391 research outputs found

    Microbial CH4 and N2O Consumption in Acidic Wetlands

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    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 anoxicā€“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

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    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 800Ā°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

    Citizen science in smart cities

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    Space-time evolution of bulk QCD matter

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    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

    Pressefƶrderung als Mittel gegen Medienkonzentration und fĆ¼r die publizistische Vielfalt? Quasi-experimentelle Untersuchung der Schweiz im Vergleich zu Belgien, Ɩsterreich, Irland sowie Deutschland

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    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

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

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    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

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    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

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    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 600Ā°C - 1100Ā°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 1200Ā°C. A flat punch indenter with a diameter of around 10 Āµm 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 600Ā°C. The results show, that the hardness of the (Ī²0+Ļ‰0)-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

    Changes of Self-Rated Health Status, Overweight and Physical Activity During Childhood and Adolescenceā€”The Ratchet Effect of High Parental Socioeconomic Status

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    Childhood and adolescence are important life periods for the development of health status and physical activity (PA) behaviours. This study analyses the stability and potential changes of self-rated health status, overweight and PA behaviour over time, specifically focusing on the age and the socioeconomic status of children and adolescents. We employ representative longitudinal data for German children and adolescents from the Motorik-Modul Study and the German Health Interview and Examination Survey. Using four different dichotomous health status and PA indicators (self-rated health status [SRHS]; overweight; moderate-to-vigorous PA; and leisure sports engagement), we report within-person transition rates across the panel waves when the survey was taken (2003ā€“2006, 2009ā€“2012, and 2014ā€“2017). Additionally, we report results of logistic regressions estimating the impact of children\u27s age, gender, migration background, and their parents\u27 socioeconomic status on these transition rates. The transition rates show mixed results. While children and adolescents from highly problematic states reporting bad SRHS and no leisure sports engagement at an early stage tend to improve later on, overweight children mostly stay overweight. Age and social inequality indicators correlate with some of the chances of improving or worsening the health and PA states. Most clearly, high parental status prevents the health status and PA from worsening over all transitions, particularly becoming overweight, representing a ratchet effect. The results of the present study underline that health policy needs to target specific groups to reduce social inequality in the health status and PA of children and adolescents

    Physical Activity and Recurrent Pain in Children and Adolescents in Germanyā€”Results from the MoMo Study

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    Recurrent pain can be a significant disruption in the activities of daily life, and is not only a health problem in adults but also in children and adolescents. This study analyzed the prevalence of recurrent pain in the current sample (n = 1516; 11ā€“17 years (meanage_{age} = 14.4 Ā± 2.0 years); 50.8% female) of a nationwide study in Germany, evaluated the association of participantsā€™ device-based physical activity (PA) with the prevalence of recurrent pain, and assessed whether children and adolescents who reported pain for the last three months accumulated less PA than those who did not. A higher prevalence was found in girls for recurrent headaches (42.2% vs. 28.7%), abdominal pain (28.2% vs. 20.1%), and back pain (26.9% vs. 19.5%). We found higher odds for recurrent headaches in girls (OR = 1.54) and in participants that did not reach at least 60 min of moderate to vigorous PA (MVPA) per day (OR = 2.06). Girls who reported recurrent headaches accumulated 4.7 min less MVPA per day than those without. The prevalence of pain remains at a high level in the German youth and underscores the need for interventions to improve the health situations of children and adolescents
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