343 research outputs found

    Stable climate and surface mass balance in Svalbard over 1979–2013 despite the Arctic warming

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    With the help of the regional climate model MAR (Modèle Atmosphérique Régional) forced by the ERA-Interim reanalysis (MARERA) and the MIROC5 (Model for Interdisciplinary Research on Climate) global model (MARMIROC5) from the CMIP5 (Coupled Model Intercomparison Project) database, we have modelled the climate and surface mass balance of Svalbard at a 10 km resolution over 1979–2013. The integrated total surface mass balance (SMB) over Svalbard modelled by MARERA is negative (−1.6 Gt yr−1) with a large interannual variability (7.1 Gt) but, unlike over Greenland, there has been no acceleration of the surface melt over the past 35 years because of the recent change in atmospheric circulation bringing northwesterly flows in summer over Svalbard, contrasting the recent observed Arctic warming. However, in 2013, the atmospheric circulation changed to a south–southwesterly flow over Svalbard causing record melt, SMB (−20.4 Gt yr−1) and summer temperature. MIROC5 is significantly colder than ERA-Interim over 1980–2005 but MARMIROC5 is able to improve the near-surface MIROC5 results by simulating not significant SMB differences with MARERA over 1980–2005. On the other hand, MIROC5 does not represent the recent atmospheric circulation shift in summer and induces in MARMIROC5 a significant trend of decreasing SMB (−0.6 Gt yr−2) over 1980–2005

    Influenza Vaccination Behaviour of Healthcare Workers in Switzerland: A Cross-Sectional Study

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    Objectives: As no data are available regarding the influenza vaccination status of Swiss healthcare workers (HCW) in the ambulatory setting, this study aims to investigate their influenza vaccination behaviours. Methods: We conducted an online survey using a four-item, semi-structured questionnaire to assess HCWs influenza vaccination coverage and behaviour. Associations between influenza vaccination status, age and language as well as recommendation behaviour and reasons for vaccination were assessed using descriptive statistics and logistic regression analyses. Results: Of the 1057 completed questionnaires, 425 (40.2%) HCW were vaccinated and 632 (59.8%) not. 78.1% of the physicians and 47.3% pharmacists were vaccinated, compared to only 29.1% of the nurses, 24.3% pharmacy technicians and 13.0% medical practice assistants (MPA). There was a significant association between influenza vaccination status and HCW profession, age, language and how often an influenza vaccination recommendation was made. Conclusion: Demographic factors seem to influence HCWs’ attitudes towards influenza vaccination, which in turn affects the prospect of them recommending the influenza vaccination. Diverse strategies might be necessary to encourage HCW to get vaccinated and hence, promote influenza vaccination

    Decreased skin colonization with Malassezia spp. and increased skin colonization with Candida spp. in patients with severe atopic dermatitis

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    Background: Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease in which patients are sensitized towards a plethora of allergens. The hosts fungal microbiota, the mycobiota, that is believed to be altered in patients suffering from AD acts as such an allergen. The correlation context of specific sensitization, changes in mycobiota and its impact on disease severity however remains poorly understood. Objectives: We aim to enhance the understanding of the specific sensitization towards the mycobiota in AD patients in relation to their fungal skin colonization. Methods: Sensitization pattern towards the Malassezia spp. and Candida albicans of 16 AD patients and 14 healthy controls (HC) were analyzed with the newly developed multiplex-assay ALEX2® and the established singleplex-assay ImmunoCAP®. We compared these findings with the fungal skin colonization analyzed by DNA sequencing of the internal transcribed spacer region 1 (ITS1). Results: Sensitization in general and towards Malassezia spp. and C. albicans is increased in AD patients compared to HC with a quantitative difference in severe AD when compared to mild to moderate AD. Further we saw an association between sensitization towards and skin colonization with Candida spp. yet a negative correlation between sensitization towards and skin colonization with Malassezia spp. Conclusion: We conclude that AD in general and severe AD in particular is associated with increased sensitization towards the hosts own mycobiota. There is positive correlation in Candida spp. skin colonization and negative in Malassezia spp. skin colonization when compared to AD, AD severity as well as to specific sensitization patterns

    The circadian clock regulates rhythmic erythropoietin expression in the murine kidney

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    Generation of circadian rhythms is cell-autonomous and relies on a transcription/translation feedback loop controlled by a family of circadian clock transcription factor activators including CLOCK, BMAL1 and repressors such as CRY1 and CRY2. The aim of the present study was to examine both the molecular mechanism and the hemopoietic implication of circadian erythropoietin expression. Mutant mice with homozygous deletion of the core circadian clock genes cryptochromes 1 and 2 (Cry-null) were used to elucidate circadian erythropoietin regulation. Wild-type control mice exhibited a significant difference in kidney erythropoietin mRNA expression between circadian times 06 and 18. In parallel, a significantly higher number of erythropoietin-producing cells in the kidney (by RNAscope®) and significantly higher levels of circulating erythropoietin protein (by ELISA) were detected at circadian time 18. Such changes were abolished in Cry-null mice and were independent from oxygen tension, oxygen saturation, or expression of hypoxia-inducible factor 2 alpha, indicating that circadian erythropoietin expression is transcriptionally regulated by CRY1 and CRY2. Reporter gene assays showed that the CLOCK/BMAL1 heterodimer activated an E-box element in the 5' erythropoietin promoter. RNAscope® in situ hybridization confirmed the presence of Bmal1 in erythropoietin-producing cells of the kidney. In Cry-null mice, a significantly reduced number of reticulocytes was found while erythrocyte numbers and hematocrit were unchanged. Thus, circadian erythropoietin regulation in the normoxic adult murine kidney is transcriptionally controlled by master circadian activators CLOCK/BMAL1, and repressors CRY1/CRY2. These findings may have implications for kidney physiology and disease, laboratory diagnostics, and anemia therapy

    Greater Greenland Ice Sheet contribution to global sea level rise in CMIP6

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    Future climate projections show a marked increase in Greenland Ice Sheet (GrIS) runoff during the 21st century, a direct consequence of the Polar Amplification signal. Regional climate models (RCMs) are a widely used tool to downscale ensembles of projections from global climate models (GCMs) to assess the impact of global warming on GrIS melt and sea level rise contribution. Initial results of the CMIP6 GCM model intercomparison project have revealed a greater 21st century temperature rise than in CMIP5 models. However, so far very little is known about the subsequent impacts on the future GrIS surface melt and therefore sea level rise contribution. Here, we show that the total GrIS sea level rise contribution from surface mass loss in our high-resolution (15 km) regional climate projections is 17.8 ± 7.8 cm in SSP585, 7.9 cm more than in our RCP8.5 simulations using CMIP5 input. We identify a +1.3 °C greater Arctic Amplification and associated cloud and sea ice feedbacks in the CMIP6 SSP585 scenario as the main drivers. Additionally, an assessment of the GrIS sea level contribution across all emission scenarios highlights, that the GrIS mass loss in CMIP6 is equivalent to a CMIP5 scenario with twice the global radiative forcing.Peer reviewe

    Alternatives in a World of Crisis

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    Accelerated elastin degradation by age-disease interaction:a common feature in age-related diseases

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    Aging is a major driving force for many diseases but the relationship between chronological age, the aging process and age-related diseases is not fully understood. Fragmentation and loss of ultra-long-lived elastin are key features in aging and several age-related diseases leading to increased mortality. By comparing the relationship between age and elastin turnover with healthy volunteers, we show that accelerated elastin turnover by age-disease interaction is a common feature of age-related diseases

    Accelerated elastin degradation by age-disease interaction:a common feature in age-related diseases

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    Aging is a major driving force for many diseases but the relationship between chronological age, the aging process and age-related diseases is not fully understood. Fragmentation and loss of ultra-long-lived elastin are key features in aging and several age-related diseases leading to increased mortality. By comparing the relationship between age and elastin turnover with healthy volunteers, we show that accelerated elastin turnover by age-disease interaction is a common feature of age-related diseases

    Dissecting the action of an evolutionary conserved non-coding region on renin promoter activity

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    Elucidating the mechanisms of the human transcriptional regulatory network is a major challenge of the post-genomic era. One important aspect is the identification and functional analysis of regulatory elements in non-coding DNA. Genomic sequence comparisons between related species can guide the discovery of cis-regulatory sequences. Using this technique, we identify a conserved region CNSmd of ∼775 bp in size, ∼14 kb upstream of the renin gene. Renin plays a pivotal role for mammalian blood pressure regulation and electrolyte balance. To analyse the cis-regulatory role of this region in detail, we perform 132 combinatorial reporter gene assays in an in vitro Calu-6 cell line model. To dissect the role of individual subregions, we fit several mathematical models to the experimental data. We show that a multiplicative switch model fits best the experimental data and that one subregion has a dominant effect on promoter activity. Mapping of the sub-sequences on phylogenetic conservation data reveals that the dominant regulatory region is the one with the highest multi-species conservation score

    Reconstructions of the 1900–2015 Greenland ice sheet surface mass balance using the regional climate MAR model

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    With the aim of studying the recent Greenland ice sheet (GrIS) surface mass balance (SMB) decrease relative to the last century, we have forced the regional climate MAR (Modèle Atmosphérique Régional; version 3.5.2) model with the ERA-Interim (ECMWF Interim Re-Analysis; 1979–2015), ERA-40 (1958–2001), NCEP–NCARv1 (National Centers for Environmental Prediction–National Center for Atmospheric Research Reanalysis version 1; 1948–2015), NCEP–NCARv2 (1979–2015), JRA-55 (Japanese 55-year Reanalysis; 1958–2014), 20CRv2(c) (Twentieth Century Reanalysis version 2; 1900–2014) and ERA-20C (1900–2010) reanalyses. While all these forcing products are reanalyses that are assumed to represent the same climate, they produce significant differences in the MAR-simulated SMB over their common period. A temperature adjustment of +1 °C (respectively −1 °C) was, for example, needed at the MAR boundaries with ERA-20C (20CRv2) reanalysis, given that ERA-20C (20CRv2) is ∼ 1 °C colder (warmer) than ERA-Interim over Greenland during the period 1980–2010. Comparisons with daily PROMICE (Programme for Monitoring of the Greenland Ice Sheet) near-surface observations support these adjustments. Comparisons with SMB measurements, ice cores and satellite-derived melt extent reveal the most accurate forcing datasets for the simulation of the GrIS SMB to be ERA-Interim and NCEP– NCARv1. However, some biases remain in MAR, suggesting that some improvements are still needed in its cloudiness and radiative schemes as well as in the representation of the bare ice albedo.Results from all MAR simulations indicate that (i) the period 1961–1990, commonly chosen as a stable reference period for Greenland SMB and ice dynamics, is actually a period of anomalously positive SMB (∼ +40 Gt yr−1) compared to 1900–2010; (ii) SMB has decreased significantly after this reference period due to increasing and unprecedented melt reaching the highest rates in the 120- year common period; (iii) before 1960, both ERA-20C and 20CRv2-forced MAR simulations suggest a significant precipitation increase over 1900–1950, but this increase could be the result of an artefact in the reanalyses that are not well-enough constrained by observations during this period and (iv) since the 1980s, snowfall is quite stable after having reached a maximum in the 1970s. These MAR-based SMB and accumulation reconstructions are, however, quite similar to those from Box (2013) after 1930 and confirm that SMB was quite stable from the 1940s to the 1990s. Finally, only the ERA-20C-forced simulation suggests that SMB during the 1920–1930 warm period over Greenland was comparable to the SMB of the 2000s, due to both higher melt and lower precipitation than normal
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