| 1. |
- Omstedt, Anders, 1949, et al.
(författare)
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Future changes in the Baltic Sea acid-base (pH) and oxygen balances
- 2012
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Ingår i: Tellus. Series B, Chemical and physical meteorology. - : Stockholm University Press. - 0280-6509 .- 1600-0889. ; 64
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Tidskriftsartikel (refereegranskat)abstract
- Possible future changes in Baltic Sea acid–base (pH) and oxygen balances were studied using a catchment–sea coupled model system and numerical experiments based on meteorological and hydrological forcing datasets and scenarios. By using objective statistical methods, climate runs for present climate conditions were examined and evaluated using Baltic Sea modelling. The results indicate that increased nutrient loads will not inhibit future Baltic Sea acidification; instead, the seasonal pH cycle will be amplified by increased biological production and mineralization. All examined scenarios indicate future acidification of the whole Baltic Sea that is insensitive to the chosen global climate model. The main factor controlling the direction and magnitude of future pH changes is atmospheric CO2 concentration (i.e. emissions). Climate change and land-derived changes (e.g. nutrient loads) affect acidification mainly by altering the seasonal cycle and deep-water conditions. Apart from decreasing pH, we also project a decreased saturation state of calcium carbonate, decreased respiration index, and increasing hypoxic area – all factors that will threaten the marine ecosystem. We demonstrate that substantial reductions in fossil-fuel burning are needed to minimize the coming pH decrease and substantial reductions in nutrient loads are needed to reduce the coming increase in hypoxic and anoxic waters.
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| 2. |
- Hong, Bongghi, et al.
(författare)
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Evaluating regional variation of net anthropogenic nitrogen and phosphorus inputs (NANI/NAPI), major drivers, nutrient retention pattern and management implications in the multinational areas of Baltic Sea basin
- 2012
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Ingår i: Ecological Modelling. - : Elsevier BV. - 0304-3800 .- 1872-7026. ; 227, s. 117-135
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Tidskriftsartikel (refereegranskat)abstract
- The NANI/NAPI (net anthropogenic nitrogen/phosphorus input) Calculator Toolbox described in this paper is designed to address the consequences to Baltic Sea nutrient loads of the significant variation in agronomic practices and dietary preferences among European countries whose watersheds comprise the Baltic Sea basin. A primary objective of this work is to develop regional parameters and datasets for this budgeting tool. A previous version of the toolbox was applied to the entire contiguous United States to calculate NANI and its components (atmospheric N deposition, fertilizer N application, agricultural N fixation and N in net food and feed imports). Here, it is modified for application to the Baltic Sea catchments, where coastal watersheds from several countries are draining to international waters. A similar accounting approach is taken for calculating NAPI, which includes fertilizer P application, P in net food and feed imports and non-food use of P by human. Regional variation of NANI/NAPI parameters (agricultural fixation rates, human intake rates and livestock intake and excretion rates) are estimated, and their impact on the regional nutrient budget and the riverine nutrient flux is evaluated. There is a distinct north-to-south gradient in NANI and NAPI across the Baltic Sea catchments, and regional nutrient inputs are strongly related to riverine nutrient fluxes. Analysis of regional nutrient retention pattern indicates that, for some countries, compliance to the Baltic Sea Action Plan would imply enormous changes in the agricultural sector.
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| 3. |
- Hong, Bongghi, et al.
(författare)
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NANI/NAPI Calculator Toolbox Version 2.0 Documentation : Net Anthropogenic Nutrient Inputs in Baltic Sea Catchments
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The main objective of this work was to develop regional settings of the NANI budgeting tool that will address the significant variation in agricultural practices and resulting nutrient accountings among European countries. NANI (Net Anthropogenic Nitrogen Inputs), first introduced by Howarth et al. (1996), estimate the human‐induced nitrogen inputs to a watershed and have been shown to be a good predictor of riverine nitrogen export at a large scale, multi‐year average basis. NANI have been calculated as the sum of four major components: atmospheric N deposition, fertilizer N application, agricultural N fixation, and net food and feed imports, which in turn are composed of crop and animal N production (negative fluxes removing N from watersheds) and animal and human N consumption (positive fluxes adding N to watersheds). Assuming approximate steady-state behavior, riverine N export is a fixed proportion of net nitrogen inputs.Similar calculations can be made for phosphorus (P) inputs, though because atmospheric deposition of P is usually considered negligible and there is no analog in P for atmospheric fixation, the calculation of Net Anthropogenic Phosphorus Inputs (NAPI) reduces to accounting for P fertilizer and P in net food/feed terms. While this document is primarily concerned with calculating NANI, we also describe the data sources and assumptions used to make the parallel calculations of NAPI.Version 2.0 of the Toolbox described in this document is an improvement of version 1.0 developed for US watersheds (http://www.eeb.cornell.edu/biogeo/nanc/nani/nani.htm; Hong et al. 2011). Version 1.0 allows the user to calculate NANI in any area within the contiguous United States (e.g., watershed, county, etc.) from nationally available databases downloadable from the Internet. The toolbox consists of a set of tools that:(1) calculate the proportions of various regions (political or gridded) in which data are collected that fall into areas of interest such as watersheds (“NANI‐GIS tools”),(2) extract and organize relevant data downloaded from web‐based datasets to be used by the accounting tools (“NANI‐extraction tools”), and(3) calculate NANI, their components, and other relevant items such as animal excretion (“NANI-.‐accounting tools”).While attempting to apply version 1.0 of the toolbox to Baltic Sea catchments, we found that the calculation of NANI in Baltic Sea catchments is more challenging than in US watersheds, mainly for two reasons:• Watersheds span international boundaries. Significant variation in agricultural practices and resulting nutrient accountings among European countries exist. For example, a substantial gradient in agricultural practices is expected among the former EU countries, new EU member states with transitional economies, and Belarus and Russia.• Gaps and uncertainties in the available data are much greater than those in the US. In general, the problem of missing information is more severe for the transitional countries, Belarus, and Russia, requiring numerous assumptions and guesswork to be made to deal with the insufficient data issue.Version 2.0 of the Toolbox describe in this document has several modules and improvements added to version 1.0 (which assumes spatially uniform agricultural practices, i.e., fixed values for all the NANI parameters, supported by the availability of well‐established and standardized datasets) to address the above difficulties. These improvements include:• Allowing spatial variation of NANI parameters (in this example, country‐specific NANI parameters) (Sections 4, 5.1, and 5.2)• Distribution of regional data (e.g., country-level crop production) into smaller spatial units (e.g., grid cells containing crop area information) (Section 5.3)• Making post‐calculation adjustments and refinements by accepting auxiliary datasets and manual calculations from the user (Section 3) In the following sections we describe the calculation of NANI and their components in the Baltic Sea catchments, with details of data availability, input preparation, and step-by‐step procedure of the use of various tools, and provide some preliminary results. In addition, Appendix 1 described parameter values used to create NAPI estimates following an accounting methodology in parallel to that for NANI.
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| 4. |
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| 5. |
- Stalnacke, P., et al.
(författare)
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Nitrogen surface water retention in the Baltic Sea drainage basin
- 2015
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Ingår i: Hydrology and Earth System Sciences. - : Copernicus GmbH. - 1027-5606 .- 1607-7938. ; 19:2, s. 981-996
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we estimate the surface water retention of nitrogen (N) in all the 117 drainage basins to the Baltic Sea with the use of a statistical model (MESAW) for source apportionment of riverine loads of pollutants. Our results show that the MESAW model was able to estimate the N load at the river mouth of 88 Baltic Sea rivers, for which we had observed data, with a sufficient degree of precision and accuracy. The estimated retention parameters were also statistically significant. Our results show that around 380 000 t of N are annually retained in surface waters draining to the Baltic Sea. The total annual riverine load from the 117 basins to the Baltic Sea was estimated at 570 000 t of N, giving a total surface water N retention of around 40 %. In terms of absolute retention values, three major river basins account for 50% of the total retention in the 117 basins; i.e. around 104 000 t of N are retained in Neva, 55 000 t in Vistula and 32 000 t in Oder. The largest retention was found in river basins with a high percentage of lakes as indicated by a strong relationship between N retention (%) and share of lake area in the river drainage areas. For example in Gota alv, we estimated a total N retention of 72 %, whereof 67% of the retention occurred in the lakes of that drainage area (Lake Vanern primarily). The obtained results will hopefully enable the Helsinki Commission (HELCOM) to refine the nutrient load targets in the Baltic Sea Action Plan (BSAP), as well as to better identify cost-efficient measures to reduce nutrient loadings to the Baltic Sea.
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| 6. |
- Hägg, Linus, et al.
(författare)
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Estimating the neutron yield in a deuterium plasma with the JET neutron camera
- 2023
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Ingår i: Review of Scientific Instruments. - : American Institute of Physics (AIP). - 0034-6748 .- 1089-7623. ; 94:7
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Tidskriftsartikel (refereegranskat)abstract
- The JET neutron camera is a well-established detector system at JET, which has 19 sightlines each equipped with a liquid scintillator. The system measures a 2D profile of the neutron emission from the plasma. A first principle physics method is used to estimate the DD neutron yield that is based on JET neutron camera measurements and is independent of other neutron measurements. This paper details the data reduction techniques, models of the neutron camera, simulations of neutron transport, and detector responses used to this end. The estimate uses a simple parameterized model of the neutron emission profile. The method makes use of the JET neutron camera’s upgraded data acquisition system. It also accounts for neutron scattering near the detectors and transmission through the collimator. These components together contribute to 9% of the detected neutron rate above a 0.5 MeVee energy threshold. Despite the simplicity of the neutron emission profile model, the DD neutron yield estimate falls on average within 10% agreement with a corresponding estimate from the JET fission chambers. The method can be improved by considering more advanced neutron emission profiles. It can also be expanded to estimate the DT neutron yield with the same methodology.
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| 7. |
- Marcinkevicius, Benjaminas, et al.
(författare)
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Fuel ion ratio determination using the 14 MeV Tandem neutron spectrometer for JET DTE1 campaign discharges
- 2022
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Ingår i: Fusion engineering and design. - : Elsevier. - 0920-3796 .- 1873-7196. ; 184
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Tidskriftsartikel (refereegranskat)abstract
- This paper investigates the determination of the fuel ion ratio nT/ntot in fusion experiments using two different approaches. The methods are applied to plasma discharges from the deuterium-tritium campaign at the Joint European Torus (JET) in 1997. Multiple discharges have been analysed using data acquired with the Tandem (KM2) neutron spectrometer, using a new neutron spectrometer response function and improved line-of-sight information.The two different approaches were generally similar with the exception of the beam slowing down modelling, handled by two different particle transport codes, namely, TRANSP and PENCIL.The results show that nT/ntot can be determined using Tandem neutron spectrometer data; nT/ntot using both of the approaches are consistent and within the uncertainty for a range of studied discharges.The obtained results support previous studies on nT/ntot determination using neutron spectroscopy. In addition, we have shown that PENCIL can be used instead of TRANSP for a range of discharges which could simplify and speed up the estimation of nT/ntot. The possible limitations of the approach using PENCIL could be investigated using different neutron spectrometer data from the 2021 JET deuterium-tritium campaign.A similar spectrometer like Tandem is planned to be operational at ITER and the results of this paper form the first experimental verification of the capability for nT/ntot measurements with such spectrometers. Further research on this could lead to better understanding of these instruments and their limitations before the start of experiments at ITER.
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| 8. |
- Sjöström, Jonas, et al.
(författare)
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Designing Software for Web-based Psychosocial Care : Longitudinal Design Science Research in U-CARE
- 2024
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Ingår i: Communications of the Association for Information Systems. - 1529-3181. ; 54:45
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Tidskriftsartikel (refereegranskat)abstract
- This paper addresses the design of software for web-based psychosocial care – an increasing and highly relevant societal issue. The paper explores two primary research questions: 1) What design principles should guide the creation of web-based software for online psychological support, and 2) How can design science research facilitate the development and assessment of innovative eHealth solutions? Our research – a tailored DSR approach – was conducted over a 10+ year period within the multi-disciplinary research programme U-CARE. As information systems researchers, we worked as researchers and developers, in tight collaboration with psychologists, economists, medical doctors, nurses, and other key stakeholders. Through this process, we continually reflected and abstracted our experiences into design principles and DSR methodology. In response to the first research question, we introduce a set of design principles for web-based psychosocial support, shaped by the overarching LAME DSR approach. These principles include malleability for adaptability and sustainability, privacy and accountability in online environments, and a focus on stakeholder-specific functionalities like therapist dashboards and smooth authentication processes. In response to the second research question, we present the LAME DSR approach and an informed argument concerning its role in the establishment of a strategic, high-impact research environment.
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| 9. |
- Wållberg, Helena, et al.
(författare)
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HER2-Positive Tumors Imaged Within 1 Hour Using a Site-Specifically C-11-Labeled Sel-Tagged Affibody Molecule
- 2012
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Ingår i: Journal of Nuclear Medicine. - Stockholm : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 53:9, s. 1446-1453
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Tidskriftsartikel (refereegranskat)abstract
- A rapid, reliable method for distinguishing tumors or metastases that overexpress human epidermal growth factor receptor 2 (HER2) from those that do not is highly desired for individualizing therapy and predicting prognoses. In vivo imaging methods are available but not yet in clinical practice; new methodologies improving speed, sensitivity, and specificity are required. Methods: A HER2-binding Affibody molecule, Z(HER2:342), was recombinantly fused with a C-terminal selenocysteine-containing tetrapeptide Sel-tag, allowing site-specific labeling with either C-11 or Ga-68, followed by biodistribution studies with small-animal PET. Dosimetry data for the 2 radiotracers were compared. Imaging of HER2-expressing human tumor xenografts was performed using the C-11-labeled Affibody molecule. Results: Both the C-11- and Ga-68-labeled tracers initially cleared rapidly from the blood, followed by a slower decrease to 4-5 percentage injected dose per gram of tissue at 1 h. Final retention in the kidneys was much lower (>5-fold) for the C-11-labeled protein, and its overall absorbed dose was considerably lower. C-11-Z(HER2:342) showed excellent tumor-targeting capability, with almost 10 percentage injected dose per gram of tissue in HER2-expressing tumors within 1 h. Specificity was demonstrated by preblocking binding sites with excess ligand, yielding significantly reduced radiotracer uptake (P = 0.002), comparable to uptake in tumors with low HER2 expression. Conclusion: To our knowledge, the Sel-tagging technique is the first that enables site-specific C-11-radiolabeling of proteins. Here we present the finding that, in a favorable combination between radionuclide half-life and in vivo pharmacokinetics of the Affibody molecules, C-11-labeled Set-tagged Z(HER2:342) can successfully be used for rapid and repeated PET studies of HER2 expression in tumors.
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