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53 result(s) for "Schmitt, Jörg Peter"
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Comparing Climate Impact Assessments for Rural Adaptation Planning in Germany and the Netherlands
The consensus nowadays is that there is a need to adapt to increasingly occurring climate impacts by means of adaptation plans. However, only a minority of European cities has an approved climate adaptation plan by now. To support stakeholder dialogue and decision-making processes in climate adaptation planning, a detailed spatial information and evidence base in terms of a climate impact assessment is needed. This article aims to compare the climate impact assessment done in the context of two regional climate change adaptation planning processes in a Dutch and a German region. To do so, a comparison of guidelines and handbooks, methodological approaches, available data, and resulting maps and products is conducted. Similarities and differences between the two approaches with a particular focus on the input and output of such analysis are identified and both processes are assessed using a set of previously defined quality criteria. Both studies apply a similar conceptualisation of climate impacts and focus strongly on issues concerning their visualisation and communication. At the same time, the methods of how climate impacts are calculated and mapped are quite different. The discussion and conclusion section highlights the need to systematically consider climatic and socio-economic changes when carrying out a climate impact assessment, to focus on a strong visualisation of results for different stakeholder groups, and to link the results to planning processes and especially funding opportunities.
Comparison of different rating scales for the use in Delphi studies: different scales lead to different consensus and show different test-retest reliability
Background Consensus-orientated Delphi studies are increasingly used in various areas of medical research using a variety of different rating scales and criteria for reaching consensus. We explored the influence of using three different rating scales and different consensus criteria on the results for reaching consensus and assessed the test-retest reliability of these scales within a study aimed at identification of global treatment goals for total knee arthroplasty (TKA). Methods We conducted a two-stage study consisting of two surveys and consecutively included patients scheduled for TKA from five German hospitals. Patients were asked to rate 19 potential treatment goals on different rating scales (three-point, five-point, nine-point). Surveys were conducted within a 2 week period prior to TKA, order of questions (scales and treatment goals) was randomized. Results Eighty patients (mean age 68 ± 10 years; 70% females) completed both surveys. Different rating scales (three-point, five-point and nine-point rating scale) lead to different consensus despite moderate to high correlation between rating scales (r = 0.65 to 0.74). Final consensus was highly influenced by the choice of rating scale with 14 (three-point), 6 (five-point), 15 (nine-point) out of 19 treatment goals reaching the pre-defined 75% consensus threshold. The number of goals reaching consensus also highly varied between rating scales for other consensus thresholds. Overall, concordance differed between the three-point (percent agreement [p] = 88.5%, weighted kappa [k] = 0.63), five-point ( p  = 75.3%, k = 0.47) and nine-point scale ( p  = 67.8%, k = 0.78). Conclusion This study provides evidence that consensus depends on the rating scale and consensus threshold within one population. The test-retest reliability of the three rating scales investigated differs substantially between individual treatment goals. This variation in reliability can become a potential source of bias in consensus studies. In our setting aimed at capturing patients’ treatment goals for TKA, the three-point scale proves to be the most reasonable choice, as its translation into the clinical context is the most straightforward among the scales. Researchers conducting Delphi studies should be aware that final consensus is substantially influenced by the choice of rating scale and consensus criteria.
Blue‐green fluorescence during hypersensitive cell death arises from phenylpropanoid deydrodimers
Infection of Arabidopsis with avirulent Pseudomonas syringae and exposure to nitrogen dioxide (NO2) both trigger hypersensitive cell death (HCD) that is characterized by the emission of bright blue‐green (BG) autofluorescence under UV illumination. The aim of our current work was to identify the BG fluorescent molecules and scrutinize their biosynthesis, localization, and functions during the HCD. Compared with wild‐type (WT) plants, the phenylpropanoid‐deficient mutant fah1 developed normal HCD except for the absence of BG fluorescence. Ultrahigh resolution metabolomics combined with mass difference network analysis revealed that WT but not fah1 plants rapidly accumulate dehydrodimers of sinapic acid, sinapoylmalate, 5‐hydroxyferulic acid, and 5‐hydroxyferuloylmalate during the HCD. FAH1‐dependent BG fluorescence appeared exclusively within dying cells of the upper epidermis as detected by microscopy. Saponification released dehydrodimers from cell wall polymers of WT but not fah1 plants. Collectively, our data suggest that HCD induction leads to the formation of free BG fluorescent dehydrodimers from monomeric sinapates and 5‐hydroxyferulates. The formed dehydrodimers move from upper epidermis cells into the apoplast where they esterify cell wall polymers. Possible functions of phenylpropanoid dehydrodimers are discussed.
Increasing atmospheric CO2 reduces metabolic and physiological differences between isoprene- and non-isoprene-emitting poplars
Isoprene, a volatile organic compound produced by some plant species, enhances abiotic stress tolerance under current atmospheric CO2 concentrations, but its biosynthesis is negatively correlated with CO2 concentrations. We hypothesized that losing the capacity to produce isoprene would require stronger up-regulation of other stress tolerance mechanisms at low CO2 than at higher CO2 concentrations. We compared metabolite profiles and physiological performance in poplars (Populus × canescens) with either wild-type or RNAi-suppressed isoprene emission capacity grown at pre-industrial low, current atmospheric, and future high CO2 concentrations (190, 390 and 590 ppm CO2, respectively). Suppression of isoprene biosynthesis led to significant rearrangement of the leaf metabolome, increasing stress tolerance responses such as xanthophyll cycle pigment de-epoxidation and antioxidant levels, as well as altering lipid, carbon and nitrogen metabolism. Metabolic and physiological differences between isoprene-emitting and suppressed lines diminished as growth CO2 concentrations rose. The CO2 dependence of our results indicates that the effects of isoprene biosynthesis are strongest at pre-industrial CO2 concentrations. Rising CO2 may reduce the beneficial effects of biogenic isoprene emission, with implications for species competition. This has potential consequences for future climate warming, as isoprene emitted from vegetation has strong effects on global atmospheric chemistry.
Mycorrhiza-Triggered Transcriptomic and Metabolomic Networks Impinge on Herbivore Fitness
Symbioses between plants and mycorrhizal fungi are ubiquitous in ecosystems and strengthen the plants' defense against aboveground herbivores. Here, we studied the underlying regulatory networks and biochemical mechanisms in leaves induced by ectomycorrhizae that modify herbivore interactions. Feeding damage and oviposition by the widespread poplar leaf beetle Chrysomela populi were reduced on the ectomycorrhizal hybrid poplar Populus × canescens. Integration of transcriptomics, metabolomics, and volatile emission patterns via mass difference networks demonstrated changes in nitrogen allocation in the leaves of mycorrhizal poplars, down-regulation of phenolic pathways, and up-regulation of defensive systems, including protease inhibitors, chitinases, and aldoxime biosynthesis. Ectomycorrhizae had a systemic influence on jasmonate-related signaling transcripts. Our results suggest that ectomycorrhizae prime wounding responses and shift resources from constitutive phenol-based to specialized protective compounds. Consequently, symbiosis with ectomycorrhizal fungi enabled poplars to respond to leaf beetle feeding with a more effective arsenal of defense mechanisms compared with nonmycorrhizal poplars, thus demonstrating the importance of belowground plant-microbe associations in mitigating aboveground biotic stress.
Metal Ion Concentrations in Body Fluids after Implantation of Hip Replacements with Metal-on-Metal Bearing – Systematic Review of Clinical and Epidemiological Studies
The use of metal-on-metal (MoM) total hip arthroplasty (THA) increased in the last decades. A release of metal products (i.e. particles, ions, metallo-organic compounds) in these implants may cause local and/or systemic adverse reactions. Metal ion concentrations in body fluids are surrogate measures of metal exposure. To systematically summarize and critically appraise published studies concerning metal ion concentrations after MoM THA. Systematic review of clinical trials (RCTs) and epidemiological studies with assessment of metal ion levels (cobalt, chromium, titanium, nickel, molybdenum) in body fluids after implantation of metalliferous hip replacements. Systematic search in PubMed and Embase in January 2012 supplemented by hand search. Standardized abstraction of pre- and postoperative metal ion concentrations stratified by type of bearing (primary explanatory factor), patient characteristics as well as study quality characteristics (secondary explanatory factors). Overall, 104 studies (11 RCTs, 93 epidemiological studies) totaling 9.957 patients with measurement of metal ions in body fluids were identified and analyzed. Consistently, median metal ion concentrations were persistently elevated after implantation of MoM-bearings in all investigated mediums (whole blood, serum, plasma, erythrocytes, urine) irrespective of patient characteristics and study characteristics. In several studies very high serum cobalt concentrations above 50 µg/L were measured (detection limit typically 0.3 µg/L). Highest metal ion concentrations were observed after treatment with stemmed large-head MoM-implants and hip resurfacing arthroplasty. Due to the risk of local and systemic accumulation of metallic products after treatment with MoM-bearing, risk and benefits should be carefully balanced preoperatively. The authors support a proposed \"time out\" for stemmed large-head MoM-THA and recommend a restricted indication for hip resurfacing arthroplasty. Patients with implanted MoM-bearing should receive regular and standardized monitoring of metal ion concentrations. Further research is indicated especially with regard to potential systemic reactions due to accumulation of metal products.
Pathway analysis of the transcriptome and metabolome of salt sensitive and tolerant poplar species reveals evolutionary adaption of stress tolerance mechanisms
Background Populus euphratica is a salt tolerant and Populus × canescens a salt sensitive poplar species. Because of low transcriptional responsiveness of P. euphratica to salinity we hypothesized that this species exhibits an innate activation of stress protective genes compared with salt sensitive poplars. To test this hypothesis, the transcriptome and metabolome of mature unstressed leaves of P. euphratica and P . × canescens were compared by whole genome microarray analyses and FT-ICR-MS metabolite profiling. Results Direct cross-species comparison of the transcriptomes of the two poplar species from phylogenetically different sections required filtering of the data set. Genes assigned to the GO slim categories 'mitochondria', 'cell wall', 'transport', 'energy metabolism' and 'secondary metabolism' were significantly enriched, whereas genes in the categories 'nucleus', 'RNA or DNA binding', 'kinase activity' and 'transcription factor activity' were significantly depleted in P. euphratica compared with P . × canescens . Evidence for a general activation of stress relevant genes in P. euphratica was not detected. Pathway analyses of metabolome and transcriptome data indicated stronger accumulation of primary sugars, activation of pathways for sugar alcohol production, and faster consumption of secondary metabolites in P. euphratica compared to P . × canescens . Physiological measurements showing higher respiration, higher tannin and soluble phenolic contents as well as enrichment of glucose and fructose in P. euphratica compared to P . × canescens corroborated the results of pathway analyses. Conclusion P. euphratica does not rely on general over-expression of stress pathways to tolerate salt stress. Instead, it exhibits permanent activation of control mechanisms for osmotic adjustment (sugar and sugar alcohols), ion compartmentalization (sodium, potassium and other metabolite transporters) and detoxification of reactive oxygen species (phenolic compounds). The evolutionary adaptation of P. euphratica to saline environments is apparently linked with higher energy requirement of cellular metabolism and a loss of transcriptional regulation.
Short-Term Exposure to Nitrogen Dioxide Provides Basal Pathogen Resistance
Nitrogen dioxide (NO₂) forms in plants under stress conditions, but little is known about its physiological functions. Here, we explored the physiological functions of NO₂ in plant cells using short-term fumigation of Arabidopsis (Arabidopsis thaliana) for 1 h with 10 μL L−1 NO₂. Although leaf symptoms were absent, the expression of genes related to pathogen resistance was induced. Fumigated plants developed basal disease resistance, or pattern-triggered immunity, against the necrotrophic fungus Botrytis cinerea and the hemibiotrophic bacterium Pseudomonas syringae. Functional salicylic acid and jasmonic acid (JA) signaling pathways were both required for the full expression of NO₂-induced resistance against B. cinerea. An early peak of salicylic acid accumulation immediately after NO₂ exposure was followed by a transient accumulation of oxophytodienoic acid. The simultaneous NO₂-induced expression of genes involved in jasmonate biosynthesis and jasmonate catabolism resulted in the complete suppression of JA and JA-isoleucine (JA-Ile) accumulation, which was accompanied by a rise in the levels of their catabolic intermediates 12-OH-JA, 12-OH-JA-Ile, and 12-COOH-JA-Ile. NO₂-treated plants emitted the volatile monoterpene 𝛼-pinene and the sesquiterpene longifolene (syn. junipene), which could function in signaling or direct defense against pathogens. NO₂-triggered B. cinerea resistance was dependent on enhanced early callose deposition and CYTOCHROME P450 79B2 (CYP79B2), CYP79B3, and PHYTOALEXIN DEFICIENT3 gene functions but independent of camalexin, CYP81F2, and 4-OH-indol-3-ylmethylglucosinolate derivatives. In sum, exogenous NO₂ triggers basal pathogen resistance, pointing to a possible role for endogenous NO₂ in defense signaling. Additionally, this study revealed the involvement of jasmonate catabolism and volatiles in pathogen immunity.
Mycorrhiza-Tree-Herbivore Interactions: Alterations in Poplar Metabolome and Volatilome
Plants are continuously interacting with other organisms to optimize their performance in a changing environment. Mycorrhization is known to affect the plant growth and nutrient status, but it also can lead to adjusted plant defense and alter interactions with other trophic levels. Here, we studied the effect of Laccaria bicolor-mycorrhization on the poplar (Populus x canescens) metabolome and volatilome on trees with and without a poplar leaf beetle (Chrysomela populi) infestation. We analyzed the leaf and root metabolomes employing liquid chromatography–mass spectrometry, and the leaf volatilome employing headspace sorptive extraction combined with gas-chromatography–mass spectrometry. Mycorrhization caused distinct metabolic adjustments in roots, young/infested leaves and old/not directly infested leaves. Mycorrhization adjusted the lipid composition, the abundance of peptides and, especially upon herbivory, the level of various phenolic compounds. The greatest change in leaf volatile organic compound (VOC) emissions occurred four to eight days following the beetle infestation. Together, these results prove that mycorrhization affects the whole plant metabolome and may influence poplar aboveground interactions. The herbivores and the mycorrhizal fungi interact with each other indirectly through a common host plant, a result that emphasizes the importance of community approach in chemical ecology.
Biodiversity at multiple trophic levels is needed for ecosystem multifunctionality
Both a high number of species and abundance in multiple trophic levels are required for ecosystems to continue to provide the services humans require of them. The importance of biodiversity in depth Numerous experiments have shown that the loss of biodiversity within single trophic groups — groups of organisms consuming resources from a similar level in the food chain — reduces the ability of ecosystems to deliver the services on which humans depend. How the loss of biodiversity in natural ecosystems consisting of multiple interacting trophic groups affects ecosystem functioning has remained unclear. Santiago Soliveres et al . have compiled data on the richness and abundance of 4,600 microbial, plant and animal taxa in 150 grasslands in Germany, together with information on 14 ecosystem services. Their analysis of the data demonstrates that biodiversity across multiple trophic groups is as important for the functioning of ecosystems as land-use intensity or environmental conditions. They conclude that the preservation of high levels of richness and diversity within a wide range of taxa will be key to ensuring that ecosystems continue to deliver the services on which humans rely. The findings also inform conservation and ecosystem management strategies by highlighting the most functionally relevant organisms, which include plants, soil bacteria and herbivorous insects. Many experiments have shown that loss of biodiversity reduces the capacity of ecosystems to provide the multiple services on which humans depend 1 , 2 . However, experiments necessarily simplify the complexity of natural ecosystems and will normally control for other important drivers of ecosystem functioning, such as the environment or land use. In addition, existing studies typically focus on the diversity of single trophic groups, neglecting the fact that biodiversity loss occurs across many taxa 3 , 4 and that the functional effects of any trophic group may depend on the abundance and diversity of others 5 , 6 . Here we report analysis of the relationships between the species richness and abundance of nine trophic groups, including 4,600 above- and below-ground taxa, and 14 ecosystem services and functions and with their simultaneous provision (or multifunctionality) in 150 grasslands. We show that high species richness in multiple trophic groups (multitrophic richness) had stronger positive effects on ecosystem services than richness in any individual trophic group; this includes plant species richness, the most widely used measure of biodiversity. On average, three trophic groups influenced each ecosystem service, with each trophic group influencing at least one service. Multitrophic richness was particularly beneficial for ‘regulating’ and ‘cultural’ services, and for multifunctionality, whereas a change in the total abundance of species or biomass in multiple trophic groups (the multitrophic abundance) positively affected supporting services. Multitrophic richness and abundance drove ecosystem functioning as strongly as abiotic conditions and land-use intensity, extending previous experimental results 7 , 8 to real-world ecosystems. Primary producers, herbivorous insects and microbial decomposers seem to be particularly important drivers of ecosystem functioning, as shown by the strong and frequent positive associations of their richness or abundance with multiple ecosystem services. Our results show that multitrophic richness and abundance support ecosystem functioning, and demonstrate that a focus on single groups has led to researchers to greatly underestimate the functional importance of biodiversity.