Analysis of ambient SO2 concentrations and winds in the complex surroundings of a thermal power plant

SO2 pollution is still a significant problem in Slovenia, especially around large thermal power plants (TPPs), like the one at ˇSoˇstanj. The ˇSoˇstanj TPP is the exclusive source of SO2 in the area and is therefore a perfect example for air pollution studies. In order to understand air pollution around the ˇSoˇstanj TPP in detail, some analyses of emissions and ambient concentrations of SO2 at six automated monitoring stations in the surroundings of the TPP were made. The data base from 1991 to 1993 was used when there were no desulfurisation plants in operation. Statistical analyses of the influence of the emissions from the three TPP stacks at different measuring points were made. The analyses prove that the smallest stack (100 m) mainly pollutes villages and towns near the TPP within a radius of a few kilometres. The medium stack’s (150 m) influence is noticed at shorter as well as at longer distances up to more than ten kilometres. The highest stack (230 m) pollutes mainly at longer distances, where the plume reaches the higher hills. Detailed analyses of ambient SO2 concentrations were made. They show the temporal and spatial distribution of different classes of SO2 concentrations from very low to alarming values. These analyses show that pollution patterns at a particular station remain the same if observed on a yearly basis, but can vary very much if observed on a monthly basis, mainly because of different weather patterns. Therefore the winds in the basin (as the most important feature influencing air pollution dispersion) were further analysed in detail to find clusters of similar patterns. For cluster analysis of ground-level winds patterns in the basin around the ˇSoˇstanj Thermal Power Plant, the Kohonen neural network and Leaders’ method were used. Furthermore, the dependence of ambient SO2 concentrations on the clusters obtained was analysed. The results proved that effective cluster analysis can be a useful tool for compressing a huge wind data base in order to find the correlation between winds and pollutant concentrations. The analyses made provide a better insight into air pollution over complex terrain

Ozone prediction based on neural networks and Gaussian processes

The urban environment in Slovenia is confronted with the air pollution problem of harmfully high ozone concentrations. In the last two decades the automatic ozone measuring network was extended and now covers regions where the highest values are expected. Due to topographical and climatological conditions and the presence of extensive urban environments, the most critical locations are the ones in the western part of Slovenia. In the city of Nova Gorica a modern automatic urban air pollution measuring station was installed. Measurements at this station clearly showed that ozone is a considerable pollutant there, especially in the summer time. In this work a perceptron neural-network–based model and a Gaussian-process–based model for ozone concentration forecasting for the city of Nova Gorica was developed and evaluated. The methods of feature determination and pattern selection for the model training process are delineated. The shortcomings of the models and possibilities for improvements are discussed with respect to evaluation of the effectiveness of the methods

Observational Characterization of the Downward Atmospheric Longwave Radiation at the Surface in the City of São Paulo

This work describes the seasonal and diurnal variations of downward longwave atmospheric irradiance (LW) at the surface in São Paulo, Brazil, using 5-min-averaged values of LW, air temperature, relative humidity, and solar radiation observed continuously and simultaneously from 1997 to 2006 on a micrometeorological platform, located at the top of a 4-story building. An objective procedure, including 2-step filtering and dome emission effect correction, was used to evaluate the quality of the 9-yr-long LW dataset. The comparison between LW values observed and yielded by the Surface Radiation Budget project shows spatial and temporal agreement, indicating that monthly and annual average values of LW observed in one point of São Paulo can be used as representative of the entire metropolitan region of São Paulo. The maximum monthly averaged value of the LW is observed during summer (389 ± 14 W m-2; January), and the minimum is observed during winter (332 ± 12 W m-2; July). The effective emissivity follows the LW and shows a maximum in summer (0.907 ± 0.032; January) and a minimum in winter (0.818 ± 0.029; June). The mean cloud effect, identified objectively by comparing the monthly averaged values of the LW during clear-sky days and all-sky conditions, intensified the monthly average LW by about 32.0 ± 3.5 W m-2 and the atmospheric effective emissivity by about 0.088 ± 0.024. In August, the driest month of the year in São Paulo, the diurnal evolution of the LW shows a minimum (325 ± 11 W m-2) at 0900 LT and a maximum (345 ± 12 W m-2) at 1800 LT, which lags behind (by 4 h) the maximum diurnal variation of the screen temperature. The diurnal evolution of effective emissivity shows a minimum (0.781 ± 0.027) during daytime and a maximum (0.842 ± 0.030) during nighttime. The diurnal evolution of all-sky condition and clear-sky day differences in the effective emissivity remain relatively constant (7% ± 1%), indicating that clouds do not change the emissivity diurnal pattern. The relationship between effective emissivity and screen air temperature and between effective emissivity and water vapor is complex. During the night, when the planetary boundary layer is shallower, the effective emissivity can be estimated by screen parameters. During the day, the relationship between effective emissivity and screen parameters varies from place to place and depends on the planetary boundary layer process. Because the empirical expressions do not contain enough information about the diurnal variation of the vertical stratification of air temperature and moisture in São Paulo, they are likely to fail in reproducing the diurnal variation of the surface emissivity. The most accurate way to estimate the LW for clear-sky conditions in São Paulo is to use an expression derived from a purely empirical approach

Re-evaluation of the Lagrangian particle modelling system on an experimental campaign in complex terrain

Slovenian legislation for industrial air pollution control requires efficient modelling systems for small domains over complex topography. To determine the performance and efficiency of the Lagrangian particle modelling system used for this purpose a study was made where a general purpose modelling system designed for local-scale areas was used. The main goal of the study was to evaluate a modelling system of this kind using an operational configuration of both input data and model parameters, choosing a testing period with very complex dispersion conditions. This severe check could help to better understand the general quality that a model can achieve in these conditions giving some idea on how to better evaluate and use some results that seem to be very negative simply looking at some statistical parameter. Data from a three-week experimental campaign performed around the ˇSoˇstanj thermal power plant during the spring of 1991 was used (analyzed) for evaluation. The database covers very high ambient concentrations (due to the absence of desulphurisation plants) over complex terrain. The simulation was performed for the full duration of the campaign and a particular situation during the 1st and the 2nd of April 1991 was used as an example to outline the model behaviour in complex conditions. During this selected sub-period measurements revealed that (measured) wind speeds were very low, wind changed course in all directions rapidly and consequently the plume spread in all directions. A comparison between measured and reconstructed SO2 concentrations was made at the positions of several automatic air quality measuring stations located around the thermal power plant. Standard statistical indexes to evaluate model performances are instead computed at the same positions for the entire period of the experimental campaign. Overall the reconstructed SO2 concentrations were underestimated relative to the measured ones, but all direct air pollution events were reconstructed. Some weaknesses of the model in the correct reconstruction of peak events are explained and a way to better describe them and to enhance statistical indexes is proposed

Zika virus impairs the development of blood vessels in a mouse model of congenital infection

Zika virus (ZIKV) is associated with brain development abnormalities such as primary microcephaly, a severe reduction in brain growth. Here we demonstrated in vivo the impact of congenital ZIKV infection in blood vessel development, a crucial step in organogenesis. ZIKV was injected intravenously in the pregnant type 2 interferon (IFN)-deficient mouse at embryonic day (E) 12.5. The embryos were collected at E15.5 and postnatal day (P)2. Immunohistochemistry for cortical progenitors and neuronal markers at E15.5 showed the reduction of both populations as a result of ZIKV infection. Using confocal 3D imaging, we found that ZIKV infected brain sections displayed a reduction in the vasculature density and vessel branching compared to mocks at E15.5; altogether, cortical vessels presented a comparatively immature pattern in the infected tissue. These impaired vascular patterns were also apparent in the placenta and retina. Moreover, proteomic analysis has shown that angiogenesis proteins are deregulated in the infected brains compared to controls. At P2, the cortical size and brain weight were reduced in comparison to mock-infected animals. In sum, our results indicate that ZIKV impairs angiogenesis in addition to neurogenesis during development. The vasculature defects represent a limitation for general brain growth but also could regulate neurogenesis directly

Association study of candidate DNA-repair gene variants and acute graft versus host disease in pediatric patients receiving allogeneic hematopoietic stem-cell transplantation

Acute Graft versus Host Disease (aGvHD) grades 2-4 occurs in 15-60% of pediatric patients undergoing allogeneic haematopoietic stem-cell transplantation (allo-HSCT). The collateral damage to normal tissue by conditioning regimens administered prior to allo-HSCT serve as an initial trigger for aGvHD. DNA-repair mechanisms may play an important role in mitigating this initial damage, and so the variants in corresponding DNA-repair protein-coding genes via affecting their quantity and/or function. We explored 51 variants within 17 DNA-repair genes for their association with aGvHD grades 2-4 in 60 pediatric patients. The cumulative incidence of aGvHD 2-4 was 12% (n = 7) in the exploratory cohort. MGMT rs10764881 (G>A) and EXO rs9350 (c.2270C>T) variants were associated with aGvHD 2-4 [Odds ratios = 14.8 (0 events out of 40 in rs10764881 GG group) and 11.5 (95% CI: 2.3-191.8), respectively, multiple testing corrected p A) remained significant (adjusted HR = 2.05 [95% CI: 1.06-3.94]; p = 0.03) in the presence of other clinical risk factors. Higher MGMT expression was seen in GG carriers for rs10764881 and was associated with higher IC50 of Busulfan in lymphoblastoid cells. MGMT rs10764881 carrier status could predict aGvHD occurrence in pediatric patients undergoing allo-HSCT.Transplantation and immunomodulatio

Precarious education-to-work transitions: entering welfare professions under a workfarist regime

This article looks at the process of education-to-work transitions in female-dominated welfare professions within the Slovenian post-crisis context marked by a workfarist agenda. It departs from a scholarship that conceptualises precarity as a transitional vulnerability and disaffiliation exacerbated by workfarist policies to explore the contemporary experience of those trying to achieve professional integration under a volatile workfarist regime. The findings reveal a mismatch between established regulations for early career recruitment and professional licensing and the actual chances on the labour market to meet these requirements through available workfarist non-standard entry-level jobs/schemes designed for particular status and/or socio-demographic groups. It gives new evidence that European workfare regimes exacerbate precarity and a novel understanding of state-manufactured precarization as an intersectional process of marginalization and discrimination that not only hinders integration into welfare professions, but also downloads the costs of social reproduction on the next generation, causes precarious aging and widens intersectional differences

Prophylactic Embolization of the Cystic Artery Before Radioembolization: Feasibility, Safety, and Outcomes

PurposeTo evaluate the safety and efficacy of two different methods of proximal cystic artery embolization in patients undergoing yttrium-90 radioembolization.Materials and methodsForty-six patients had cystic artery embolization performed immediately before yttrium-90 radioembolization, either by using Gelfoam pledgets (n = 35) or coils (n = 11). Clinical symptomatology during the admission and angiographic findings at 1-month follow-up were retrospectively reviewed. Rates of collateralization or recanalization of the cystic artery were compared, as well as the frequency of postprocedural abdominal pain and need for cholecystectomy.ResultsTechnical success was achieved in all patients, and there were no procedural complications related to cystic artery embolization. Of the 11 coil-embolized patients, 5 (45%) demonstrated collateralization of the cystic artery at 1 month, and 1 (9%) demonstrated recanalization of the cystic artery. Of the 35 Gelfoam-embolized cases, 2 (6%) had collateralized at 1 month, and 14 (40%) had recanalized. Two patients (one from each group) had self-limited right upper quadrant pain after the procedure, and one patient in the coil embolization group required cholecystectomy.ConclusionProximal cystic artery embolization is safe and feasible and may be performed during liver-directed embolotherapy to minimize the exposure of the gallbladder to particulate, chemoembolic, or radioembolic agents