil from LPH, LPL and TRL treatments, respectively; but only by 13, 36, and 18%, respectively, from disturbed soil (without roots). Higher input of new carbon led to increased decomposition of older soil organic matter (priming effect), which was driven by the quantity (mainly roots) of newly input carbon (L. perenne) as well as the quality of old soil carbon (e.g. higher recalcitrance in T. repens). Based on these results, the potential of well managed and established temperate grassland soils to sequester carbon under continued increasing concentrations of atmospheric CO₂ appears to be rather limited.  相似文献   

Long-term effects of ozone on Fagus sylvatica L. — An open-top chamber exposure study     

Georg H. M. Krause  Friedrich-Eberhard Höckel 《Water, air, and soil pollution》1995,85(3):1337-1342

The Landesumweltamt North-Rhine Westfalia is operating eight open-top chambers as well as six reference plots at a site on a westerly exposed slope (540 m a.s.) in the Egge mountains, 130 km northeast of the Ruhr area. Since 1991 eighteen 6 yr old beech trees (Fagus sylvatica L.) per plot/chamber were exposed either to ambient air (AA), non-filtered air (NF) or charcoal-filtered air. Ambient air pollutants (O3. SO2, NOx) as well as meteorological parameters were monitored continuously inside chambers as well as in the ambient. Growth parameters (bud development, stem diameter, shoot length, shoot diameter, leaf area, leaf colouration, leaf abscission) were assessed over the years 1992–1994.Even in the first year a marked earlier colouration of the leaves was observed in the NF (AOT 40=16.2 ppm·hr) versus the CF treatment (AOT 40=0.2 ppm·hr) and leaf abscission was two weeks earlier on NF-trees, indicating the common ozone effect of early senescence. Effects became more pronounced with increasing time of exposure. While hardly any effects on growth could be seen during the first and second year, shoot length and shoot diameter were reduced significantly by about 15 % in NF versus CF treatments in 1994. Similar effects were seen for the leaf area. No effects could be shown for bud development or stem diameter. Ozone specific symptoms were observed on individual trees in the NF and AA treatments and especially pronounced in 1994 (AOT 40=24.1 ppm·hr), but also to a much lesser extent in the CF-treatment. AOT40 value of 10 ppm·h, proposed as provisional standard for the protection of trees by UN-ECE seems to be stringent enough according to the results of this exposure study.  相似文献