Trends in MODIS and AERONET derived aerosol optical thickness over Northern Europe

Long-term Aqua and Terra MODIS (MODerate resolution Imaging Spectroradiometer) Collections 5.1 and 6.1 (c051 and c061, respectively) aerosol data have been combined with AERONET (AERosol RObotic NETwork) ground-based sun photometer observations to examine trends in aerosol optical thickness (AOT, at 550 nm) over Northern Europe for the months April to September. For the 1927 and 1559 daily coincident measurements that were obtained for c051 and c061, respectively, MODIS AOT varied by 86 and 90%, respectively, within the predicted uncertainty of one standard deviation of the retrieval over land (ΔAOT = ±0.05 ± 0.15·AOT). For the coastal AERONET site Gustav Dalen Tower (GDT), Sweden, larger deviations were found for MODIS c051 and c061 (79% and 75%, respectively, within predicted uncertainty). The Baltic Sea provides substantially better statistical representation of AOT than the surrounding land areas and therefore favours the investigations of trends in AOT over the region. Negative trends of 1.5% and 1.2% per year in AOT, based on daily averaging, were found for the southwestern Baltic Sea from MODIS c051 and c061, respectively. This is in line with a decrease of 1.2% per year in AOT at the AERONET station Hamburg. For the western Gotland Basin area, Sweden, negative trends of 1.5%, 1.1% and 1.6% per year in AOT have been found for MODIS c051, MODIS c061 and AERONET GDT, respectively. The strongest trend of –1.8% per year in AOT was found for AERONET Belsk, Poland, which can be compared to –1.5% per day obtained from MODIS c051 over central Poland. The trends in MODIS and AERONET AOT are nearly all statistically significant at the 95% confidence level. The strongest aerosol sources are suggested to be located southwest, south and southeast of the investigation area, although the highest prevalence of pollution events is associated with air mass transport from southwest.Peer reviewe

Spaceborne observations of low surface aerosol concentrations in the Stockholm region

© 2016 M. Tesche et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 International License, allowing third parties to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material for any purpose, even commercially, provided the original work is properly cited and states its license.This article investigates the feasibility of using spaceborne observations of aerosol optical thickness (AOT) derived with the Moderate Resolution Imaging Spectroradiometer (MODIS) for monitoring of fine particulate matter (PM2.5) in an environment of low aerosol loading. Previous studies of the AOT-to-PM2.5 relationship benefit from the large range of observed values. The Stockholm region features a comprehensive network of ground-based monitoring stations that generally show PM2.5 values <20 µg m−3. MODIS AOT at 555 nm is usually <0.20 and in good agreement with ground-based sun photometer observations in this region. We use MODIS Collection 5 AOT data with a horizontal resolution of 10 km×10 km and ground-based in-situ PM2.5 observations to derive an AOT-to-PM2.5 relationship that can be used to estimate fields of PM2.5. This has been carried out with respect to the months from April to September of the period 2000–2013. Relative average absolute deviations of 33–55 % (mean of 45 %) are obtained between MODIS-retrieved and ground-based PM2.5. The root mean square error is 0.2159 µg m−3 between retrieved and measured PM2.5. From spaceborne lidar observations, it is found that elevated aerosol layers are generally sparse in the Stockholm region. This favours remote sensing of PM2.5 from space. The deviations found between measured and retrieved PM2.5 are mainly attributed to infrequent situations of inhomogeneous aerosol layering for which column-integrated observations cannot be connected to surface conditions. Using MODIS Collection 6 data with a resolution of 3 km×3 km in a case study actually gives far fewer results than the coarser Collection 5 product. This is explained by the complex geography of the Stockholm region with a coastline and an abundance of lakes, which seems to induce biases in the retrieval of AOT at higher spatial resolution.Peer reviewedFinal Published versio

The sober rave project: investigating the acceptability and personal experiences of alcohol-free dance events

Our research is an innovative, European-wide collaborative investigation into the benefits of alcohol-free events, otherwise known as ‘sober raves’. Much of the existing behaviour work which focuses on preventing and regulating maladaptive alcohol misuse suggests individuals act rationally in choosing to consume alcohol. However, intentions and other cognitive mediators often fail to map onto actual behaviour and do not explain why individuals continue to carry out risky health-risk behaviours, despite being aware of the associated risks. Substance use is also often driven by the pursuit of pleasure, rather than by the avoidance of harms. For example, many young people get social pleasures from drinking alcohol, but due to limited alcohol-free socialising opportunities non-drinkers can feel stigmatised. Our research is focusing on the perceived acceptability, attitudes and perceptions of a range of alcohol-free events for young people across Europe. Following the first stage of this research project, we hope to explore how these types of events could be used as a means of reducing alcohol consumption in young people

Frequency-Dependent Current Noise through Quantum-Dot Spin Valves

We study frequency-dependent current noise through a single-level quantum dot connected to ferromagnetic leads with non-collinear magnetization. We propose to use the frequency-dependent Fano factor as a tool to detect single-spin dynamics in the quantum dot. Spin precession due to an external magnetic and/or a many-body exchange field affects the Fano factor of the system in two ways. First, the tendency towards spin-selective bunching of the transmitted electrons is suppressed, which gives rise to a reduction of the low-frequency noise. Second, the noise spectrum displays a resonance at the Larmor frequency, whose lineshape depends on the relative angle of the leads' magnetizations.Comment: 12 pages, 15 figure

Distributed Set-Based Observers Using Diffusion Strategy

Distributed estimation is more robust against single points of failure and requires less communication overhead compared to the centralized version. Among distributed estimation techniques, set-based estimation has gained much attention as it provides estimation guarantees for safety-critical applications and copes with unknown but bounded uncertainties. We propose two distributed set-based observers using interval-based and set-membership approaches for a linear discrete-time dynamical system with bounded modeling and measurement uncertainties. Both algorithms utilize a new over-approximating zonotopes intersection step named the set-based diffusion step. We use the term diffusion since our intersection of zonotopes formula resembles the traditional diffusion step in the stochastic Kalman filter. Our new zonotopes intersection takes linear time. Our set-based diffusion step decreases the estimation errors and the size of estimated sets and can be seen as a lightweight approach to achieve partial consensus between the distributed estimated sets. Every node shares its measurement with its neighbor in the measurement update step. The neighbors intersect their estimated sets constituting our proposed set-based diffusion step. We represent sets as zonotopes since they compactly represent high-dimensional sets, and they are closed under linear mapping and Minkowski addition. The applicability of our algorithms is demonstrated by a localization example. All used data and code to recreate our findings are publicly availabl

Does passive sound attenuation affect responses to pitch-shifted auditory feedback?

The role of auditory feedback in vocal production has mainly been investigated by altered auditory feedback (AAF) in real time. In response, speakers compensate by shifting their speech output in the opposite direction. Current theory suggests this is caused by a mismatch between expected and observed feedback. A methodological issue is the difficulty to fully isolate the speaker’s hearing so that only AAF is presented to their ears. As a result, participants may be presented with two simultaneous signals. If this is true, an alternative explanation is that responses to AAF depend on the contrast between the manipulated and the non-manipulated feedback. This hypothesis was tested by varying the passive sound attenuation (PSA). Participants vocalized while auditory feed- back was unexpectedly pitch shifted. The feedback was played through three pairs of headphones with varying amounts of PSA. The participants’ responses were not affected by the different levels of PSA. This suggests that across all three headphones, PSA is either good enough to make the manipulated feedback dominant, or differences in PSA are too small to affect the contribution of non-manipulated feedback. Overall, the results suggest that it is important to realize that non-manipulated auditory feedback could affect responses to AAF

Treatment with p33 Curtails Morbidity and Mortality in a Histone-Induced Murine Shock Model.

Collateral damage caused by extracellular histones has an immediate impact on morbidity and mortality in many disease models. A significant increase in the levels of extracellular histones is seen in critically ill patients with trauma and sepsis. We showed that histones are released from necrotic cells in patients with invasive skin infections. Under in vitro conditions, endogenous p33, an endothelial surface protein also known as the gC1q receptor, interacts with histones released from damaged endothelial cells. Functional analyses have revealed that recombinantly expressed p33 completely neutralizes the harmful features of histones, i.e. hemolysis of erythrocytes, lysis of endothelial cells and platelet aggregation. We also noted that mice treated with a sublethal dose of histones developed severe signs of hemolysis, thrombocytopenia and lung tissue damage already 10 min after inoculation. These complications were fully counteracted when p33 was administered together with the histones. Moreover, application of p33 significantly improved survival in mice receiving an otherwise lethal dose of histones. Together, our data suggest that treatment with p33 is a promising therapeutic approach in severe infectious diseases. © 2014 S. Karger AG, Basel

Retrieval of Water Vapour Profiles from GLORIA Nadir Observations

We present the first analysis of water vapour profiles derived from nadir measurements by the infrared imaging Fourier transform spectrometer GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere). The measurements were performed on 27 September 2017, during the WISE (Wave driven ISentropic Exchange) campaign aboard the HALO aircraft over the North Atlantic in an area between 37°–50°N and 20°–28°W. From each nadir recording of the 2-D imaging spectrometer, the spectral radiances of all non-cloudy pixels have been averaged after application of a newly developed cloud filter. From these mid-infrared nadir spectra, vertical profiles of H2O have been retrieved with a vertical resolution corresponding to five degrees of freedom below the aircraft. Uncertainties in radiometric calibration, temperature and spectroscopy have been identified as dominating error sources. Comparing retrievals resulting from two different a priori assumptions (constant exponential vs. ERA 5 reanalysis data) revealed parts of the flight where the observations clearly show inconsistencies with the ERA 5 water vapour fields. Further, a water vapour inversion at around 6 km altitude could be identified in the nadir retrievals and confirmed by a nearby radiosonde ascent. An intercomparison of multiple water vapour profiles from GLORIA in nadir and limb observational modes, IASI (Infrared Atmospheric Sounding Interferometer) satellite data from two different retrieval processors, and radiosonde measurements shows a broad consistency between the profiles. The comparison shows how fine vertical structures are represented by nadir sounders as well as the influence of a priori information on the retrievals

Two New Mutations in the CEL Gene Causing Diabetes and Hereditary Pancreatitis : How to Correctly Identify MODY8 Cases

Context Maturity onset diabetes of the young, type 8 (MODY8) is associated with mutations in the CEL gene, which encodes the digestive enzyme carboxyl ester lipase. Several diabetes cases and families have in recent years been attributed to mutations in CEL without any functional or clinical evidence provided. Objective To facilitate correct MODY8 diagnostics, we screened 2 cohorts of diabetes patients and delineated the phenotype. Methods Young, lean Swedish and Finnish patients with a diagnosis of type 2 diabetes (352 cases, 406 controls) were screened for mutations in the CEL gene. We also screened 58 Czech MODY cases who had tested negative for common MODY genes. For CEL mutation-positive subjects, family history was recorded, and clinical investigations and pancreatic imaging performed. Results Two cases (1 Swedish and 1 Czech) with germline mutation in CEL were identified. Clinical and radiological investigations of these 2 probands and their families revealed dominantly inherited insulin-dependent diabetes, pancreatic exocrine dysfunction, and atrophic pancreas with lipomatosis and cysts. Notably, hereditary pancreatitis was the predominant phenotype in 1 pedigree. Both families carried single-base pair deletions in the proximal part of the CEL variable number of tandem repeat (VNTR) region in exon 11. The mutations are predicted to lead to aberrant protein tails that make the CEL protein susceptible to aggregation. Conclusion The diagnosis of MODY8 requires a pancreatic exocrine phenotype and a deletion in the CEL VNTR in addition to dominantly inherited diabetes. CEL screening may be warranted also in families with hereditary pancreatitis of unknown genetic etiology.Peer reviewe