How does the local wind field control the aerosol distribution in coastal Dronning Maud Land?

Atmospheric circulation patterns and chemical concentrations in firn cores are highly related to each other. Atmospheric winds transport aerosols like sea salt and mineral dust over the globe and redistribute them. Because of this, it is possible to reconstruct atmospheric circulation bringing aerosol to Antarctica by analyzing chemical impurities in firn and ice. With these analyses, the gap caused by sparse atmospheric measurements can be filled and this knowledge can then be used to improve the understanding of local and global circulation patterns.Due to a very high accumulation rate (~600 kg/m²*a), coastal Dronning Maud Land (CDML) is a perfect site to conduct these studies.Here, the upper 6m of two firn cores drilled on Halvfaryggen and Sörasen (covering the time interval from 2002- 2007) were analyzed on ionic concentrations. This data was then contrasted to measurements from the air chemistry laboratories at Neumayer (NM) and Kohnenstation (KS), and synoptic measurements from automatic weather stations (distributed in CDML and at NM).The analyses show very different results: Sea salt ions (e.g. Na+) are higher correlated to ions measured in aerosol samples at the air chemistry laboratory at KS than to the one located at NM. In contrast, ions representing mineral dust (e.g. nss-Ca2+) only have a weak correlation over the whole area and time period. Accordingly, the deposition of aerosol is highly dependent on its origin and the topography in coastal Antarctica suggesting different transport pathways for sea level and higher altitude sites

Carvacrol ameliorates acute campylobacteriosis in a clinical murine infection model

Background: The prevalence of human infections with the zoonotic pathogen Campylobacter jejuni is rising worldwide. Therefore, the identification of compounds with potent anti-pathogenic and anti-inflammatory properties for future therapeutic and/or preventive application to combat campylobacteriosis is of importance for global health. Results of recent studies suggested carvacrol (4-isopropyl-2-methylphenol) as potential candidate molecule for the treatment of campylobacteriosis in humans and for the prevention of Campylobacter colonization in farm animals. Results: To address this in a clinical murine infection model of acute campylobacteriosis, secondary abiotic IL-10-/- mice were subjected to synthetic carvacrol via the drinking water starting 4 days before peroral C. jejuni challenge. Whereas at day 6 post-infection placebo treated mice suffered from acute enterocolitis, mice from the carvacrol cohort not only harbored two log orders of magnitude lower pathogen loads in their intestines, but also displayed significantly reduced disease symptoms. Alleviated campylobacteriosis following carvacrol application was accompanied by less distinct intestinal apoptosis and pro-inflammatory immune responses as well as by higher numbers of proliferating colonic epithelial cells. Remarkably, the inflammation-ameliorating effects of carvacrol treatment were not restricted to the intestinal tract, but could also be observed in extra-intestinal organs such as liver, kidneys and lungs and, strikingly, systemically as indicated by lower IFN-γ, TNF, MCP-1 and IL-6 serum concentrations in carvacrol versus placebo treated mice. Furthermore, carvacrol treatment was associated with less frequent translocation of viable C. jejuni originating from the intestines to extra-intestinal compartments. Conclusion: The lowered C. jejuni loads and alleviated symptoms observed in the here applied clinical murine model for human campylobacteriosis highlight the application of carvacrol as a promising novel option for both, the treatment of campylobacteriosis and hence, for prevention of post-infectious sequelae in humans, and for the reduction of C. jejuni colonization in the intestines of vertebrate lifestock animals

Immunopathological properties of the Campylobacter jejuni flagellins and the adhesin CadF as assessed in a clinical murine infection model

Background: Campylobacter jejuni infections constitute serious threats to human health with increasing prevalences worldwide. Our knowledge regarding the molecular mechanisms underlying host-pathogen interactions is still limited. Our group has established a clinical C. jejuni infection model based on abiotic IL-10-/- mice mimicking key features of human campylobacteriosis. In order to further validate this model for unraveling pathogen-host interactions mounting in acute disease, we here surveyed the immunopathological features of the important C. jejuni virulence factors FlaA and FlaB and the major adhesin CadF (Campylobacter adhesin to fibronectin), which play a role in bacterial motility, protein secretion and adhesion, respectively. Methods and results: Therefore, abiotic IL-10-/- mice were perorally infected with C. jejuni strain 81-176 (WT) or with its isogenic flaA/B (ΔflaA/B) or cadF (ΔcadF) deletion mutants. Cultural analyses revealed that WT and ΔcadF but not ΔflaA/B bacteria stably colonized the stomach, duodenum and ileum, whereas all three strains were present in the colon at comparably high loads on day 6 post-infection. Remarkably, despite high colonic colonization densities, murine infection with the ΔflaA/B strain did not result in overt campylobacteriosis, whereas mice infected with ΔcadF or WT were suffering from acute enterocolitis at day 6 post-infection. These symptoms coincided with pronounced pro-inflammatory immune responses, not only in the intestinal tract, but also in other organs such as the liver and kidneys and were accompanied with systemic inflammatory responses as indicated by increased serum MCP-1 concentrations following C. jejuni ΔcadF or WT, but not ΔflaA/B strain infection. Conclusion: For the first time, our observations revealed that the C. jejuni flagellins A/B, but not adhesion mediated by CadF, are essential for inducing murine campylobacteriosis. Furthermore, the secondary abiotic IL-10-/- infection model has been proven suitable not only for detailed investigations of immunological aspects of campylobacteriosis, but also for differential analyses of the roles of distinct C. jejuni virulence factors in induction and progression of disease

Low levels of nestmate discrimination despite high genetic differentiation in the invasive pharaoh ant

<p>Abstract</p> <p>Background</p> <p>Ants typically distinguish nestmates from non-nestmates based on the perception of colony-specific chemicals, particularly cuticular hydrocarbons present on the surface of the ants' exoskeleton. These recognition cues are believed to play an important role in the formation of vast so-called supercolonies that have been described for some invasive ant species, but general conclusions about the role of these cues are hampered by only few species being studied. Here we use data on cuticular hydrocarbons, aggression and microsatellite genetic markers to investigate the interdependence of chemical recognition cues, genetic distance and nestmate discrimination in the pharaoh ant (<it>Monomorium pharaonis</it>), a widespread pest species, and ask whether introduced populations of this species are genetically differentiated and exhibit intraspecific aggression.</p> <p>Results</p> <p>Microsatellite analyses of a total of 35 colonies from four continents revealed extremely high levels of genetic differentiation between almost all colonies (<it>F</it>_ST= 0.751 ± 0.006 SE) and very low within-colony diversity. This implies that at least 34 and likely hundreds more independent lineages of this ant have spread worldwide. Aggression tests involving workers from 14 different colonies showed only low levels of aggression, even between colonies that were geographically and/or genetically very distant. Chemical analyses of groups of worker ants showed that all colonies had the same cuticular compounds, which varied only quantitatively among colonies. There was a positive correlation between geographical and genetic distance, but no other significant relationships were detected between aggression, chemical profile, genetic distance and geographical distance.</p> <p>Conclusions</p> <p>The pharaoh ant has a global invasion history of numerous independent introductions resulting in genetically highly differentiated colonies typically displaying surprisingly low levels of intraspecific aggression, a behaviour that may have evolved in the native range or by lineage selection in the introduced range.</p

Mapping Transitions in the Life Course: An Exploration of Process Ontological Potentials and Limits of Situational Analysis

In our article we focus on potentials and challenges that arise in the use of situational analysis for reflexive-relational transition research. We discuss how transitions can be mapped as transformation processes in the life course and mapping can function as reflective tool in research projects. We explore mapping transitions not only as static situations, but also in their complex processuality. To do this, we discuss transition and reflexive maps inspired by CLARKE's situational analysis, and thereby the challenge of mapping processes. We start by discussing a mapping strategy inspired by situational analysis for the study of transitions, and proceed with an innovation of maps based on a research project. The aim is to trace the processes of change and to be able to analyze and map the connections between different dimensions and actors in these events. We reflect on various mapping strategies developed in the project to analyze spatial-material and temporal-processual aspects, their potentials, and limitations as well as the research process. Mapping processes remains challenging and important for future research. Combining situational analysis and life course research opens up possibilities for researchers to better conceptualize the processuality of situations and to test different mapping procedures for this purpose. We start by discussing a mapping strategy inspired by situational analysis for the study of transitions, and proceed with an innovation of maps based on a research project. The aim is to trace the processes of change and to be able to analyze and map the connections between different dimensions and actors in these events. We reflect on various mapping strategies developed in the project to analyze spatial-material and temporal-processual aspects, their potentials, and limitations as well as the research process. Mapping processuality remains challenging and important for future research. Combining situational analysis and life course research opens up possibilities for researchers to better conceptualize the processuality of situations and to test different mapping procedures for this purpose.In dem Artikel fokussieren wir Potenziale und Herausforderungen, die sich bei der Nutzung der Situationsanalyse für die reflexiv-relationale Übergangs- und Lebenslaufforschung ergeben. Es wird erörtert, wie Übergänge als Transformationsprozesse im Lebenslauf visualisiert werden können und wie Mapping als Reflexionsinstrument eingesetzt werden kann. Wir verstehen Übergänge als prozesshafte Gebilde, in denen Transformation verhandelt wird und untersuchen, wie diese mithilfe der Situationsanalyse nicht nur als statische Situationen, sondern auch in ihrer komplexen Prozesshaftigkeit abgebildet werden können. Wir diskutieren Übergangs- und Reflexions-Maps, die von CLARKEs Situationsanalyse angeregt sind und damit die Herausforderung, Prozesshaftigkeit darzustellen. Nach der Diskussion einer situationsanalytisch inspirierten Mapping-Strategie für die Untersuchung von Übergängen im Lebensverlauf stellen wir eine mögliche Innovation von Maps anhand eines Projekts vor. Mit diesem Ansatz wollen wir Veränderungsprozesse nachzeichnen und die Verbindungen zwischen verschiedenen Dimensionen und Akteur*innen in diesen Ereignissen analysieren und mappen. Wir reflektieren verschiedene Mapping-Strategien, die im Projektkontext entwickelt wurden, um räumlich-materielle und zeitlich-prozessuale Aspekte, ihre Potenziale und Grenzen sowie den Forschungsprozess zu untersuchen. Zusammenfassend bleibt das Mapping von Prozessualität eine Herausforderung und ein wichtiges Feld für zukünftige Forschung. Situationsanalyse und Lebenslaufforschung zusammenzudenken eröffnet Forschenden Möglichkeiten, die Prozessualität von Situationen konzeptionell besser zu fassen und hierfür verschiedene Mapping-Verfahren zu erproben. Nach der Diskussion einer situationsanalytisch inspirierten Mapping-Strategie für die Untersuchung von Übergängen im Lebensverlauf stellen wir eine mögliche Innovation von Maps anhand eines Projekts vor. Mit diesem Ansatz wollen wir Veränderungsprozesse nachzeichnen und die Verbindungen zwischen verschiedenen Dimensionen und Akteur*innen in diesen Ereignissen analysieren und mappen. Wir reflektieren verschiedene Mapping-Strategien, die im Projektkontext entwickelt wurden, um räumlich-materielle und zeitlich-prozessuale Aspekte, ihre Potenziale und Grenzen sowie den Forschungsprozess zu untersuchen. Zusammenfassend bleibt das Mapping von Prozessualität eine Herausforderung und ein wichtiges Feld für zukünftige Forschung. Situationsanalyse und Lebenslaufforschung zusammenzudenken eröffnet Forschenden Möglichkeiten, die Prozessualität von Situationen konzeptionell besser zu fassen und hierfür verschiedene Mapping-Verfahren zu erproben

Association between eczema and major cardiovascular outcomes in population-based studies: a systematic review protocol.

INTRODUCTION: Chronic inflammatory diseases such as eczema (also known as atopic dermatitis) have been inconsistently linked to cardiovascular disease and stroke in both mechanistic and epidemiological studies. There is a need to review the existing epidemiological data examining the association between eczema and major cardiovascular outcomes, including angina, myocardial infarction, coronary revascularisation, heart failure, cardiac arrhythmias, stroke and cardiovascular death, in order to improve our understanding of the comorbidities of eczema. METHODS AND ANALYSIS: We will systematically review population-based studies, including cohort, case-control and cross-sectional studies, reporting on the association between eczema and cardiovascular outcomes. We will search Medline, Embase and Global Health, from their date of inception to April 2017, using a comprehensive search strategy formulated with the help of a librarian. Two reviewers will independently screen titles and abstracts in duplicate, followed by independent data extraction and quality assessment. We will group studies by the cardiovascular outcome under study and synthesise them narratively. If sufficient numbers of homogeneous studies are returned, we will perform meta-analyses to obtain pooled effect estimates. Preferred Reporting Items for Systematic Review and Meta-Analysis will be used to inform the reporting of this study. TRIAL REGISTRATION NUMBER: CRD42017060359

High-Resolution Spectroscopic Study of Extremely Metal-Poor Star Candidates from the SkyMapper Survey

The SkyMapper Southern Sky Survey is carrying out a search for the most metal-poor stars in the Galaxy. It identifies candidates by way of its unique filter set that allows for estimation of stellar atmospheric parameters. The set includes a narrow filter centered on the Ca II K 3933A line, enabling a robust estimate of stellar metallicity. Promising candidates are then confirmed with spectroscopy. We present the analysis of Magellan-MIKE high-resolution spectroscopy of 122 metal-poor stars found by SkyMapper in the first two years of commissioning observations. 41 stars have [Fe/H] <= -3.0. Nine have [Fe/H] <= -3.5, with three at [Fe/H] ~ -4. A 1D LTE abundance analysis of the elements Li, C, Na, Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Co, Ni, Zn, Sr, Ba and Eu shows these stars have [X/Fe] ratios typical of other halo stars. One star with low [X/Fe] [X/Fe values appears to be "Fe-enhanced," while another star has an extremely large [Sr/Ba] ratio: >2. Only one other star is known to have a comparable value. Seven stars are "CEMP-no" stars ([C/Fe] > 0.7, [Ba/Fe] < 0). 21 stars exhibit mild r-process element enhancements (0.3 <=[Eu/Fe] < 1.0), while four stars have [Eu/Fe] >= 1.0. These results demonstrate the ability to identify extremely metal-poor stars from SkyMapper photometry, pointing to increased sample sizes and a better characterization of the metal-poor tail of the halo metallicity distribution function in the future.Comment: Minor corrections to text, missing data added to Tables 3 and 4; updated to match published version. Complete tables included in sourc

Association between eczema and major cardiovascular outcomes in population-based studies: a systematic review protocol.

INTRODUCTION: Chronic inflammatory diseases such as eczema (also known as atopic dermatitis) have been inconsistently linked to cardiovascular disease and stroke in both mechanistic and epidemiological studies. There is a need to review the existing epidemiological data examining the association between eczema and major cardiovascular outcomes, including angina, myocardial infarction, coronary revascularisation, heart failure, cardiac arrhythmias, stroke and cardiovascular death, in order to improve our understanding of the comorbidities of eczema. METHODS AND ANALYSIS: We will systematically review population-based studies, including cohort, case-control and cross-sectional studies, reporting on the association between eczema and cardiovascular outcomes. We will search Medline, Embase and Global Health, from their date of inception to April 2017, using a comprehensive search strategy formulated with the help of a librarian. Two reviewers will independently screen titles and abstracts in duplicate, followed by independent data extraction and quality assessment. We will group studies by the cardiovascular outcome under study and synthesise them narratively. If sufficient numbers of homogeneous studies are returned, we will perform meta-analyses to obtain pooled effect estimates. Preferred Reporting Items for Systematic Review and Meta-Analysis will be used to inform the reporting of this study. TRIAL REGISTRATION NUMBER: CRD42017060359