Microbial CH4 and N2O Consumption in Acidic Wetlands

Acidic wetlands are global sources of the atmospheric greenhouse gases methane (CH4), and nitrous oxide (N2O). Consumption of both atmospheric gases has been observed in various acidic wetlands, but information on the microbial mechanisms underlying these phenomena is scarce. A substantial amount of CH4 is consumed in sub soil by aerobic methanotrophs at anoxic–oxic interfaces (e.g., tissues of Sphagnum mosses, rhizosphere of vascular plant roots). Methylocystis-related species are likely candidates that are involved in the consumption of atmospheric CH4 in acidic wetlands. Oxygen availability regulates the activity of methanotrophs of acidic wetlands. Other parameters impacting on the methanotroph-mediated CH4 consumption have not been systematically evaluated. N2O is produced and consumed by microbial denitrification, thus rendering acidic wetlands as temporary sources or sinks for N2O. Denitrifier communities in such ecosystems are diverse, and largely uncultured and/or new, and environmental factors that control their consumption activity are unresolved. Analyses of the composition of N2O reductase genes in acidic wetlands suggest that acid-tolerant Proteobacteria have the potential to mediate N2O consumption in such soils. Thus, the fragmented current state of knowledge raises open questions concerning methanotrophs and denitrifiers that consume atmospheric CH4 and N2O in acidic wetlands

Indentation creep testing of superalloys

Great progress has been made over the last years in high temperature nanoindentation testing and quite reliable test systems are available to operate at temperatures up to 800°C. With such systems the high temperature strength is measured via the hardness of materials. However, for high temperature materials especially the creep strength is of interest and therefore also many attempts have been undergone to probe also the creep properties with high temperature nanoindentation. In most cases pointed indenters as Berkovich or conical indenters have been used for this. A major challenge, however, then is, how the nanoindentation data are converted into uniaxial creep properties, i.e. those which are needed for constructional purposes. Although, it seems that the stress exponent can be derived quite successfully with such indenters, an evaluation of a full creep curve for materials with significant primary creep does not seem possible, since the strain a pointed indenter is inducing is fixed by the indenter shape and stays more or less constant during the whole test [1]. Please click Additional Files below to see the full abstract

Response of the wheat mycobiota to flooding revealed substantial shifts towards plant pathogens

Rainfall extremes are intensifying as a result of climate change, leading to increased flood risk. Flooding affects above- and belowground ecosystem processes, representing a substantial threat to crop productivity under climate change. Plant-associated fungi play important roles in plant performance, but their response to abnormal rain events is unresolved. Here, we established a glasshouse experiment to determine the effects of flooding stress on the spring wheat-mycobiota complex. Since plant phenology could be an important factor in the response to hydrological stress, flooding was induced only once and at different plant growth stages, such as tillering, booting and flowering. We assessed the wheat mycobiota response to flooding in three soil-plant compartments (phyllosphere, roots and rhizosphere) using metabarcoding. Key soil and plant traits were measured to correlate physiological plant and edaphic changes with shifts in mycobiota structure and functional guilds. Flooding reduced plant fitness, and caused dramatic shifts in mycobiota assembly across the entire plant. Notably, we observed a functional transition consisting of a decline in mutualist abundance and richness with a concomitant increase in plant pathogens. Indeed, fungal pathogens associated with important cereal diseases, such as Gibberella intricans, Mycosphaerella graminicola, Typhula incarnata and Olpidium brassicae significantly increased their abundance under flooding. Overall, our study demonstrate the detrimental effect of flooding on the wheat mycobiota complex, highlighting the urgent need to understand how climate change-associated abiotic stressors alter plant-microbe interactions in cereal crops.Peer Reviewe

Space-time evolution of bulk QCD matter

We introduce a combined fully three-dimensional macroscopic/microscopic transport approach employing relativistic 3D-hydrodynamics for the early, dense, deconfined stage of the reaction and a microscopic non-equilibrium model for the later hadronic stage where the equilibrium assumptions are not valid anymore. Within this approach we study the dynamics of hot, bulk QCD matter, which is being created in ultra-relativistic heavy ion collisions at RHIC. Our approach is capable of self-consistently calculating the freezeout of the hadronic system, while accounting for the collective flow on the hadronization hypersurface generated by the QGP expansion. In particular, we perform a detailed analysis of the reaction dynamics, hadronic freezeout, and transverse flow.Comment: 24 pages, 27 figure

Presseförderung als Mittel gegen Medienkonzentration und für die publizistische Vielfalt? Quasi-experimentelle Untersuchung der Schweiz im Vergleich zu Belgien, Österreich, Irland sowie Deutschland

Mass media play a certain role for society in democratic systems. Communication research faces this role by analyzing media performance. Well performing media provide the society with a diversity of topics, opinions, and sources. Mostly economically driven processes of media concentration endanger media diversity by decreasing the amount of independent media companies most probably causing less diverse media content. To counteract processes of media concentration in the field of daily newspapers many countries have established various kinds of press subsidies. This study examines empirically what kind of impact press subsidies have on media concentration. It uses a quasi-experimental desig

Veränderung audiovisueller Produktionen durch geänderte Finanzierungsweise

Non-lineare Anbieter von audiovisuellen Inhalten, wie beispielweise Netflix, erfreuen sich einer zunehmenden Beliebtheit auf dem digitalisierten Medienmarkt. Im Vergleich zu linearen Fernsehanbietern verfügen sie aber nur über beschränkte Einnahmequellen, weswegen die Vermutung naheliegt, dass sie alternative Finanzierungswege finden müssen. Hierbei könnten Produktplatzierungen in Eigenproduktionen eine maßgebliche Einnahmequelle für non-lineare Anbieter darstellen. Daher wurde in einer Vor- und einer Hauptstudie das Vorkommen von Produktplatzierungen in Eigenproduktionen von Netflix und linearen Fernsehanbietern inhaltsanalytisch untersucht. Die Ergebnisse zeigen, dass Produktplatzierungen in Produktionen non-linearer Anbieter häufiger und länger gezeigt werden als bei linearen Anbietern. Unterschiede zeigten sich außerdem in der Darstellungsgröße sowie der Platzierung im Raum. Hinsichtlich der Einbeziehung der Produkte in den Ablauf und die Handlung der Szene wurde festgestellt, dass die überwiegende Mehrheit der Produktplatzierungen sowohl bei linearen als bei non-linearen Produktionen in den Ablauf und die Handlung der Szene integriert wurde. Zentrale Einschränkungen der vorgestellten Studien sind die Nichtnachweisbarkeit von Entgeltleistungen von Produktplatzierungen durch inhaltsanalytische Arbeiten sowie die begrenzte Aussagekraft der Studien aufgrund der Fallauswahl. Dennoch stellen die Ergebnisse wegen der häufigeren Verwendung von Produktplatzierungen in non-linearem Fernsehen einen wichtigen Anstoß für weitere Forschung dar

Editorial: The Impact of Microorganisms on Consumption of Atmospheric Trace Gases

Editorial on the Research Topic: The Impact of Microorganisms on Consumption of Atmospheric Trace Gase

Trichoderma spp.-mediated mitigation of heat, stress, and their combination on the Arabidopsis thaliana holobiont: a metabolomics and metabarcoding approach

IntroductionThe use of substances to increase productivity and resource use efficiency is now essential to face the challenge of feeding the rising global population with the less environmental impact on the ecosystems. Trichoderma-based products have been used as biopesticides, to inhibit pathogenic microorganisms, and as biostimulants for crop growth, nutrient uptake promotion, and resistance to abiotic stresses.MethodsIn this work, plant metabolomics combined with roots and rhizosphere bacterial metabarcoding were exploited to inspect the performance of Trichoderma spp. biostimulants on Arabidopsis thaliana under drought, heat and their combination and its impact on plant holobiont.Results and discussionAn overall modulation of N-containing compounds, phenylpropanoids, terpenes and hormones could be pointed out by metabolomics. Moreover, metabarcoding outlined an impact on alpha and beta-diversity with an abundance of Proteobacteria, Pseudomonadales, Burkholderiales, Enterobacteriales and Azospirillales. A holobiont approach was applied as an integrated analytical strategy to resolve the coordinated and complex dynamic interactions between the plant and its rhizosphere bacteria using Arabidopsis thaliana as a model host species

High temperature indentation creep and nanoindentation testing of superalloys and TiAl alloys

Measuring of the high temperature mechanical behaviour of materials by local testing has become a key task in the field of nanomechanics. However, gaining access to the application temperature of many metallic high temperature materials, which is in the range of 600°C - 1100°C, is quite difficult. In addition, creep parameters can only be determined by long time measurements, where drift influences become a severe challenge. Here we present a new approach of indentation creep testing with a flat punch indenter. For this, a thermo mechanical analyzer with very precise temperature control is used, which allows testing at temperatures up to 1200°C. A flat punch indenter with a diameter of around 10 µm allows for example local investigations of the creep properties on the dendritic scale of superalloys. This approach is also interesting to study the creep properties along the gradient of diffusion couples. Here, first test measurements on superalloys and other materials are presented and discussed. For comparison also high temperature nanoindentation measurements will be shown. Such measurements have been conducted on a multiphase titanium aluminide alloy from room temperature up to 600°C. The results show, that the hardness of the (β0+ω0)-composite phase is the highest among all phases and remains constant up to the service temperature. Both approaches of high temperature testing are compared and the prospect of these methods will be discussed