Refine
Year of publication
Document Type
- Article (15)
Has Fulltext
- yes (15)
Is part of the Bibliography
- no (15)
Keywords
- Ellenberg indicator values (2)
- RNA (2)
- 19F (1)
- Arrhenatheretum elatioris (1)
- Covid19-nmr (1)
- DNA-PAINT (1)
- Data sharing (1)
- Eutrophierung (1)
- FBS (1)
- Festuco-Brometea (1)
Central European temperate forests are – with the exception of floodplain forests – relatively little invaded by alien plants. However, despite substantial recent progress, there is still a lack of using vege-tation plot data for analyzing spatio-temporal patterns of alien tree species invasions.
We calculated relevé-based metrics of tree species’ ecological preferences using 19,413 phytosociological forest relevés of the Austrian vegetation database. We focused on the five most widely distributed alien trees, i.e. two archaeophytes (Castanea sativa, Juglans regia) and three neophytes (Acer negundo, Ailanthus altissima, Robinia pseudoacacia). For each of these species we analyzed the mean cover in the tree layer and the occurrence in the herb and shrub layers in relevés colonized by adult trees as a measure for persistence. Further, we evaluated the intergenerational ecological plasticity (= the ability of young trees to grow under different site conditions than adults) for the tree species, and the mean relevé indicator values for light, nutrients, moisture and hemeroby. We then compared these alien and native tree species metrics.
We found that A. altissima and R. pseudoacacia build up high mean cover values in invaded forests, but this was not the case for the other alien trees. Thus, both species strongly affected forest communities of invaded sites. Similarly, the two species were common in the lower vegetation layers indicating recruitment under the canopy of adult conspecifics; this was facilitated by their ability to produce root suckers. Highest values of inter-generational ecological plasticity occurred in native pioneer trees and species of softwood floodplain forests, while alien trees had moderately high (A. negundo, A. altissima, J. regia) to low values (C. sativa, R. pseudoacacia). With the exception of C. sativa, all alien species showed high mean Ellenberg indicator values for light and nutrients, and were more common in sites with high hemeroby and high mean Ellenberg indicator values for temperature. Distinct from the ecological preferences of alien trees, and thus rarely invaded, were montane beech forests, coniferous mountain forests and forests at extremely dry sites, as well as swamp and bog forests dominated by willows and ash.
We conclude that relevé-based metrics of the behavior of alien tree species allow new insights into the spatio-temporal dynamics of invasion of woody species in forests. Future work should expand this approach, e.g., by considering the role of life history traits and actual site conditions.
Durch einen Vergleich nach ca. 30 Jahren wiederholter Vegetationsaufnahmen von Glatthaferwiesen an Straßenrändern des Raumes Halle/S. konnten die in der Zwischenzeit stattgefundenen anthropogenen Veränderungen der straßenbegleitenden Vegetation am konkreten Beispiel belegt werden. Zur Interpretation der Veränderungen in der Artenzusammensetzung wurden besonders Zeigerwert-, Hemerobie- und Strategietypenspektren herangezogen. Veränderungen äußern sich vor allem in einer Abnahme der Diversität durch Zunahme euryöker Ubiquisten und einer Erhöhung des Hemerobiegrades. Die Ursachen für diesen Wandel sind besonders in der Intensivierung der Produktion auf den angrenzenden landwirtschaftlichen Nutzflächen und einer weitestgehenden Auflassung der Nutzung der Straßenränder selbst zu sehen, die sich in deren Eutrophierung äußern.
Semi-dry grasslands were once widely distributed communities, but today they represent some of the most vulnerable habitats in Central Europe. European and national legislation and non-governmental organizations have managed to protect some of the remaining fragments. However, despite their status as Natura 2000 habitats, they are often endangered due to improper management, fragmentation and edge effects from adjacent croplands. By using a sample of 44 semi-dry hay meadows in the south-eastern Alpine Foreland of Styria, we investigated how species-richness and trait composition of semi-dry grassland species respond to variation in patch size, connectivity, abiotic site factors and management regimes. We used linear regression models to identify the most important drivers for richness of typical semi-dry grassland species and thus conservation value. The number of typical semi-dry grassland species was highest in well-connected fragments, i.e. units that shared two or more borders with neighbouring species-rich grasslands. Furthermore, large semi-dry grasslands (> 8000 m²) had highest numbers of semi-dry grassland species and highest relevance for conservation; no difference was found among smaller fragment sizes. Unregular management was associated with increased presence of competitive species which replaced stress-tolerant specialists. Our study indicates that under eutrophication, small fragment size and isolation, only large semi-dry grasslands can sustain a high number of species with high conservation value. The conservation value of smaller semi-dry grassland fragments could be improved by buffer zones, adapted mowing treatments and periodical sheep grazing.
The Feldbach district is situated near the town of Feldbach in the southeastern province of Styria, Austria. Since 2007, a climate observation network of 151 climate stations within an area of approximately 20 x 15 km (grid cell 1.4 × 1.4 km) has provided a unique collection of spatial and temporal meteorological data. Examining short-lived ruderal and arable weed communities, we search for correlations and spatial patterns between the community composition and climate data. Do such plant communities respond to temperature differences within an agricultural landscape and on a regional scale? Data of 277 relevés from short-lived weed communities were collected across the investigated area during the summer of 2011. Relevés were assigned to the corresponding climate stations and classified. Average Ellenberg indicator values for temperature were calculated for each relevé and community cluster. Measured temperature data were assigned and correlated with community data by applying linear regression and redundancy analyses (RDA). The classification resulted in six associations; the two most frequently observed associations were divided into subtypes resulting in 13 vegetation clusters that could be analyzed further. A significant relationship could be found only between the clusters of arable weed communities and the average winter temperatures. Site variables explain twice as much variance as measured climate variables; this ratio changes to 50 : 50 when we analyzed only arable field community data. No clear spatial patterns concerning mean annual temperature were visible. However, the Setaria faberi subtype of the Echinochloo-Setarietum and the Sorghum halepense subtype of the Convolvulo-Agropyretum show a tendency toward a temperature-induced spatial pattern, such that both were sensitive to winter temperature. On a regional scale, the occurrence and composition of short-lived ruderal plant communities correlated weakly with climate variables. However, the studied arable weed communities showed a certain tendency to follow small-scale temperature differences, especially those of average winter temperature. We conclude that short-lived weed communities have the potential to be indicators for global warming, but the spatial temperature gradients are not clear enough in our approach to allow the production of better regression models and elucidation of distinct spatial patterns.
Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species’ threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.
Unter diesem Titel trafen sich mehr als 180 Tagungsgäste aus allen botanischen Gruppierungen - Naturschutzfachvereinigungen, Universitätsinstitute, Sammlungen, Behörden und Ämter sowie Freiberufliche - vom 18. bis 20. November 2005 im Göttinger Albrecht-von-Haller-Institut für Pflanzenwissenschaften der Georg-August-Universität. Eingeladen hatte die Abteilung Vegetationsanalyse und Phytodiversität (Erwin Bergmeier) des AvH-Instituts und der Bundesfachausschuss Botanik des NABU in Zusammenarbeit mit den botanischen Vereinigungen der Länder (Christian Berg, Michael Ristow). Ausgangspunkt der Tagung war die Einsicht, es mangele in Deutschland zunehmend an Strukturen, um Konzepte und Ziele aufzugreifen, die im internationalen Naturschutz angestoßen worden sind, und sie als Chancen zu nutzen. So sind die Ziele der ,Globalen Strategie zum Schutz der Pflanzenwelt' (Global Strategy for Plant Conservation, GSPC), dem wohl wichtigsten Instrument des internationalen Florenschutzes, bei uns noch viel zu wenig bekannt. Auch fehlt ein nationales Forum, in dem Ideen und Erfahrungen im botanischen Naturschutz ausgetauscht werden können. Ziel der Tagung war es daher, Wege zur Umsetzung der GSPC zu diskutieren und allgemein einen Prozess in Gang zu bringen, um den Informations- und Ideenaustausch zu verbessern, eben ein Netzwerk für alle, die dem Florenschutz verpflichtet sind, zu fördern.
We report here the nuclear magnetic resonance 19F screening of 14 RNA targets with different secondary and tertiary structure to systematically assess the druggability of RNAs. Our RNA targets include representative bacterial riboswitches that naturally bind with nanomolar affinity and high specificity to cellular metabolites of low molecular weight. Based on counter-screens against five DNAs and five proteins, we can show that RNA can be specifically targeted. To demonstrate the quality of the initial fragment library that has been designed for easy follow-up chemistry, we further show how to increase binding affinity from an initial fragment hit by chemistry that links the identified fragment to the intercalator acridine. Thus, we achieve low-micromolar binding affinity without losing binding specificity between two different terminator structures.
Background: To perform a comprehensive study on the relationship between vitamin D metabolism and the response to interferon-α-based therapy of chronic hepatitis C.
Methodology/Principal Findings: Associations between a functionally relevant polymorphism in the gene encoding the vitamin D 1α-hydroxylase (CYP27B1-1260 rs10877012) and the response to treatment with pegylated interferon-α (PEG-IFN-α) and ribavirin were determined in 701 patients with chronic hepatitis C. In addition, associations between serum concentrations of 25-hydroxyvitamin D3 (25[OH]D3) and treatment outcome were analysed. CYP27B1-1260 rs10877012 was found to be an independent predictor of sustained virologic response (SVR) in patients with poor-response IL28B genotypes (15% difference in SVR for rs10877012 genotype AA vs. CC, p = 0.02, OR = 1.52, 95% CI = 1.061–2.188), but not in patients with favourable IL28B genotype. Patients with chronic hepatitis C showed a high prevalence of vitamin D insufficiency (25[OH]D3<20 ng/mL) during all seasons, but 25(OH)D3 serum levels were not associated with treatment outcome.
Conclusions/Significance: Our study suggests a role of bioactive vitamin D (1,25[OH]2D3, calcitriol) in the response to treatment of chronic hepatitis C. However, serum concentration of the calcitriol precursor 25(OH)D3 is not a suitable predictor of treatment outcome.
Background: Vitamin D insufficiency has been associated with the occurrence of various types of cancer, but causal relationships remain elusive. We therefore aimed to determine the relationship between genetic determinants of vitamin D serum levels and the risk of developing hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC).
Methodology/Principal Findings: Associations between CYP2R1, GC, and DHCR7 genotypes that are determinants of reduced 25-hydroxyvitamin D (25[OH]D3) serum levels and the risk of HCV-related HCC development were investigated for 1279 chronic hepatitis C patients with HCC and 4325 without HCC, respectively. The well-known associations between CYP2R1 (rs1993116, rs10741657), GC (rs2282679), and DHCR7 (rs7944926, rs12785878) genotypes and 25(OH)D3 serum levels were also apparent in patients with chronic hepatitis C. The same genotypes of these single nucleotide polymorphisms (SNPs) that are associated with reduced 25(OH)D3 serum levels were found to be associated with HCV-related HCC (P = 0.07 [OR = 1.13, 95% CI = 0.99–1.28] for CYP2R1, P = 0.007 [OR = 1.56, 95% CI = 1.12–2.15] for GC, P = 0.003 [OR = 1.42, 95% CI = 1.13–1.78] for DHCR7; ORs for risk genotypes). In contrast, no association between these genetic variations and liver fibrosis progression rate (P>0.2 for each SNP) or outcome of standard therapy with pegylated interferon-α and ribavirin (P>0.2 for each SNP) was observed, suggesting a specific influence of the genetic determinants of 25(OH)D3 serum levels on hepatocarcinogenesis.
Conclusions/Significance: Our data suggest a relatively weak but functionally relevant role for vitamin D in the prevention of HCV-related hepatocarcinogenesis.
Background and Aims: The prevalence of hepatitis C virus (HCV) antibodies in Germany has been estimated to be in the range of 0.4–0.63%. Screening for HCV is recommended in patients with elevated ALT levels or significant risk factors for HCV transmission only. However, 15–30% of patients report no risk factors and ALT levels can be normal in up to 20–30% of patients with chronic HCV infection. The aim of this study was to assess the HCV seroprevalence in patients visiting two tertiary care emergency departments in Berlin and Frankfurt, respectively.
Methods: Between May 2008 and March 2010, a total of 28,809 consecutive patients were screened for the presence of anti-HCV antibodies. Anti-HCV positive sera were subsequently tested for HCV-RNA.
Results: The overall HCV seroprevalence was 2.6% (95% CI: 2.4–2.8; 2.4% in Berlin and 3.5% in Frankfurt). HCV-RNA was detectable in 68% of anti-HCV positive cases. Thus, the prevalence of chronic HCV infection in the overall study population was 1.6% (95% CI 1.5–1.8). The most commonly reported risk factor was former/current injection drug use (IDU; 31.2%) and those with IDU as the main risk factor were significantly younger than patients without IDU (p<0.001) and the male-to-female ratio was 72% (121 vs. 46 patients; p<0.001). Finally, 18.8% of contacted HCV-RNA positive patients had not been diagnosed previously.
Conclusions: The HCV seroprevalence was more than four times higher compared to current estimates and almost one fifth of contacted HCV-RNA positive patients had not been diagnosed previously.
DNA methylation profiles of aggressive behavior may capture lifetime cumulative effects of genetic, stochastic, and environmental influences associated with aggression. Here, we report the first large meta-analysis of epigenome-wide association studies (EWAS) of aggressive behavior (N = 15,324 participants). In peripheral blood samples of 14,434 participants from 18 cohorts with mean ages ranging from 7 to 68 years, 13 methylation sites were significantly associated with aggression (alpha = 1.2 × 10−7; Bonferroni correction). In cord blood samples of 2425 children from five cohorts with aggression assessed at mean ages ranging from 4 to 7 years, 83% of these sites showed the same direction of association with childhood aggression (r = 0.74, p = 0.006) but no epigenome-wide significant sites were found. Top-sites (48 at a false discovery rate of 5% in the peripheral blood meta-analysis or in a combined meta-analysis of peripheral blood and cord blood) have been associated with chemical exposures, smoking, cognition, metabolic traits, and genetic variation (mQTLs). Three genes whose expression levels were associated with top-sites were previously linked to schizophrenia and general risk tolerance. At six CpGs, DNA methylation variation in blood mirrors variation in the brain. On average 44% (range = 3–82%) of the aggression–methylation association was explained by current and former smoking and BMI. These findings point at loci that are sensitive to chemical exposures with potential implications for neuronal functions. We hope these results to be a starting point for studies leading to applications as peripheral biomarkers and to reveal causal relationships with aggression and related traits.
Background: IL28B gene polymorphism is the best baseline predictor of response to interferon alfa-based antiviral therapies in chronic hepatitis C. Recently, a new IFN-L4 polymorphism was identified as first potential functional variant for induction of IL28B expression. Individualization of interferon alfa-based therapies based on a combination of IL28B/IFN-L4 polymorphisms may help to optimize virologic outcome and economic resources.
Methods: Optimization of treatment outcome prediction was assessed by combination of different IL28B and IFN-L4 polymorphisms in patients with chronic HCV genotype 1 (n = 385), 2/3 (n = 267), and 4 (n = 220) infection treated with pegylated interferon alfa (PEG-IFN) and ribavirin with (n = 79) or without telaprevir. Healthy people from Germany (n = 283) and Egypt (n = 96) served as controls.
Results: Frequencies of beneficial IL28B rs12979860 C/C genotypes were lower in HCV genotype 1/4 infected patients in comparison to controls (20–35% vs. 46–47%) this was also true for ss469415590 TT/TT (20–35% vs. 45–47%). Single interferon-lambda SNPs (rs12979860, rs8099917, ss469415590) correlated with sustained virologic response (SVR) in genotype 1, 3, and 4 infected patients while no association was observed for genotype 2. Interestingly, in genotype 3 infected patients, best SVR prediction was based on IFN-L4 genotype. Prediction of SVR with high accuracy (71–96%) was possible in genotype 1, 2, 3 and 4 infected patients who received PEG-IFN/ribavirin combination therapy by selection of beneficial IL28B rs12979860 C/C and/or ss469415590 TT/TT genotypes (p<0.001). For triple therapy with first generation protease inhibitors (PIs) (boceprevir, telaprevir) prediction of high SVR (90%) rates was based on the presence of at least one beneficial genotype of the 3 IFN-lambda SNPs.
Conclusion: IFN-L4 seems to be the best single predictor of SVR in genotype 3 infected patients. For optimized prediction of SVR by treatment with dual combination or first generation PI triple therapies, grouping of interferon-lambda haplotypes may be helpful with positive predictive values of 71–96%.
Background: Different parameters have been determined for prediction of treatment outcome in hepatitis c virus genotype 1 infected patients undergoing pegylated interferon, ribavirin combination therapy. Results on the importance of vitamin D levels are conflicting. In the present study, a comprehensive analysis of vitamin D levels before and during therapy together with single nucleotide polymorphisms involved in vitamin D metabolism in the context of other known treatment predictors has been performed.
Methods: In a well characterized prospective cohort of 398 genotype 1 infected patients treated with pegylated interferon-α and ribavirin for 24–72 weeks (INDIV-2 study) 25-OH-vitamin D levels and different single nucleotide polymorphisms were analyzed together with known biochemical parameters for a correlation with virologic treatment outcome.
Results: Fluctuations of more than 5 (10) ng/ml in 25-OH-vitamin D-levels have been observed in 66 (39) % of patients during the course of antiviral therapy and neither pretreatment nor under treatment 25-OH-vitamin D-levels were associated with treatment outcome. The DHCR7-TT-polymorphism within the 7-dehydrocholesterol-reductase showed a significant association (P = 0.031) to sustained viral response in univariate analysis. Among numerous further parameters analyzed we found that age (OR = 1.028, CI = 1.002–1.056, P = 0.035), cholesterol (OR = 0.983, CI = 0.975–0.991, P<0.001), ferritin (OR = 1.002, CI = 1.000–1.004, P = 0.033), gGT (OR = 1.467, CI = 1.073–2.006, P = 0.016) and IL28B-genotype (OR = 2.442, CI = 1.271–4.695, P = 0.007) constituted the strongest predictors of treatment response.
Conclusions: While 25-OH-vitamin D-levels levels show considerable variations during the long-lasting course of antiviral therapy they do not show any significant association to treatment outcome in genotype 1 infected patients.
SARS-CoV-2 contains a positive single-stranded RNA genome of approximately 30 000 nucleotides. Within this genome, 15 RNA elements were identified as conserved between SARS-CoV and SARS-CoV-2. By nuclear magnetic resonance (NMR) spectroscopy, we previously determined that these elements fold independently, in line with data from in vivo and ex-vivo structural probing experiments. These elements contain non-base-paired regions that potentially harbor ligand-binding pockets. Here, we performed an NMR-based screening of a poised fragment library of 768 compounds for binding to these RNAs, employing three different 1H-based 1D NMR binding assays. The screening identified common as well as RNA-element specific hits. The results allow selection of the most promising of the 15 RNA elements as putative drug targets. Based on the identified hits, we derive key functional units and groups in ligands for effective targeting of the RNA of SARS-CoV-2.
Poster presentation: Background Maraviroc is a new drug used to treat HIV infection from the new class of drugs called CCR5 entry inhibitors. As the active principle of these drugs is to block the CCR5-receptor on the surface of the target cells, it has to be known if the virus in the patient is using only CCR5 as co-receptor or if there are populations that can also use CXCR4. Therefore, an assay to determine the tropism has to be performed before starting a therapy. Besides phenotypic assays like the TROFILE® assay by Monogram, used in the approval studies, there exist several genotyping systems like geno2pheno-coreceptor, Wetcat (providing five different genotypic tropism schemes) and WebPSSM. ...