188 research outputs found

    Evaluation of greenhouse gas emissions and area of organic soils in cropland and grassland in Latvia – integrated National forest inventory data and soil maps approach

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    ArticleThe aim of the research was to assess distribution of organic soils in farmlands for the time period between 1990 and 2015, as well as to carry out a recalculation of GHG emissions from organic soils in grassland and cropland. We evaluated the area of typical organic soils using digitized soil maps created between 1960s and 1980s there were 183,000 ha of cropland and grassland on organic soils. A selected number of areas on organic soils intersecting with the National forest inventory (NFI) plots were surveyed. We found that 66 ± 10% of surveyed plots still conforms to criteria for organic soils according to Intergovernmental Panel on Climate Change (IPCC) guidelines; in the rest of plots soil organic matter has been mineralized and these areas do not conform to IPCC criteria of organic soils. The following distributionof organic soils was estimated in cropland – 6.3 ± 3.3% in 1990 and 4.1 ± 3.4% in 2015, but in grassland – 11.6 ± 3.6% in 1990 and 7.7 ± 3.9% in 2015. The annual reduction of GHG emissions due to reduction of area of organic soils in cropland in 2015 corresponds to 1,400,000 tonnes CO2 eq. in comparison to 1990 and in grassland – to 1,100,000 tonnes CO2 eq. The estimated reduction of the GHG emissions due to conversion of organic soils into mineral soils, comparing the average value in 2005–2009 with the projection for 2021–2030 on average will correspond to 313,000 tonnes CO2 eq. annually, however LULUCF sector still won’t become a net CO2 sink according to the GHG inventory data on other land use categories and carbon pools

    Shear band dynamics from a mesoscopic modeling of plasticity

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    The ubiquitous appearance of regions of localized deformation (shear bands) in different kinds of disordered materials under shear is studied in the context of a mesoscopic model of plasticity. The model may or may not include relaxational (aging) effects. In the absence of relaxational effects the model displays a monotonously increasing dependence of stress on strain-rate, and stationary shear bands do not occur. However, in start up experiments transient (although long lived) shear bands occur, that widen without bound in time. I investigate this transient effect in detail, reproducing and explaining a t^1/2 law for the thickness increase of the shear band that has been obtained in atomistic numerical simulations. Relaxation produces a negative sloped region in the stress vs. strain-rate curve that stabilizes the formation of shear bands of a well defined width, which is a function of strain-rate. Simulations at very low strain-rates reveal a non-trivial stick-slip dynamics of very thin shear bands that has relevance in the study of seismic phenomena. In addition, other non-stationary processes, such as stop-and-go, or strain-rate inversion situations display a phenomenology that matches very well the results of recent experimental studies.Comment: 10 pages, 10 figure

    Participative Facility Planning for Obstetrical and Neonatal Care Processes: Beginning of Life Process

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    Introduction. Old hospitals may promote inefficient patient care processes and safety. A new, functionally planned hospital presents a chance to create an environment that supports streamlined, patient-centered healthcare processes and adapts to users' needs. This study depicts the phases of a facility planning project for pregnant women and newborn care processes (beginning of life process) at Turku University Hospital. Materials and Methods. Project design reports and meeting documents were utilized to assess the beginning of life process as well as the work processes of the Women's and Children's Hospital. Results. The main elements of the facility design (FD) project included rigorous preparation for the FD phase, functional planning throughout the FD process, and setting key values: (1) family-centered care, (2) Lean thinking and Lean tools as the framework for the FD process, (3) safety, and (4) cooperation. Conclusions. A well-prepared FD project with sufficient insight into functional planning, Lean thinking, and user-centricity seemed to facilitate the actual FD process. Although challenges occurred, the key values were not forgone and were successfully incorporated into the new hospital building

    Arctic air pollution: Challenges and opportunities for the next decade

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    The Arctic is a sentinel of global change. This region is influenced by multiple physical and socio-economic drivers and feedbacks, impacting both the natural and human environment. Air pollution is one such driver that impacts Arctic climate change, ecosystems and health but significant uncertainties still surround quantification of these effects. Arctic air pollution includes harmful trace gases (e.g. tropospheric ozone) and particles (e.g. black carbon, sulphate) and toxic substances (e.g. polycyclic aromatic hydrocarbons) that can be transported to the Arctic from emission sources located far outside the region, or emitted within the Arctic from activities including shipping, power production, and other industrial activities. This paper qualitatively summarizes the complex science issues motivating the creation of a new international initiative, PACES (air Pollution in the Arctic: Climate, Environment and Societies). Approaches for coordinated, international and interdisciplinary research on this topic are described with the goal to improve predictive capability via new understanding about sources, processes, feedbacks and impacts of Arctic air pollution. Overarching research actions are outlined, in which we describe our recommendations for 1) the development of trans-disciplinary approaches combining social and economic research with investigation of the chemical and physical aspects of Arctic air pollution; 2) increasing the quality and quantity of observations in the Arctic using long-term monitoring and intensive field studies, both at the surface and throughout the troposphere; and 3) developing improved predictive capability across a range of spatial and temporal scales

    Late-spring and summertime tropospheric ozone and NO2 in western Siberia and the Russian Arctic : regional model evaluation and sensitivities

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    We use a regional chemistry transport model (Weather Research and Forecasting model coupled with chemistry, WRF-Chem) in conjunction with surface observations of tropospheric ozone and Ozone Monitoring Instrument (OMI) satellite retrievals of tropospheric column NO2 to evaluate processes controlling the regional distribution of tropospheric ozone over western Siberia for late spring and summer in 2011. This region hosts a range of anthropogenic and natural ozone precursor sources, and it serves as a gateway for near-surface transport of Eurasian pollution to the Arctic. However, there is a severe lack of in situ observations to constrain tropospheric ozone sources and sinks in the region. We show widespread negative bias in WRF-Chem tropospheric column NO2 when compared to OMI satellite observations from May-August, which is reduced when using ECLIPSE (Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants) v5a emissions (fractional mean bias (FMB) = -0.82 to -0.73) compared with the EDGAR (Emissions Database for Global Atmospheric Research)-HTAP (Hemispheric Transport of Air Pollution) v2.2 emissions data (FMB = -0.80 to -0.70). Despite the large negative bias, the spatial correlations between model and observed NO2 columns suggest that the spatial pattern of NOx sources in the region is well represented. Scaling trans-port and energy emissions in the ECLIPSE v5a inventory by a factor of 2 reduces column NO2 bias (FMB = -0.66 to -0.35), but with overestimates in some urban regions and little change to a persistent underestimate in background regions. Based on the scaled ECLIPSE v5a emissions, we assess the influence of the two dominant anthropogenic emission sectors (transport and energy) and vegetation fires on surface NOx and ozone over Siberia and the Russian Arctic. Our results suggest regional ozone is more sensitive to anthropogenic emissions, particularly from the transport sector, and the contribution from fire emissions maximises in June and is largely confined to latitudes south of 60 degrees N. Ozone dry deposition fluxes from the model simulations show that the dominant ozone dry deposition sink in the region is to forest vegetation, averaging 8.0 Tg of ozone per month, peaking at 10.3 Tg of ozone deposition during June. The impact of fires on ozone dry deposition within the domain is small compared to anthropogenic emissions and is negligible north of 60 degrees N. Overall, our results suggest that surface ozone in the region is controlled by an interplay between seasonality in atmospheric transport patterns, vegetation dry deposition, and a dominance of transport and energy sector emissions.Peer reviewe

    Identifying Criegee intermediates as potential oxidants in the troposphere

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    Abstract and poster presented at the AGU Fall meeting, San Francisco 2015.Criegee intermediates (CI) are formed during the ozonolysis of unsaturated compounds and have been intensively studied in the last few years due to their possible role as oxidants in the troposphere. Stabilised CI (SCI) are now known to react very rapidly, k(298 K) = 10-12 to 10-10 cm3 molecule-1 s-1, with a large number of trace gases (SO2, NO2, organic acids, water dimers). Still, it remains challenging to assess their effective oxidative capacity, as CI chemistry is complex, spans a large range of rate coefficients for different SCI conformers reacting with water dimers and trace gases, and in addition no reliable measurement technique able to detect ambient SCI concentrations is currently available. In this study, we examine the extensive dataset from the HUMPPA-COPEC 2010 and the HOPE 2012 field campaigns, aided by literature data, to estimate the abundance of SCI in the lower troposphere. The budget of SCI is analyzed using four different approaches: 1) based on an observed yet unexplained H2SO4 production; 2) from the measured concentrations of unsaturated volatile organic compounds (VOC); 3) from OH reactivity measurements; 4) from the unexplained production rate of OH. A SCI concentration range between 5 x 103 and 2 x 106 molecule cm-3 is calculated for the two environments. The central weighted estimate of the SCI concentration over the boreal forest of ~ 5 x 104 molecules cm-3 implies a significant impact on the conversion of SO2 into H2SO4. In addition, we present measurements obtained using our inlet pre-injector laser-induced fluorescence assay by gas expansion technique (IPI-LIF-FAGE) for the above-mentioned campaigns. A recent laboratory study performed with the same instrumental setup showed that the IPI-LIF-FAGE system is sensitive to the detection of the OH formed from unimolecular decomposition of SCI. Building on these measurements, the background OH (OHbg) measured during the two field campaigns is investigated in comparison with many other trace gases to assess if the observations in controlled conditions are transferable to ambient conditions

    Identifying Criegee intermediates as potential oxidants in the troposphere

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    Discussion started 24/10/16We analysed the extensive dataset from the HUMPPA-COPEC 2010 and the HOPE 2012 field campaigns in the boreal forest and rural environments of Finland and Germany, respectively, and estimated the abundance of stabilised Criegee intermediates (SCI) in the lower troposphere. Based on laboratory tests, we propose that the background OH signal observed in our IPI-LIF-FAGE instrument during the afore-mentioned campaigns is caused at least partially by SCI. This hypothesis is based on observed correlations with temperature and with concentrations of unsaturated volatile organic compounds and ozone. The background OH concentration also complements the previously underestimated production rate of sulfuric acid and is consistent with its scavenging through the addition of sulphur dioxide. A central estimate of the SCI concentration of ~ 5 × 104 molecules cm−3 (with an order of magnitude uncertainty) is calculated for the two environments. This implies a very low ambient concentration of SCI, though, over the boreal forest, significant for the conversion of SO2 into H2SO4. The large uncertainties in these calculations, owing to the many unknowns in the chemistry of Criegee intermediates, emphasise the need to better understand these processes and their potential effect on the self-cleaning capacity of the atmosphere

    Cell surface delivery and structural re-organization by pharmacological chaperones of an oligomerization-defective α1b-adrenoceptor mutant demonstrates membrane targeting of GPCR oligomers

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    Many G-protein-coupled receptors, including the α1b-adrenoceptor, form homo-dimers or oligomers. Mutation of hydrophobic residues in transmembrane domains I and IV alters the organization of the α1b-adrenoceptor oligomer, with transmembrane domain IV playing a critical role. These mutations also result in endoplasmic reticulum trapping of the receptor. Following stable expression of this α1b-adrenoceptor mutant, cell surface delivery, receptor function and structural organization were recovered by treatment with a range of α1b-adrenoceptor antagonists that acted at the level of the endoplasmic reticulum. This was accompanied by maturation of the mutant receptor to a terminally N-glycosylated form, and only this mature form was trafficked to the cell surface. Co-expression of the mutant receptor with an otherwise wild-type form of the α1b-adrenoceptor that is unable to bind ligands resulted in this wild-type variant also being retained in the endoplasmic reticulum. Ligand-induced cell surface delivery of the mutant α1b-adrenoceptor now allowed co-recovery to the plasma membrane of the ligand-binding-deficient mutant. These results demonstrate that interactions between α1b-adrenoceptor monomers occur at an early stage in protein synthesis, that ligands of the α1b-adrenoceptor can act as pharmacological chaperones to allow a structurally compromised form of the receptor to pass cellular quality control, that the mutated receptor is not inherently deficient in function and that an oligomeric assembly of ligand-binding-competent and -incompetent forms of the α1b-adrenoceptor can be trafficked to the cell surface by binding of a ligand to only one component of the receptor oligomer
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