Evaluation of a coupled dispersion and aerosol process model against measurements near a major road

International audienceA field measurement campaign was conducted near a major road "Itäväylä" in an urban area in Helsinki in 17?20 February 2003. Aerosol measurements were conducted using a mobile laboratory "Sniffer" at various distances from the road, and at an urban background location. Measurements included particle size distribution in the size range of 7 nm?10 ?m (aerodynamic diameter) by the Electrical Low Pressure Impactor (ELPI) and in the size range of 3?50 nm (mobility diameter) by Scanning Mobility Particle Sizer (SMPS), total number concentration of particles larger than 3 nm detected by an ultrafine condensation particle counter (UCPC), temperature, relative humidity, wind speed and direction, driving route of the mobile laboratory, and traffic density on the studied road. In this study, we have compared measured concentration data with the predictions of the road network dispersion model CAR-FMI used in combination with an aerosol process model MONO32. The vehicular exhaust emissions, and atmospheric dispersion and transformation of fine and ultrafine particles was evaluated within the distance scale of 200 m (corresponding to a time scale of a couple of minutes). We computed the temporal evolution of the number concentrations, size distributions and chemical compositions of various particle size classes. The atmospheric dilution rate of particles is obtained from the roadside dispersion model CAR-FMI. Considering the evolution of total number concentration, dilution was shown to be the most important process. The influence of coagulation and condensation on the number concentrations of particle size modes was found to be negligible at this distance scale. Condensation was found to affect the evolution of particle diameter in the two smallest particle modes. The assumed value of the concentration of condensable organic vapour of 1012 molecules cm?3 was shown to be in a disagreement with the measured particle size evolution, while the modelling runs with the concentration of condensable organic vapour of 109?1010 molecules cm?3 resulted in particle sizes that were closest to the measured values

Evaluation and modelling of the size fractionated aerosol particle number concentration measurements nearby a major road in Helsinki ? Part I: Modelling results within the LIPIKA project

International audienceA field measurement campaign was conducted near a major road "Itäväylä" in an urban area in Helsinki in 17?20 February 2003. Aerosol measurements were conducted using a mobile laboratory "Sniffer" at various distances from the road, and at an urban background location. Measurements included particle size distribution in the size range of 7 nm?10 ?m (aerodynamic diameter) by the Electrical Low Pressure Impactor (ELPI) and in the size range of 3?50 nm (mobility diameter) by Scanning Mobility Particle Sizer (SMPS), total number concentration of particles larger than 3 nm detected by an ultrafine condensation particle counter (UCPC), temperature, relative humidity, wind speed and direction, driving route of the mobile laboratory, and traffic density on the studied road. In this study, we have compared measured concentration data with the predictions of the road network dispersion model CAR-FMI used in combination with an aerosol process model MONO32. For model comparison purposes, one of the cases was additionally computed using the aerosol process model UHMA, combined with the CAR-FMI model. The vehicular exhaust emissions, and atmospheric dispersion and transformation of fine and ultrafine particles was evaluated within the distance scale of 200 m (corresponding to a time scale of a couple of minutes). We computed the temporal evolution of the number concentrations, size distributions and chemical compositions of various particle size classes. The atmospheric dilution rate of particles is obtained from the roadside dispersion model CAR-FMI. Considering the evolution of total number concentration, dilution was shown to be the most important process. The influence of coagulation and condensation on the number concentrations of particle size modes was found to be negligible on this distance scale. Condensation was found to affect the evolution of particle diameter in the two smallest particle modes. The assumed value of the concentration of condensable organic vapour of 1012 molecules cm?3 was shown to be in a disagreement with the measured particle size evolution, while the modelling runs with the concentration of condensable organic vapour of 109?1010 molecules cm?3 resulted in particle sizes that were closest to the measured values

Inter-year variation in pup production of Caspian seals (Pusa caspica) 2005-2012 determined from aerial surveys

Assessing species abundance and reproductive output is crucial for evaluations of population dynamics, conservation status and the development of management objectives. The Caspian seal (Pusa caspica) is a key predator in the Caspian Sea ecosystem and is listed as “Endangered” by IUCN. Here we report on fixed-wing aerial strip transect surveys of the breeding population on the Caspian Sea winter ice field carried out in February 2005-2012. Potential detection biases were estimated by applying a Petersen mark-recapture estimator to the counts from double photographic observations. We also tested for effects of weather conditions on count results, and for correlations between pup production and ice conditions and net primary productivity (npp). Fluctuations in pup production estimates were observed among years, ranging from 8,200 pups (95% CI 7,130-9342) in 2010 to 34,000 (95% CI 31,275-36,814) in 2005. Total adults on the ice ranged from 14,500 in 2010 to 66,300 in 2012. We did not detect significant associations between pup production and either ice summary data (ice season length, and ice area) or npp. The observed inter-year variation may be partly due to underlying biological drivers influencing the fecundity of the population, although measurement errors arising from observation bias, plus variation in survey timing and weather conditions may also have contributed. Identifying the potential drivers of Caspian seal population dynamics will require extending both the survey time series and the quality of supporting data. However, inter-year fluctuations should still cause concern that the population may be vulnerable to environmental variability and ecosystem dynamics

Identification of monogenic variants in more than ten per cent of children without type 1 diabetes-related autoantibodies at diagnosis in the Finnish Pediatric Diabetes Register

Peer reviewe

Life-history genotype explains variation in migration activity in Atlantic salmon (Salmo salar)

Peer reviewe

Circulating beta cell-specific CD8(+) T cells restricted by high-risk HLA class I molecules show antigen experience in children with and at risk of type 1 diabetes

In type 1 diabetes (T1D), autoreactive cytotoxic CD8(+) T cells are implicated in the destruction of insulin-producing beta cells. The HLA-B*3906 and HLA-A*2402 class I genes confer increased risk and promote early disease onset, suggesting that CD8(+) T cells that recognize peptides presented by these class I molecules on pancreatic beta cells play a pivotal role in the autoimmune response. We examined the frequency and phenotype of circulating preproinsulin (PPI)-specific and insulin B (InsB)-specific CD8(+) T cells in HLA-B*3906(+) children newly diagnosed with T1D and in high-risk HLA-A*2402(+) children before the appearance of disease-specific autoantibodies and before diagnosis of T1D. Antigen-specific CD8(+) T cells were detected using human leucocyte antigen (HLA) class I tetramers and flow cytometry was used to assess memory status. In HLA-B*3906(+) children with T1D, we observed an increase in PPI5-12-specific transitional memory CD8(+) T cells compared to non-diabetic, age- and HLA-matched subjects. Furthermore, PPI5-12-specific CD8(+) T cells in HLA-B*3906(+) children with T1D showed a significantly more antigen-experienced phenotype compared to polyclonal CD8(+) T cells. In longitudinal samples from high-risk HLA-A*2402(+) children, the percentage of terminal effector cells within the InsB(15-24)-specific CD8(+) T cells was increased before diagnosis relative to samples taken before the appearance of autoantibodies. This is the first study, to our knowledge, to report HLA-B*3906-restricted autoreactive CD8(+) T cells in T1D. Collectively, our results provide evidence that beta cell-reactive CD8(+) T cells restricted by disease-associated HLA class I molecules display an antigen-experienced phenotype and acquire enhanced effector function during the period leading to clinical diagnosis, implicating these cells in driving disease.Peer reviewe

Phylogenomic insights to the origin and spread of phocine distemper virus in European harbour seals in 1988 and 2002

The study was supported by the Villum Foundation, the Danish Ministry of the Environment, the Volkswagen Foundation (Az.: 89911) and the BONUS programme BaltHealth, which has received funding from BONUS (Art. 185), funded jointly by the EU, Innovation Fund Denmark (grants 6180-00001B and 6180-00002B), Forschungszentrum Jülich GmbH, German Federal Ministry of Education and Research (grant FKZ 03F0767A), Academy of Finland (grant 311966) and Swedish Foundation for Strategic Environmental Research (MISTRA).The 1988 and 2002 phocine distemper virus (PDV) outbreaks in European harbour seals Phoca vitulina are among the largest mass mortality events recorded in marine mammals. Despite its large impact on harbour seal population numbers, and 3 decades of studies, many questions regarding the spread and temporal origin of PDV remain unanswered. Here, we sequenced and analysed 7123 bp of the PDV genome, including the coding and non-coding regions of the entire P, M, F and H genes in tissues from 44 harbour seals to shed new light on the origin and spread of PDV in 1988 and 2002. The phylogenetic analyses trace the origin of the PDV strain causing the 1988 outbreak to between June 1987 and April 1988, while the origin of the strain causing the 2002 outbreak can be traced back to between July 2001 and April 2002. The analyses further point to several independent introductions of PDV in 1988, possibly linked to a southward mass immigration of harp seals in the winter and spring of 1987−1988. The vector for the 2002 outbreak is unknown, but the epidemiological analyses suggest the subsequent spread of PDV from the epicentre in the Kattegat, Denmark, to haul-out sites in the North Sea through several independent introductions.PostprintPeer reviewe

Trophic position and foraging ecology of Ross, Weddell, and crabeater seals revealed by compound-specific isotope analysis

Ross seals Ommatophoca rossii are one of the least studied marine mammals, with little known about their foraging ecology. Research to date using bulk stable isotope analysis suggests that Ross seals have a trophic position intermediate between that of Weddell Leptonychotes weddellii and crabeater Lobodon carcinophaga seals. However, consumer bulk stable isotope values not only reflect trophic dynamics, but also variations in baseline isotope values, which can be substantial. We used compound-specific isotope analysis of amino acids (CSI-AA) to separate isotopic effects of a shifting baseline versus trophic structure on the foraging ecology of these ecologically important Antarctic pinnipeds. We found that Ross seals forage in an open ocean food web, while crabeater and Weddell seals forage within similar food webs closer to shore. However, isotopic evidence suggests that crabeater seals are likely following sea ice, while Weddell seals target productive areas of the continental shelf of West Antarctica. Our CSI-AA data indicate that Ross seals have a high trophic position equivalent to that of Weddell seals, contrary to prior conclusions from nitrogen isotope results on bulk tissues. CSI-AA indicates that crabeater seals are at a trophic position lower than that of Ross and Weddell seals, consistent with a krill-dominated diet. Our results redefine the view of the trophic dynamics and foraging ecology of the Ross seal, and also highlight the importance of quantifying baseline isotope variations in foraging studies

Characterization of magnetic Czochralski silicon devices with aluminium oxide field insulator : effect of oxygen precursor on electrical properties and radiation hardness

Aluminium oxide (Al2O3) has been proposed as an alternative to thermal silicon dioxide (SiO2) as field insulator and surface passivation for silicon detectors, where it could substitute p-stop/p-spray insulation implants between pixels due to its negative oxide charge, and enable capacitive coupling of segments by means of its higher dielectric constant. Al2O3 is commonly grown by atomic layer deposition (ALD), which allows the deposition of thin layers with excellent precision. In this work, we report the electrical characterization of single pad detectors (diodes) and MOS capacitors fabricated on magnetic Czochralski silicon substrates and using Al2O3 as field insulator. Devices are studied by capacitance-voltage, current-voltage, and transient current technique measurements. We evaluate the influence of the oxygen precursors in the ALD process, as well as the effect of gamma irradiation, on the properties of these devices. We observe that leakage currents in diodes before the onset of breakdown are low for all studied ALD processes. Charge collection as measured by transient current technique (TCT) is also independent of the choice of oxygen precursor. The Al2O3 films deposited with O-3 possess a higher negative oxide charge than films deposited by H2O, However, in diodes a higher oxide charge is linked to earlier breakdown, as has been predicted by simulation studies. A combination of H2O and O-3 precursors results in a good compromise between the beneficial properties provided by the respective individual precursors.Peer reviewe