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Atmospheric dust has significant impact on the Earth’s climate system but different aspects of the impact remain highly uncertain. These uncertainties can be attributed to the larger spatial-temporal variability of aerosol dust and its complex interaction with other atmospheric constituents, radiation, and clouds. To investigate Saharan dust plumes in Western Europe, we collected a comprehensive set of observational data and compared it with global transport model simulations to achieve a better understanding of the distribution, evolution, and potential impact of dust plumes in southwest Germany for four characteristic cases during April 2018, February 2021, June 2021, and March 2022. Remote sensing methods including lidars and sunphotometers were used to study the dust events employing different retrieval methods and comparing these retrievals with ICON-ART simulations. In situ measurements (e.g. Optical Particle Counters (OPC), Aerodynamic Particle Sizer (APS), and Scanning Mobility Particle Sizer (SMPS)) were used to determine e.g. size distributions and particle number concentrations of dust particles, which were compared for suitable cases with remote sensing measurements and ICON-ART simulations. One major objective was to quantify the uncertainties of the different measurements and retrieval methods including a demonstration how useful scanning lidar measurements can be in addition to vertical lidar and sun photometer data and what kind of understanding of the aerosol properties can be achieved by combining the different measurement techniques. Furthermore, we compared these observational data with predictions by the state-of-the-art transport model, ICON-ART, to evaluate the quality of its predictions for different meteorological conditions. In this contribution, we will discuss the systematic comparison between observational data and ICON-ART model results.

Aerosols such as mineral dust particles reduce the surface albedo when deposited on snow. This leads to increased absorption of solar radiation. Especially in spring, this phenomenon can lead to increased snowmelt, which triggers further feedbacks at the land surface and in the atmosphere. Quantifying the magnitude of dust-induced variations is difficult because of the high variability in the spatial distribution of mineral dust and snow. We present an extension of a fully coupled atmospheric and land surface model system to investigate the effects of mineral dust on snow albedo across Eurasia. In a comprehensive ensemble simulation study, we investigated the short-term effects of an extreme Saharan dust deposition event in 2018. We found region-dependent feedbacks. Mountainous regions and areas near the snowline showed a strong impact from mineral dust deposition. The former showed a particularly strong decrease in snow depth. For instance, in the Caucasus Mountains we found a mean significant decrease in snow depth of -1.4 cm after one week. The latter showed a stronger feedback effect on surface temperature. In the flat region around the snow line, we found a mean significant surface warming of 0.9 K after one week. This study shows that the effects of mineral dust deposition depend on several factors. Primarily, these are elevation, slope, snow depth, and fraction of snow cover. Therefore, especially in complex terrain, it is necessary to use fully coupled models to study the effects of mineral dust on the snowpack and the atmosphere.

Aerosols interact with radiation and clouds and thereby disturb radiative budget and temperature structure in the atmosphere. To account for these effects, numerical weather prediction models rely on climatological mean concentrations. This simplification may lead to large errors in the forecasted cloud cover and radiative fluxes especially during major aerosol events. For example, Saharan dust events often coincide with significant errors in shortwave radiation and thus, day-ahead photovoltaic forecasts in Europe. In this study we investigate errors in the short-range forecasts during Saharan dust outbreaks in March 2021, analyze possible causes and explore the solutions. We use the data from pre-operational forecasts performed with the ICOsahedral Nonhydrostatic model with Aerosols and Reactive Trace gases (ICON-ART) based on two experiments: without dust effects and with direct dust effect only. We compare model data with the measurements from satellite and in-situ instruments. The results reveal that the inclusion of direct radiative effects from prognostic dust improves the forecast in surface radiation during clear-sky conditions. However, dusty Cirrus clouds are strongly underestimated, pointing to the importance of representing indirect effects. To fill this gap, we develop and test corresponding sub-grid parameterization for dusty Cirrus in the ICON-ART model. Only with help of this parameterization ICON-ART is able to simulate the formation of the dusty cirrus, which leads to substantial improvements in cloud cover and radiative fluxes compared to simulations without this parameterization. This study confirms that a reliable photovoltaic forecast requires explicit treatment of aerosol-cloud-radiation in numerical weather forecast systems.

Light-absorbing impurities such as mineral dust can play a major role in reducing the albedo of snow surfaces. Particularly in spring, deposited dust particles lead to increased snow melt and trigger further feedbacks at the land surface and in the atmosphere. Quantifying the extent of dust-induced variations is difficult due to the high variability in the spatial distribution of mineral dust and snow. We present an extension of a fully coupled atmospheric and land surface model system to address the impact of mineral dust on the snow albedo across Eurasia. We evaluated the short-term effects of Saharan dust in a case study. To obtain robust results, we performed an ensemble simulation followed by statistical analysis. Mountainous regions showed a strong impact of dust deposition on snow depth. We found a mean significant reduction of -1.4 cm in the Caucasus Mountains after one week. However, areas with flat terrain near the snow line also showed strong effects despite lower dust concentrations. Here, the feedback to dust deposition was more pronounced as increase in surface temperature and air temperature. In the region surrounding the snow line, we found an average significant surface warming of 0.9 K after one week. This study shows that the impact of mineral dust deposition depends on several factors. Primarily, these are altitude, slope, snow depth, and snow cover fraction. Especially in complex terrain, it is therefore necessary to use fully coupled models to investigate the effects of mineral dust on snow pack and the atmosphere.

Type 2 diabetes (T2D) represents a multifactorial metabolic disease with a strong genetic predisposition. Despite elaborate efforts in identifying the genetic variants determining individual susceptibility towards T2D, the majority of genetic factors driving disease development remain poorly understood. With the aim to identify novel T2D risk genes we previously generated an N2 outcross population using the two inbred mouse strains New Zealand obese (NZO) and C3HeB/FeJ (C3H). A linkage study performed in this population led to the identification of the novel T2D-associated quantitative trait locus (QTL)

Dusty cirrus clouds are extended optically thick cirrocumulus decks that occur during strong mineral dust events. So far they have been mostly documented over Europe associated with dust-infused baroclinic storms. Since today's numerical weather prediction models neither predict mineral dust distributions nor consider the interaction of dust with cloud microphysics, they cannot simulate this phenomenon. We postulate that the dusty cirrus forms through a mixing instability of moist clean air with drier dusty air. A corresponding sub-grid parameterization is suggested and tested in the ICON-ART model. Only with help of this parameterization ICON-ART is able to simulate the formation of the dusty cirrus, which leads to substantial improvements in cloud cover and radiative fluxes compared to simulations without this parameterization. A statistical evaluation over six Saharan dust events with and without observed dusty cirrus shows robust improvements in cloud and radiation scores. The ability to simulate dusty cirrus formation removes the linear dependency on mineral dust aerosol optical depth from the bias of the radiative fluxes. This suggests that the formation of dusty cirrus clouds is the dominant aerosol-cloud-radiation effect of mineral dust over Europe.

OBJECTIVE: This study investigated whether blood concentrations of leptin, ghrelin, and adiponectin are affected by acute total sleep deprivation in a sex- and weight-specific manner. METHODS: A total of 44 participants (mean age 24.9 years; 20 women; 19 with obesity) participated in a crossover design, including one night of sleep deprivation and one night of sleep in the laboratory. After each night, fasting blood was collected. RESULTS: After sleep deprivation, fasting levels of leptin were lower (mean [SE], vs. sleep: 17.3 [2.6] vs. 18.6 [2.8] ng/mL), whereas those of ghrelin and adiponectin were higher (839.4 [77.5] vs. 741.4 [63.2] pg/mL and 7.5 [0.6] vs. 6.8 [0.6] μg/mL, respectively; all p

For an efficient integration of photovoltaic (PV) energy into the power grids, more accurate forecasts of the expected PV-power production are needed. However, most operational numerical weather prediction models rely on an aerosol climatology and ignore the spatio-temporal variability of the atmospheric aerosol. For specific weather conditions like during mineral dust outbreaks or major wildfire events, the negligence of prognostic aerosol often leads to significant deficiencies in the operational forecasts, however.At Deutscher Wetter­dienst (DWD) and Karlsruhe Insti­tute of Technology (KIT) the project “PermaStrom” aims at the operational prediction of various natural aerosol species to improve radiation forecasts. Emission, transport and deposition of mineral dust, black carbon from vegetation fires, and sea salt are thus explicitly simulated in the ICON-ART model system. In the model, direct aerosol effects on radiation are considered using state-of-the-art optical properties. Microphysical effects of aerosol acting as cloud condensation nuclei (CCN) and ice nucleating particles (INPs) are investigated in a high-resolution regional model with the long-term goal to improve the parameterization of aerosol-cloud effects in global models.Aerosol-cloud-radiation effects are studied in a regional ICON-ART model with 2 km grid spacing with an aerosol-aware two-moment bulk microphysics scheme. In addition, first steps are made towards a global ensemble system for aerosol forecasts using ICON-ART. This will allow to quantify the uncertainty of the forecasts. A multi-fidelity ensemble, which combines ICON-ART and ICON simulations to optimally sample the aerosol- and flow-dependent variability, is used to keep the computational processing manageable. The ICON-ART simulations are validated with aerosol and radiation measurements at surface stations as well as cloud, aerosol and radiation products from satellites and ceilometers.We will give an overview of the ICON-ART configuration of the pre-operational real-time global aerosol prediction system at DWD. This includes aspects like mineral dust, sea salt, and wildfire emissions. For the latter, a machine learning emulator of the plume rise model is currently being developed.

The evolution and the properties of a Saharan dust plume were studied near the city of Karlsruhe in southwest Germany (8.4298°E, 49.0953°N) from 7 to 9 April 2018, combining a scanning LiDAR (90°, 30°), a vertically pointing LiDAR (90°), a sun photometer, and the transport model ICON-ART. Based on this Saharan dust case, we discuss the advantages of a scanning aerosol LiDAR and validate a method to determine LiDAR ratios independently. The LiDAR measurements at 355 nm showed that the dust particles had backscatter coefficients of 0.86 ± 0.14 Mm−1 sr−1, extinction coefficients of 40 ± 0.8 Mm−1, a LiDAR ratio of 46 ± 5 sr, and a linear particle depolarisation ratio of 0.27 ± 0.023. These values are in good agreement with those obtained in previous studies of Saharan dust plumes in Western Europe. Compared to the remote sensing measurements, the transport model predicted the plume arrival time, its layer height, and its structure quite well. The comparison of dust plume backscatter values from the ICON-ART model and observations for two days showed a correlation with a slope of 0.9 ± 0.1 at 355 nm. This work will be useful for future studies to characterise aerosol particles employing scanning LiDARs.

Urban aerosol pollution was analyzed over the Moscow megacity region using COSMO-ART chemical transport model and intensive measurement campaigns at the Moscow State University Meteorological Observatory (MSU MO, 55.707° N, 37.522° E) during April-May period in 2018 and 2019. We analyzed mass concentrations of Particulate Matter with diameter smaller 10 micron (PM10), Black Carbon (BC), and aerosol gas precursors (NOx, SO2, CHx) as well as columnar aerosol parameters for fine and coarse modes together with different meteorological parameters including an index characterizing the Intensity of Particle Dispersion (IPD). Both model and experimental datasets have shown a statistically significant linear correlation of BC with NO2 and PM10 mass concentrations, which indicates mostly common sources of emissions of these substances. There was a pronounced increase in the BC / PM10 ratio from 0.7 % to 5.9 % with the decrease in IPD index related to the amplification of the atmospheric stratification. We also found an inverse dependence between the BC / PM10 ratio and columnar single scattering albedo (SSA) for the intense air mixing conditions. This dependence together with the obtained negative correlation between wind speed and BC / PM10 may serve an indicator of changes in the absorbing properties of the atmosphere due to meteorological factors. On average, relatively low for urban regions BC / PM10 ratio of 4.7 % is the cause of the observed relatively high SSA = 0.94 in Moscow. Using long-term parallel aerosol optical depth (AOD) measurements over the 2006–2020 period at the MSU MO and in upwind clean background conditions at Zvenigorod Scientific Station (ZSS) of the IAP RAS (55.7° N, 36.8° E), we estimated the urban component of AOD (AODurb) and some other parameters as the differences at these sites. The average AODurb at 550 nm was about 0.021 with more than 85 % of fine aerosol mode. The comparisons between AODurb obtained from model and measurements during the experiment have revealed a similar level of aerosol pollution of about AODurb = 0.015–0.019, which comprised 15–19 % of the total AOD at 550 nm. The urban component of PM10 (PM10urb) was about 0.016 mg m-3 according to the measurements and 0.006 mg m-3 according to the COSMO-ART simulations. We obtained a pronounced diurnal cycle of PM10urb and urban BC (BCurb), as well as their strong correlation with the IPDs. With the IPD index change from 3 to 1 at night, there was about 4 times increase in PM10urb (up to 0.030–0.040 mg m-3) and 3 times increase in BCurb (up to 0.003–0.0035 mg m-3). At the same time, no pronounced daily cycle was found for the columnar urban aerosol component (AODurb), although there is a slight tendency to the increase in model AODurb at night. We also obtained a close relationship between the calculated and measured PM10urb values, their dependence on IPD index, and the pronounced growth of PM10urb with the PM10 increase.

OBJECTIVE The lateral parabrachial nucleus (lPBN) in the brainstem has emerged as a key area involved in feeding control that is targeted by several circulating anorexigenic hormones. Here, the objective was to determine whether the lPBN is also a relevant site for the orexigenic hormone ghrelin, inspired by studies in mice and rats showing that there is an abundance of ghrelin receptors in this area. METHODS This study first explored whether iPBN cells respond to ghrelin involving Fos mapping and electrophysiological studies in rats. Next, rats were injected acutely with ghrelin, a ghrelin receptor antagonist, or vehicle into the lPBN to investigate feeding-linked behaviors. RESULTS Curiously, ghrelin injection (intracerebroventricular or intravenous) increased Fos protein expression in the lPBN yet the predominant electrophysiological response was inhibitory. Intra-lPBN ghrelin injection increased chow or high-fat diet intake, whereas the antagonist decreased chow intake only. In a choice paradigm, intra-lPBN ghrelin increased intake of chow but not lard or sucrose. Intra-lPBN ghrelin did not alter progressive ratio lever pressing for sucrose or conditioned place preference for chocolate. CONCLUSIONS The lPBN is a novel locus from which ghrelin can alter consummatory behaviors (food intake and choice) but not appetitive behaviors (food reward and motivation).

To nominate novel disease genes for obesity and type 2 diabetes (T2D), we recently generated two mouse backcross populations of the T2D-susceptible New Zealand Obese (NZO/HI) mouse strain and two genetically different, lean and T2D-resistant strains, 129P2/OlaHsd and C3HeB/FeJ. Comparative linkage analysis of our two female backcross populations identified seven novel body fat-associated quantitative trait loci (QTL). Only the locus Nbw14 (NZO body weight on chromosome 14) showed linkage to obesity-related traits in both backcross populations, indicating that the causal gene variant is likely specific for the NZO strain as NZO allele carriers in both crosses displayed elevated body weight and fat mass. To identify candidate genes for Nbw14, we used a combined approach of gene expression and haplotype analysis to filter for NZO-specific gene variants in gonadal white adipose tissue, defined as the main QTL-target tissue. Only two genes, Arl11 and Sgcg, fulfilled our candidate criteria. In addition, expression QTL analysis revealed cis-signals for both genes within the Nbw14 locus. Moreover, retroviral overexpression of Sgcg in 3T3-L1 adipocytes resulted in increased insulin-stimulated glucose uptake. In humans, mRNA levels of SGCG correlated with body mass index and body fat mass exclusively in diabetic subjects, suggesting that SGCG may present a novel marker for metabolically unhealthy obesity. In conclusion, our comparative-cross analysis could substantially improve the mapping resolution of the obesity locus Nbw14. Future studies will throw light on the mechanism by which Sgcg may protect from the development of obesity.

Changes in intracellular CoA levels are known to contribute to the development of non-alcoholic fatty liver disease (NAFLD) in type 2 diabetes (T2D) in human and rodents. However, the underlying genetic basis is still poorly understood. Due to their diverse susceptibility towards metabolic diseases, mouse inbred strains have been proven to serve as powerful tools for the identification of novel genetic factors that underlie the pathophysiology of NAFLD and diabetes. Transcriptome analysis of mouse liver samples revealed the nucleoside diphosphate linked moiety X-type motif Nudt19 as novel candidate gene responsible for NAFLD and T2D development. Knockdown (KD) of Nudt19 increased mitochondrial and glycolytic ATP production rates in Hepa 1-6 cells by 41% and 10%, respectively. The enforced utilization of glutamine or fatty acids as energy substrate reduced uncoupled respiration by 41% and 47%, respectively, in non-target (NT) siRNA transfected cells. This reduction was prevented upon Nudt19 KD. Furthermore, incubation with palmitate or oleate respectively increased mitochondrial ATP production by 31% and 20%, and uncoupled respiration by 23% and 30% in Nudt19 KD cells, but not in NT cells. The enhanced fatty acid oxidation in Nudt19 KD cells was accompanied by a 1.3-fold increased abundance of Pdk4. This study is the first to describe Nudt19 as regulator of hepatic lipid metabolism and potential mediator of NAFLD and T2D development.

During the AeroRadCity-2018 spring aerosol experiment at the Moscow State University Meteorological Observatory the aerosol properties of the atmosphere and radiative aerosol effects were analyzed using a wide complex of measurements and model COSMO-ART simulations over Moscow domain. The program of measurements consisted of columnar aerosol AERONET retrievals, surface PM10, black carbon (BC) and aerosol gas precursors mass concentrations, as well as radiative measurements under various meteorological conditions. We obtained a positive statistically significant dependence of total and fine aerosol optical depth (AOD) mode (R2 ~0.4) with PM concentrations. This dependence has revealed a pronounced bifurcation point around PM10=0.04 mgm-3. The modelled BC concentration is in agreement with the observations and has a pronounced correlation with PM, but not with the AODs. The analysis of radiative effects of aerosol has revealed up to 30% loss for UV irradiance and 15% - for shortwave irradiance at high AOD in Moscow. Much intensive radiation attenuation is observed in the afternoon when remote pollution sources may affect solar fluxes at elevated boundary layer conditions. Negative (cooling) radiative forcing effect at the top of the atmosphere from -18 Wm-2 to -4 Wm-2 has been evaluated. Mean difference in visible AOD between urban and background conditions in Moscow and Zvenigorod was about 0.01 according to measurements and model simulations, while in some days the difference may increase up to 0.05. The generation of urban aerosol was shown to be more favorable in conditions with low intensity of pollutant dispersion, when mean deltaAOD550 was doubled from 0.01 to 0.02.

Im Zusammenhang mit der geplanten Energiewende in Deutschland und Europa werden exakte Photovoltaikertragsprognosen immer wichtiger. In den meisten operationellen Wettervorhersagemodellen bleiben jedoch Aerosol- Strahlungs- und Wolkenwechselwirkungen bisher unberücksichtigt, was besonders bei Sonderwetterlagen wie Saharastaub oder Waldbrandaerosolepisoden zu Fehlprognosen des PV Ertrags führen kann. Das vom BMWi geförderte Verbundprojekt (Partner: DWD, KIT, Meteocontrol) PermaStrom (Photovoltaikertragsprognose zum besseren Management des Einflusses des atmosphärischen Aerosols auf die Stromnetze in Deutschland und Europa) untersucht deshalb unter anderem die Parametrisierung von Aerosol-Wolken-Strahlungs-Wechselwirkungen im ICON-ART Vorhersagemodell. Zur Validierung des modellierten Bedeckungsgrades der 24h Modellvorhersage während Saharastaubereignissen wurden Ceilometerdaten verwendet. Ceilometer sind bodengestützte Fernerkundungssensoren, welche nach dem Lidar-Prinzip zeitlich und vertikal hoch aufgelöst die Höhe von Wolkenunterkanten sowie Profile der Aerosolrückstreuung messen. Aus Ceilometerdaten an 13 verschiedener Stationen in Deutschland wurden stündliche Werte des Bedeckungsgrades während Saharastaubereignissen vertikal aufgelöst (500m, von 0-12000m) extrahiert und mit den stündlichen ICON-ART Vorhersagen sowie einem Kontrollexperiment ohne Staub verglichen. Die Auswertung der mittleren Abweichung des Bedeckungsgrades zwischen Modell und Ceilometer zeigt in Wintermonaten im Mittel über die 13 Stationen eine Überschätzung der modellierten bodennahen Bewölkung (0-1000m) zwischen 2-10% und der hohen Bewölkung (6000-10000m) zwischen 1-9%, während bei der mittelhohen Bewölkung (1500m - 4000m) der modellierte Bedeckungsgrad um 1-4% geringer ist als in den Ceilometermessungen. Auffällig ist auch die Unterschätzung des modellierten Bedeckungsgrades bis zu 4% bei Wolken über 10000m. Dies ist insbesondere interessant, da sich gezeigt hat, dass hohe Zirruswolken im Zusammenhang mit Saharastaubereignissen bislang häufig nicht korrekt vorhergesagt werden können. Für die Sommermonate finden sich insgesamt größere Abweichungen, besonders oberhalb 8000m wird der Bedeckungsgrad modellseitig um bis zu 15% überschätzt. Der ICON-ART-Lauf mit Staub weist gegenüber dem Kontrollexperiment ohne Staub in zwei von vier Monaten geringere Abweichungen (um 8-10% geringer) in Bezug auf die aus Ceilometermessungen bestimmten Bedeckungsgrade auf. Noch deutlicher wird die Verbesserung bei der gesonderten Betrachtung von Tag-und Nachtzeiten. Hier ergibt sich während der Nachtstunden eine verbesserte Modellierung der Bewölkung zwischen 1 und 11% in allen untersuchten Monaten. Tagsüber ergaben sich Verbesserungen in drei von 4 Monaten von 10 bis 26% im Vergleich zum ICON-ART Kontrollexperiment ohne Staubberücksichtigung. Die Ergebnisse zeigen, dass das ICON-ART Modell, das bisher nur den direkten und semi-direkten Effekt des Aerosols auf die Strahlung berücksichtigt, bereits eine verbesserte Vorhersage der Bewölkungssituation bei Saharastaubereignissen liefern kann. Im weiteren Projektverlauf ist eine Erweiterung des Modelles um zusätzliche Aerosolkomponenten und eine Einbeziehung der mikrophysikalischen Effekte des Aerosols auf die Wolkenbildung geplant.

The evolution and the properties of a Saharan dust plume were studied near the city of Karlsruhe in south-west Germany (8.4298° E, 49.0953° N) from April 7 to 9, 2018 combining a scanning LIDAR (90°, 30°), a vertical LIDAR (90°), a sun photometer, and the transport model ICON-ART. The LIDAR measurements show that the dust particles had backscatter coefficients of 0.86 ± 0.14 Mm−1 Sr−1, an extinction coefficient of 40 ± 0.8 Mm−1, a LIDAR ratio of 46 ± 5 sr, and a particle depolarization ratio of 0.33 ± 0.07. These values are in good agreement with those obtained in previous studies of Saharan dust plumes in Western Europe. Compared to the remote sensing measurements, the model simulation predicts the plume arrival time, its layer height, and structure very well but overestimates the backscatter coefficient. In this manuscript, we discuss the complementarity and advantages of the different measurement methods as well model simulations to predict Saharan dust plumes. Main conclusions are that the ICON-ART model can predict the structure of Saharan dust plumes very well but overestimates the backscatter coefficients by a factor of 2.2 ± 0.16 at 355 nm and underestimates the aerosol optical depth (AOD) by a factor of 1.5 ± 0.11 at 340 nm for this Saharan dust plume event. Employing a scanning aerosol LIDAR allows determining backscatter coefficient, particle depolarization ratio and especially LIDAR ratio of Saharan dust both for daytime and nighttime independently. Combining LIDAR with sun photometer data allows constraining aerosol optical depth in different ways and determining column integrated LIDAR ratios. These comprehensive datasets allow for a better understanding of Saharan dust plumes in Western Europe.

The hormone fibroblast growth factor 21 (FGF21) modulates tissue metabolism and circulates at higher levels in metabolic conditions associated with chronic sleep-wake disruption, such as type 2 diabetes and obesity. In the present study, we investigated whether acute sleep loss impacts circulating levels of FGF21 and tissue-specific production, and response pathways linked to FGF21. A total of 15 healthy normal-weight young men participated in a randomised crossover study with two conditions, sleep loss versus an 8.5-hr sleep window. The evening before each intervention, fasting blood was collected. Fasting, post-intervention morning skeletal muscle and adipose tissue samples underwent quantitative polymerase chain reaction and DNA methylation analyses, and serum FGF21 levels were measured before and after an oral glucose tolerance test. Serum levels of FGF21 were higher after sleep loss compared with sleep, both under fasting conditions and following glucose intake (~27%-30%, p = 0.023). Fasting circulating levels of fibroblast activation protein, a protein which can degrade circulating FGF21, were not altered by sleep loss, whereas DNA methylation in the FGF21 promoter region increased only in adipose tissue. However, even though specifically the muscle exhibited transcriptional changes indicating adverse alterations to redox and metabolic homeostasis, no tissue-based changes were observed in expression of FGF21, its receptors, or selected signalling targets, in response to sleep loss. In summary, we found that acute sleep loss resulted in increased circulating levels of FGF21 in healthy young men, which may occur independent of a tissue-based stress response in metabolic peripheral tissues. Further studies may decipher whether changes in FGF21 signalling after sleep loss modulate metabolic outcomes associated with sleep or circadian disruption.

Aim: MicroRNAs play an important role in the maintenance of cellular functions by fine-tuning gene expression levels. The aim of the current study was to identify genetically caused changes in microRNA expression which associate with islet dysfunction in diabetic mice. Methods: To identify novel microRNAs involved in islet dysfunction, transcriptome and miRNome analyses were performed in islets of obese, diabetes-susceptible NZO and diabetes-resistant B6-ob/ob mice and results combined with quantitative trait loci (QTL) and functional in vitro analysis. Results: In islets of NZO and B6-ob/ob mice, 94 differentially expressed microRNAs were detected, of which 11 are located in diabetes QTL. Focusing on conserved microRNAs exhibiting the strongest expression difference and which have not been linked to islet function, miR-205-5p was selected for further analysis. According to transcriptome data and target prediction analyses, miR-205-5p affects genes involved in Wnt and calcium signalling as well as insulin secretion. Over-expression of miR-205-5p in the insulinoma cell line INS-1 increased insulin expression, left-shifted the glucose-dependence of insulin secretion and supressed the expression of the diabetes gene TCF7L2. The interaction between miR-205-5p and TCF7L2 was confirmed by luciferase reporter assay. Conclusion: MiR-205-5p was identified as relevant microRNA involved in islet dysfunction by interacting with TCF7L2. (Less)

Summary: An insufficient adaptive beta-cell compensation is a hallmark of type 2 diabetes (T2D). Primary cilia function as versatile sensory antennae regulating various cellular processes, but their role on compensatory beta-cell replication has not been examined. Here, we identify a significant enrichment of downregulated, cilia-annotated genes in pancreatic islets of diabetes-prone NZO mice as compared with diabetes-resistant B6-ob/ob mice. Among 327 differentially expressed mouse cilia genes, 81 human orthologs are also affected in islets of diabetic donors. Islets of nondiabetic mice and humans show a substantial overlap of upregulated cilia genes that are linked to cell-cycle progression. The shRNA-mediated suppression of KIF3A, essential for ciliogenesis, impairs division of MIN6 beta cells as well as in dispersed primary mouse and human islet cells, as shown by decreased BrdU incorporation. These findings demonstrate the substantial role of cilia-gene regulation on islet function and T2D risk. : Kluth et al. identify a significant enrichment of cilia-annotated genes that are differentially expressed in pancreatic islets of obese mice. Many of the genes were also linked to human T2D, suggesting that dysregulation of cilia-associated genes may participate in T2D risk. Keywords: beta-cell proliferation, cilia genes, human pancreatic islets, islet transcriptomics, New Zealand Obese mouse, pathway enrichment analysis, primary cilia, type 2 diabetes

Clouds play a key role in the atmosphere by completing the hydrological cycle and transferring water from the atmosphere to the earth's surface on the one hand, and affecting terrestrial radiation and solar radiation on the other hand. Although cloud properties are primarily affected by atmospheric dynamics, cloud microphysical features, which themselves are influenced by the number and chemical composition of aerosols that act as cloud condensation nuclei (CCN) and ice nuclei (IN) within cloud droplets, also affect cloud formation. The extent and quality of aerosols impact on cloud formation is one of the important open question of climate science. Volcanoes, which are a rich source of various chemical compounds, can help to improve the understanding of the effects of aerosols on clouds by providing a natural laboratory with locally high aerosol conditions adjacent to an unperturbed environment. In the present study, the impacts of changing the aerosol number concentration on clouds are investigated using the ICON-ART model. For this purpose, the Holuhraun volcano, which erupted on the island of Iceland in 2014, was simulated. It emitted small amounts of volcanic ash, and large emissions of gases primarily sulfur dioxide (SO2), which formed sulfate particles serving as CCN. Three simulations representing low, control, and high emission conditions were conducted. For the control simulation, the source strength of SO2 was based on the estimate by Malavelle et al. (2017). This rate, then, was reduced to one-fifth for the low emission experiment and increased by a factor of 5 for the high emission experiment.First results indicate that increasing the source strength of SO2 is associated with an enhancement of sulfate aerosol number concentration and thus an increase of the number of cloud droplets, but with strongly nonlinear effects. For clouds within the volcanic plume, droplet concentrations are already high in the low emission scenario and do not increase significantly with higher emission strengths, partly due to model limitations. In addition, the effect of aerosols on the formation of cloud droplets is strongly dependent on environmental factors such as updraft velocity and supersaturation.Keywords: Aerosol, Cloud, ICON-ART Model, Holuhraun eruption

Atmospheric aerosol has a noticeable effect on the microphysical and optical properties of the atmosphere, solar radiation, temperature and humidity conditions, thereby determining the quality of the forecast of important meteorological elements and affecting the regional climate and the dynamics of geochemical processes. Using the results of the spring AeroRadCity experiment at the MSU Meteorological Observatory in 2018-2019, and numerical calculations on the base of modern COSMO and COSMO-ART mesoscale models using Russian (-Ru) configurations we determined the level and main features of urban air/aerosol pollution, and assessed its magnitude and its impact on the radiative and meteorological characteristics of the atmosphere in typical conditions (Chubarova et al., 2020). In the context of the coronavirus pandemic in 2020, especially during the period of lockdown in the spring, there was a significant decrease in emissions of pollutants in many countries, including Russia. The aim of this study is to show the consequences of decrease in emissions of pollutants on the air quality and on urban aerosol pollution. A special attention is paid to the division between the effects of meteorological factors and the influence of pollution emission on aerosol and gas concentration. The effects of the air pollution decrease on solar radiation and air temperature during this period have been analyzed using COSMO-Ru-ART model. For a more detailed study of the observed spatial aerosol distribution on solar radiation and air temperature, we have developed a methodology of the implementation of the satellite aerosol optical thickness (AOT) data in the COSMO-Ru model. Using this approach we evaluated the radiative and temperature effects observed due to aerosol in typical conditions during the spring of 2018-2019 and during the period of lockdown in the spring of 2020 under various meteorological conditions. To do this, the satellite AOT data from the MAIAC/MODIS algorithm and aerosol measurements from Cimel sun photometers data were used for characterising the urban aerosol in typical and lockdown conditions. We also discuss the aerosol indirect effects on cloud properties using an experimental scheme of COSMO-Ru model and their influence on solar radiation and surface temperature during this period. The aerosol study has been partially supported by the RSF grant number 18-17-00149; the analysis of gas species has been partially funded by the megagrant number 2020-220-08-5835.Reference:Chubarova N.Ye., Ye.Yu. Zhdanova., Ye.Ye. Androsova, A.A. Kirsanov, M.V. Shatunova, Yu.O. Khlestova, Ye.V. Volpert, A.A. Poliukhov, I.D. Eremina, D.V. Vlasov, O.B. Popovicheva, A.S. Ivanov, Ye.V. Gorbarenko, Ye.I. Nezval, D.V. Blinov, G.S. Rivin. The aerosol urban pollution and its effects on weather, regional climate and geochemical processes: Monograph / Edited by N.Ye. Chubarova – Moscow, MAKS Press, 2020. 339 pp. ISBN 978-5-317-06464-8

Biomass Burning (BB) aerosol has attracted considerable attention due to its detrimental effects on climate through its radiative properties. In Africa, fire patterns are anticorrelated with the southward-northward movement of the intertropical convergence zone (ITCZ). Each year between June and September, BB occurs in the southern hemisphere of Africa, and aerosols are carried westward by the African Easterly Jet (AEJ) and advected at an altitude of between 2 and 4 km. Observations made during a field campaign of Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) (Knippertz et al., Bull Am Meteorol Soc 96:1451–1460, 2015) during the West African Monsoon (WAM) of June–July 2016 have revealed large quantities of BB aerosols in the Planetary Boundary Layer (PBL) over southern West Africa (SWA).This chapter examines the effects of the long-range transport of BB aerosols on the climate over SWA by means of a modeling study, and proposes several adaptation and mitigation strategies for policy makers regarding this phenomenon. A high-resolution regional climate model, known as the Consortium for Small-scale Modelling – Aerosols and Reactive Traces (COSMO-ART) gases, was used to conduct two set of experiments, with and without BB emissions, to quantify their impacts on the SWA atmosphere. Results revealed a reduction in surface shortwave (SW) radiation of up to about 6.5 W m−2 and an 11% increase of Cloud Droplets Number Concentration (CDNC) over the SWA domain. Also, an increase of 12.45% in Particulate Matter (PM25) surface concentration was observed in Abidjan (9.75 μg m−3), Accra (10.7 μg m−3), Cotonou (10.7 μg m−3), and Lagos (8 μg m−3), while the carbon monoxide (CO) mixing ratio increased by 90 ppb in Abidjan and Accra due to BB. Moreover, BB aerosols were found to contribute to a 70% increase of organic carbon (OC) below 1 km in the PBL, followed by black carbon (BC) with 24.5%. This work highlights the contribution of the long-range transport of BB pollutants to pollution levels in SWA and their effects on the climate. It focuses on a case study of 3 days (5–7 July 2016). However, more research on a longer time period is necessary to inform decision making properly.This study emphasizes the need to implement a long-term air quality monitoring system in SWA as a method of climate change mitigation and adaptation.