Helmholtz Centre for Environmental Research - UFZ

About: Helmholtz Centre for Environmental Research - UFZ is a facility organization based out in Leipzig, Germany. It is known for research contribution in the topics: Population & Species richness. The organization has 3230 authors who have published 9880 publications receiving 394385 citations.

glUV: a global UV‐B radiation data set for macroecological studies

Abstract: 1. Macroecology has prospered in recent years due in part to the wide array of climatic data, such as those provided by theWorldClim and CliMond data sets, which has become available for research. However, important environmental variables have still been missing, including spatial data sets on UV-B radiation, an increasingly recognized driver of ecological processes. 2. We developed a set of globalUV-B surfaces (glUV) suitable to match common spatial scales in macroecology. Our data set is based on remotely sensed records fromNASA’sOzone Monitoring Instrument (Aura-OMI). Following a similar approach as for theWorldClim and CliMond data sets, we processed daily UV-B measurements acquired over a period of eight years into monthly mean UV-B data and six ecologically meaningful UV-B variables with a 15-arc minute resolution. These bioclimatic variables represent Annual Mean UV-B, UV-B Seasonality, Mean UV-B of Highest Month, Mean UV-B of Lowest Month, Sum of Monthly Mean UV-B during Highest Quarter and Sum of Monthly Mean UV-B during Lowest Quarter. We correlated our data sets with selected variables of existing bioclimatic surfaces for land and with Terra–MODIS Sea Surface Temperature for ocean regions to test for relations to known gradients and patterns. 3. UV-B surfaces showed a distinct seasonal variance at a global scale, while the intensity of UV-B radiation decreased towards higher latitudes and was modified by topographic and climatic heterogeneity. UV-B surfaces were correlated with global mean temperature and annual mean radiation data, but exhibited variable spatial associations across the globe.UV-B surfaces were otherwise widely independent of existing bioclimatic surfaces. 4. Our data set provides new climatological information relevant for macroecological analyses. As UV-B is a known driver of numerous biological patterns and processes, our data set offers the potential to generate a better understanding of these dynamics inmacroecology, biogeography, global change research and beyond. The glUV data set containing monthly mean UV-B data and six derived UV-B surfaces is freely available for download at: http://www.ufz.de/gluv.

Maternal and cord blood miR-223 expression associates with prenatal tobacco smoke exposure and low regulatory T-cell numbers

Abstract: Background There is evidence that microRNAs (miRNAs) are sensitive to environmental stressors, including tobacco smoke. On the other hand, miRNAs are involved in immune regulation, such as regulatory T (Treg) cell differentiation. The aim of the present study was to investigate the association between prenatal tobacco smoke exposure, miRNAs, and Treg cell numbers. Methods Within a prospective mother-child study (Lifestyle and Environmental Factors and Their Influence on Newborns Allergy Risk), we analyzed the expression of miR-155 and miR-223 together with Treg cell numbers in maternal blood during pregnancy, as well as in cord blood (n = 441). Tobacco smoke exposure was assessed based on questionnaire answers and maternal urine cotinine levels. Additionally, the concentration of smoking-related volatile organic compounds was measured in dwellings of study participants. Results Both maternal and cord blood miR-223 expressions were positively correlated with maternal urine cotinine levels. An association was also found between maternal miR-223 expression and indoor concentrations of benzene and toluene. High miR-223 expression was associated with lower Treg cell numbers in maternal and cord blood. Furthermore, children with lower Treg cell numbers at birth had a higher risk of atopic dermatitis during the first 3 years of life. The concentration of the toluene metabolite S-benzylmercapturic acid in maternal urine was associated with decreased cord blood, but not maternal blood, miR-155 expression. A relationship between miR-155 expression and Treg cell numbers was not found. Conclusions For the first time, we show that maternal tobacco smoke exposure during pregnancy correlates with the level of miRNA-223 expression in blood, with an effect on children's cord blood Treg cell numbers and subsequent allergy risk.

Quantification of N2O emission pathways via a 15N tracing model

Abstract: A 15N tracing model was developed to analyse nitrous oxide (N2O) dynamics in terrestrial ecosystems, which build on previous tracing models for the quantification of the main mineral nitrogen (N) transformations and soil nitrite (NO2 -) dynamics. The N2O dynamics in the model are directly associated with three NO2 - sub-pools. Four pathways for N2O production in soil were considered in the model: i) reduction of NO2 - associated with nitrification (NO2 - nit ? N2Onit), ii) reduction of NO2 - associated with denitrification (NO2 - den ? N2Oden), iii) reduction of NO2 - associated with organic N (Norg) oxidation (NO2 - org ? N2Oorg), and iv) codenitrification (N2Ocod), a hybrid reaction where one N atom in N2O originates from organic N and the other from NO2 - den. Soil N2O can further be reduced to N2 and/or can be emitted to the atmosphere. The reaction kinetics and emission notations are based on first-order approaches. Parameter optimization was carried out with a Markov Chain Monte Carlo (MCMC) technique that is suitable for models with large number of parameters. The 15N tracing tool was tested with a data set from a 15N tracing study on grassland soil. Tracing model results showed that on average over a 12 day period N2Onit, N2Oden, N2Oorg and N2Ocod contributed 9%, 20%, 54% and 18% to the total N2O emission, respectively. The results are in line with estimates based on analytical approaches that consider three N2O emission pathways. The strength of this new 15N tracing tool is that for the first time four N2O emission pathways, including a hybrid-reaction, can simultaneously be quantified. The analysis highlights that heterotrophic processes related to organic N turnover and neither autotrophic nitrification nor denitrification may be the prevailing pathways for N2O production in old grassland soil. The underlying NO2 - and N2O reduction kinetics are in agreement with denitrification gene expressions and the calculated N2/N2O ratios are in the expected range. The tracing model provides insights on N dynamics which may occur in soil microsites. This information is important for the development of more realistic representations of soil N cycling in ecosystem models. © 2014 Elsevier Ltd. (Less)

Multiscale scenarios for nature futures

Abstract: Targets for human development are increasingly connected with targets for nature, however, existing scenarios do not explicitly address this relationship. Here, we outline a strategy to generate scenarios centred on our relationship with nature to inform decision-making at multiple scales.