Quantifying nitrogen fluxes and their influence on the greenhouse gas balance: recent findings of the NitroEurope Integrated Project

The generation of reactive nitrogen (Nr) by human activities to stimulate agricultural productivity and the unintended formation of Nr in combustion processes both have major impacts on the global environment. Effects of excess Nr include the deterioration of air quality, water quality, soil quality and a decline in biodiversity. One of the most controversial impacts of nitrogen, however, is on the greenhouse gas balance. While recent papers have highlighted a possible benefit of nitrogen in enhancing rates of carbon sequestration, there remain many trade-offs between nitrogen and greenhouse gas exchange. The result is that the net effect of Nr on the global radiative balance has yet to be fully quantified. To better understand these relationships requires intense measurement and modelling of Nr fluxes at various temporal and spatial scales in order to make the link between different nitrogen forms and their fate in the environment. It is essential to measure fluxes for a wide range of ecosystems considering the biosphere-atmosphere exchange of the Nr components and greenhouse gases, as well as the fixation of di-nitrogen and its creation by denitrification. Long-term observations are needed for representative ecosystems, together with results from experiments addressing the responses of the key nitrogen and greenhouse gas fluxes to different global change drivers. The NitroEurope Integrated Project (in short NEU IP), funded under the 6th Framework Programme of the European Commission, has developed and applied a strategy for quantifying these different terms on multiple scales. With the project nearing completion, this presentation reports selected preliminary findings. It highlights the first estimates of Nr inputs and net green-house gas exchange for a series of 13 flux ‘supersites’, complemented by the emerging results of Nr concentrations and related N inputs at a network of 58 ‘inferential sites’, which extend the European representativity of the results. In addition, new low cost methods to measure nitrogen fluxes will be reported, which have been extensively tested at those sites. Results from this 3-tier flux network are underpinned by emerging findings from an extensive network of manipulation sites. A combination of modelling at plot, landscape and European scales is used to upscale the results. Finally the talk will illustrate how nitrogen mitigation techniques are being considered at the European scale, including an estimation of the scale of costs involved in simultaneously mitigating nitrous oxide, ammonia and nitrate losse

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

The Assessment and Evaluation of Arctic Research – Where Have We Come From and Where Do We Need to Go in the Future?

This essay represents the penultimate chapter of a volume that focuses on change in the Arctic and the challenges and opportunities for conducting research within the context of NordForsk’s Responsible Development of the Arctic initiative. It provides both a backward glance at the needs that inspired this undertaking and seeks to offer some forward-looking ideas and suggestions as to the direction for future similarly-directed research efforts within the North. It gives attention to the important roles which assessment and evaluation have played in the evolution of the NordForsk project and focuses attention on the specific work of the Scientific Advisory Board (SAB) within this context. It discusses some of the challenges the SAB has encountered in conducting its work. Comparisons are also made with similar efforts at assessment and evaluation conducted by other funders of Arctic research. Views are also presented in this essay on the nature of integrated assessment within large and complex undertakings like the Responsible Development of the Arctic. Finally, a discussion is offered concerning where the future of interdisciplinary and cross-disciplinary scientific research in the Arctic may be headed and the requirements it must embrace in order to be successful

Markov Chain Monte Carlo simulation and regression approach guided by El Niño–Southern Oscillation to model the tropical cyclone occurrence over the Bay of Bengal

Tropical cyclone (TC) is one of the most devastating weather systems that causes enormous loss of life and property in the coastal regions of Bay of Bengal (BoB). Statistical forecasting of TC occurrence can help decision-makers and inhabitants in shoreline zones to take necessary planning and actions in advance. In this study, we have investigated the impact of El Niño–Southern Oscillation (ENSO) on the frequency of TC over the BoB by using 100 years TC and Southern Oscillation Index data. The frequency of TC is approximated through observation and Markov Chain Monte Carlo (MCMC) simulation. Two-sample Student’s t test has been applied for examining the statistical significance where the results are significant at 5% level for all cyclonic disturbances. The monthly and seasonal distribution show this feature more distinctly. The total annual frequency of depressions and cyclonic storms in El Niño and La Niña conditions does not differ much, but the monthly/seasonal distribution shows high differences for certain months and seasons. The simulated frequency of TC landfall using MCMC matches well with the observation. The proposed methodology is illustrated through a case study in BoB rim countries-Bangladesh, India, Sri Lanka and Myanmar. Poisson and Bayesian regression have also been used to predict the probabilities of TC frequency over the BoB. Both the regression approaches show 10 and 32% improvement than climatology for the forecast and cross-validation skill respectively. We have also analyzed TC impact over Bangladesh as a case study. Possible links of the variation of TC activities with the largescale geographical distribution of sea surface temperature, vertical wind shear, vorticity, moisture and relative humidity are also explored.</p

Mechanism of Action of a Nanomolar Potent, Allosteric Antagonist of the Thyroid-Stimulating Hormone Receptor

Background and purpose  Graves' disease (GD) is an autoimmune disease in which the thyroid is overactive, producing excessive amounts of thyroid hormones, caused by TSHR-stimulating immunoglobulins (TSIs). A large proportion of GD patients also suffer from thyroid eye disease (Graves' ophthalmopathy or GO), with the TSIs considered to activate TSHRs in orbital tissue also. We recently developed LMW TSHR antagonists as a novel therapeutic strategy for the treatment of GD and GO. In the present study, we determined the molecular pharmacology of a prototypic, nanomolar potent LMW TSHR antagonist, Org 274179-0. Experimental approach  First, we determined the potency and efficacy of Org 274179-0 in antagonizing TSH- and TSI-induced TSHR signaling and its cross-reactivity at the related FSHR and LHR. Second, we explored in depth the allosteric mode of interaction of Org 274179-0. Third, we determined whether Org 274179-0 is an inverse agonist at five naturally occurring, constitutively active TSHR mutants. Key results  Org 274179-0 fully inhibited TSH (and TSI)-mediated TSHR activation with nanomolar potency without hardly affecting the potency of TSH, in accordance with an allosteric mechanism of action. On the reverse, increasing levels of TSHR stimulation only marginally reduced the antagonistic potency of Org 274179-0. Finally, Org 274179-0 fully blocked the increased basal activity of all tested constitutively active TSHR mutants with nanomolar potencies. Conclusions and implications  We conclude that nanomolar potent TSHR antagonists like Org 274179-0 have the potential of being developed to treat GD and GO