NH concentrations below the current critical level affect the epiphytic macrolichen communities - Evidence from a Northern European City.

Acidophytic, oligotrophic lichens on tree trunks are widely considered to be the most sensitive biota to elevated concentrations of atmospheric ammonia (NH). We studied the relationships between measured NH concentrations and the composition of macrolichen communities on the acidic bark of Pinus sylvestris and Quercus robur and the base-rich bark of Acer platanoides and Ulmus glabra at ten roadside and ten non-roadside sites in Helsinki, Finland. NH and nitrogen dioxide (NO) concentrations were higher at the roadside than non-roadside sites indicating traffic as the main source of NH and nitrogen oxides (NO).

4D-Var Inversion of European NH Emissions Using CrIS NH Measurements and GEOS-Chem Adjoint With Bi-Directional and Uni-Directional Flux Schemes.

We conduct the first 4D-Var inversion of NH accounting for NH bi-directional flux, using CrIS satellite NH observations over Europe in 2016. We find posterior NH emissions peak more in springtime than prior emissions at continental to national scales, and annually they are generally smaller than the prior emissions over central Europe, but larger over most of the rest of Europe. Annual posterior anthropogenic NH emissions for 25 European Union members (EU25) are 25% higher than the prior emissions and very close (<2% difference) to other inventories.

Alkaline air: changing perspectives on nitrogen and air pollution in an ammonia-rich world.

Ammonia and ammonium have received less attention than other forms of air pollution, with limited progress in controlling emissions at UK, European and global scales. By contrast, these compounds have been of significant past interest to science and society, the recollection of which can inform future strategies. Sal ammoniac (, ) is found to have been extremely valuable in long-distance trade ( AD 600-1150) from Egypt and China, where 6-8 kg N could purchase a human life, while air pollution associated with collection was attributed to this nitrogen form.

Prospective Evaluation of Molecular Assays for Diagnosis of Vaginitis.

Molecular tests to diagnose conditions involving the disruption of normal microbiota are difficult to optimize. Using Nugent-scored Gram stain (NS) as the reference standard, we evaluated the performance of 3 molecular assays for the diagnosis of bacterial vaginosis (BV) and examined the impact of an incremental increase in bacterial targets. The BD Affirm assay includes a DNA probe for , the Hologic transcription-mediated amplification (TMA) analyte-specific reagent (ASR) assay adds a second sp.