Inverse Methods: a Powerful Tool for Evaluating Aerosol Data, Exemplified on Cases With Relevance for the Atmosphere and the Aerosol Climate Effect

For a complete description of a given aerosol, more than one parameter is necessary, e.g. parameters concerning size distribution, chemical composition, and particle morphology. On the other hand, most instruments measuring aerosol properties are sensitive mostly to one parameter, but cross-sensitive to others. These cross-sensitivities are often eliminated by assumptions during data evaluation, inducing systematic uncertainties in the results. The use of assumptions can be reduced by combining the information of several instruments on the same aerosol and using inverse methods for interpretation of the data. The presentation focuses on two application examples of these methods. The first example concerns a size distribution inversion algorithm that combines data from several instruments into one size distribution. The second example deals with an algorithm that retrieves the aerosol asymmetry parameter (with respect to particle scattering) from measurements of the aerosol absorption and spectral scattering and hemispheric backscattering coefficients, thereby providing a set of parameters that completely describes an aerosol with respect to its direct climate effect

Qualitative and Quantitative Detection of Botulinum Neurotoxins from Complex Matrices: Results of the First International Proficiency Test

In the framework of the EU project EQuATox a first international proficiency test (PT) on the detection and quantification of BoNT was conducted. Sample materials included BoNT serotypes A, B and E spiked into buffer, milk, meat extract and serum. A variety of methods was applied by the participants combining different principles of detection, identification and quantification. Based on qualitative assays, 95% of all results reported were correct. Successful strategies for BoNT detection were based on a combination of complementary immunological, MS-based and functional methods or on suitable functional in vivo / in vitro approaches (mouse bioassay, hemidiaphrama assay, Endopep-MS assay). Quantification of BoNT/A, BoNT/B and BoNT/E was performed by 48% of participating laboratories. It turned out that precise quantification of BoNT was difficult resulting in a substantial scatter of quantitative data. This was especially true for results obtained by the mouse bioassay which is currently seen as “gold standard” for BoNT detection. The results clearly demonstrate the urgent need of certified BoNT reference materials and the development of methods replacing animal testing. In this context, the BoNT PT provided the valuable information that both the Endopep-MS assay and the hemidiaphrama assay delivered quantitative results superior to the mouse bioassay.JRC.D.2-Standards for Innovation and sustainable Developmen

Miocene (23–13 Ma) continental paleotemperature record from the northern Mediterranean region (Digne-Valensole Basin, SE France) within a global climatic framework

During the Middle Miocene, the Earth’s climate transitioned from a warm phase, the Miocene Climatic Optimum (MCO, 16.9–14.7 Ma), to a colder phase associated by formation of major ice sheets on Antarctica. This climatic shift, the Middle Miocene Climatic Transition (MMCT, 14.7–13.8 Ma), considerably impacted not only the structure and formation of major ecosystems (e.g. Jimenez-Moreno & Suc, 2005) it also affected global ocean circulation (Holbourn et al., 2014), terrestrial temperatures as well as precipitation patterns (e.g. Methner et al., 2020). While the MCO and the subsequent MMCT are well described in marine records, knowledge about the magnitude and rate of terrestrial paleoclimate changes is often limited by lack of temporal resolution and reliable quantitative proxy records (Steinthorsdottir et al., 2021). Here, we present a long-term (23–13 Ma) biostratigraphically-controlled terrestrial stable (δ18O, δ13C) and clumped (Δ47) isotope paleosol carbonate record from the northern Mediterranean region (Digne-Valensole basin, SE France). When comparing the northern Mediterranean δ18O, δ13C and Δ47 record with age-equivalent counterparts from central Europe (Northern Alpine Foreland Basin, Switzerland), our Δ47 results from the Digne-Valensole basin reveal two important features: 1) Relatively warm and constant carbonate formation temperatures (ca. 30°C) for the Early Miocene (23–18.6 Ma) followed by 2) intensified temperature fluctuations with high values (ca. 37°C) at the onset of the MCO, most probably amplified by changes in seasonality of pedogenic carbonate formation. The combined Northern Alpine foreland and northern Mediterranean records display a coherent climate pattern for the Middle Miocene circum-Alpine foreland. In both records, high-amplitude, rapid changes in Δ47 temperatures (ca. 18°C within 400 ka) characterize the onset of the MCO and MMCT. We furthermore identify warm peaks during the MCO and a distinct fall in apparent Δ47-based temperatures at ca. 14 Ma that is in very good temporal agreement with oceanic isotope records and coincides with the documented global cooling following the MCT. Collectively, these data contribute to understanding of the dynamics and variability in atmospheric circulation controlling Middle to Late Miocene temperature dynamics in the Northern Mediterranean region

Desert Dust Air Mass Mapping in the Western Sahara, using Particle Properties Derived from Space-based Multi-angle Imaging

Coincident observations made over the Moroccan desert during the SAhara Mineral dUst experiMent (SAMUM) 2006 field campaign are used both to validate aerosol amount and type retrieved from Multi-angle Imaging SpectroRadiometer (MISR) observations, and to place the sub-orbital aerosol measurements into the satellite's larger regional context. On three moderately dusty days for which coincident observations were made, MISR mid-visible aerosol optical thickness (AOT) agrees with field measurements point-by-point to within 0.05 to 0.1. This is about as well as can be expected given spatial sampling differences; the space-based observations capture AOT trends and variability over an extended region. The field data also validate MISR's ability to distinguish and to map aerosol air masses, from the combination of retrieved constraints on particle size, shape, and single-scattering albedo. For the three study days, the satellite observations (a) highlight regional gradients in the mix of dust and background spherical particles, (b) identify a dust plume most likely part of a density flow, and (c) show an air mass containing a higher proportion of small, spherical particles than the surroundings, that appears to be aerosol pollution transported from several thousand kilometers away

Peripheral signaling pathways contributing to non-histaminergic itch in humans

BACKGROUND: Chronic itch (chronic pruritus) is a major therapeutic challenge that remains poorly understood despite the extensive recent analysis of human pruriceptors. It is unclear how the peripheral nervous system differentiates the signaling of non-histaminergic itch and pain. METHODS: Here we used psychophysical analysis and microneurography (single nerve fiber recordings) in healthy human volunteers to explore the distinct signaling mechanisms of itch, using the pruritogens β-alanine, BAM 8-22 and cowhage extract. RESULTS: The mode of application (injection or focal application using inactivated cowhage spicules) influenced the itch/pain ratio in sensations induced by BAM 8-22 and cowhage but not β-alanine. We found that sensitizing pre-injections of prostaglandin E2 increased the pain component of BAM 8-22 but not the other pruritogens. A-fibers contributed only to itch induced by β-alanine. TRPV1 and TRPA1 were necessary for itch signaling induced by all three pruritogens. In single-fiber recordings, we found that BAM 8-22 and β-alanine injection activated nearly all CM-fibers (to different extents) but not CMi-fibers, whereas cowhage extract injection activated only 56% of CM-fibers but also 25% of CMi-fibers. A "slow bursting discharge pattern" was evoked in 25% of CM-fibers by β-alanine, in 35% by BAM 8-22, but in only 10% by cowhage extract. CONCLUSION: Our results indicate that no labeled line exists for these pruritogens in humans. A combination of different mechanisms, specific for each pruritogen, leads to itching sensations rather than pain. Notably, non-receptor-based mechanisms such as spatial contrast or discharge pattern coding seem to be important processes. These findings will facilitate the discovery of therapeutic targets for chronic pruritus, which are unlikely to be treated effectively by single receptor blockade

Genome-wide analysis of single nucleotide polymorphisms uncovers population structure in Northern Europe

Peer reviewe

Desert dust aerosol air mass mapping in the western Sahara, using particle properties derived from space-based multi-angle imaging

Coincident observations made over the Moroccan desert during the Sahara mineral dust experiment (SAMUM) 2006 field campaign are used both to validate aerosol amount and type retrieved from multi-angle imaging spectroradiometer (MISR) observations, and to place the suborbital aerosol measurements into the satellite’s larger regional context. On three moderately dusty days during which coincident observations were made, MISR mid-visible aerosol optical thickness (AOT) agrees with field measurements point-by-point to within 0.05–0.1. This is about as well as can be expected given spatial sampling differences; the space-based observations capture AOT trends and variability over an extended region. The field data also validate MISR’s ability to distinguish and to map aerosol air masses, from the combination of retrieved constraints on particle size, shape and single-scattering albedo. For the three study days, the satellite observations (1) highlight regional gradients in the mix of dust and background spherical particles, (2) identify a dust plume most likely part of a density flow and (3) show an aerosol air mass containing a higher proportion of small, spherical particles than the surroundings, that appears to be aerosol pollution transported from several thousand kilometres away