| 1. |
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| 2. |
- McDonnell, J.J., et al.
(författare)
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How old is streamwater? : Open questions in catchment transit time conceptualization, modelling and analysis
- 2010
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Ingår i: Hydrological Processes. - : John Wiley & Sons. - 0885-6087 .- 1099-1085. ; 24:12, s. 1745-1754
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Tidskriftsartikel (refereegranskat)abstract
- The time water spends travelling subsurface through a catchment to the stream network (i.e. the catchment water transit time) fundamentally describes the storage, flow pathway heterogeneity and sources of water in a catchment. The distribution of transit times reflects how catchments retain and release water and solutes that in turn set biogeochemical conditions and affect contamination release or persistence. Thus, quan- tifying the transit time distribution provides an important constraint on biogeochemical processes and catchment sensitivity to anthropogenic inputs, contamination and land-use change. Although the assumptions and limitations of past and present transit time modelling approaches have been recently reviewed (McGuire and McDonnell, 2006), there remain many fundamental research challenges for understanding how transit time can be used to quantify catchment flow processes and aid in the development and testing of rainfall–runoff models. In this Commen- tary study, we summarize what we think are the open research questions in transit time research. These thoughts come from a 3-day workshop in January 2009 at the International Atomic Energy Agency in Vienna. We attempt to lay out a roadmap for this work for the hydrological commu- nity over the next 10 years. We do this by first defining what we mean (qualitatively and quantitatively) by transit time and then organize our vision around needs in transit time theory, needs in field studies of tran- sit time and needs in rainfall – runoff modelling. Our goal in presenting this material is to encourage widespread use of transit time information in process studies to provide new insights to catchment function and to inform the structural development and testing of hydrologic models.
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| 3. |
- Chen, Deliang, 1961, et al.
(författare)
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Summary of a workshop on extreme weather events in a warming world organized by the Royal Swedish Academy of Sciences
- 2020
-
Ingår i: Tellus Series B-Chemical and Physical Meteorology. - : Stockholm University Press. - 1600-0889 .- 0280-6509. ; 72:1
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is not only about changes in means of climatic variables such as temperature, precipitation and wind, but also their extreme values which are of critical importance to human society and ecosystems. To inspire the Swedish climate research community and to promote assessments of international research on past and future changes in extreme weather events against the global climate change background, the Earth Science Class of the Royal Swedish Academy of Sciences organized a workshop entitled 'Extreme weather events in a warming world' in 2019. This article summarizes and synthesizes the key points from the presentations and discussions of the workshop on changes in floods, droughts, heat waves, as well as on tropical cyclones and extratropical storms. In addition to reviewing past achievements in these research fields and identifying research gaps with a focus on Sweden, future challenges and opportunities for the Swedish climate research community are highlighted.
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| 4. |
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| 5. |
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| 6. |
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| 7. |
- Rodhe, A., Seibert, J., Seibert, P. & Eklund, A.
(författare)
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Groundwater Dynamics in a Till Hillslope: Flow Directions, Gradients and Delay
- 2001
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Ingår i: Poster presented at AGU Chapman Conference State-of-the-Art of Hillslope Hydrology, Sunriver, Oregon, October 8-12, 2001.
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Konferensbidrag (refereegranskat)
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| 8. |
- Schwartz, Stephen E., et al.
(författare)
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Why Hasn't Earth Warmed as Much as Expected?
- 2010
-
Ingår i: Journal of Climate. - 0894-8755 .- 1520-0442. ; 23:10, s. 2453-2464
-
Tidskriftsartikel (refereegranskat)abstract
- The observed increase in global mean surface temperature (GMST) over the industrial era is less than 40% of that expected from observed increases in long-lived greenhouse gases together with the best-estimate equilibrium climate sensitivity given by the 2007 Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). Possible reasons for this warming discrepancy are systematically examined here. The warming discrepancy is found to be due mainly to some combination of two factors: the IPCC best estimate of climate sensitivity being too high and/or the greenhouse gas forcing being partially offset by forcing by increased concentrations of atmospheric aerosols; the increase in global heat content due to thermal disequilibrium accounts for less than 25% of the discrepancy, and cooling by natural temperature variation can account for only about 15%. Current uncertainty in climate sensitivity is shown to preclude determining the amount of future fossil fuel CO2 emissions that would be compatible with any chosen maximum allowable increase in GMST; even the sign of such allowable future emissions is unconstrained. Resolving this situation, by empirical determination of the earth's climate sensitivity from the historical record over the industrial period or through use of climate models whose accuracy is evaluated by their performance over this period, is shown to require substantial reduction in the uncertainty of aerosol forcing over this period.
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| 9. |
- Shen, Xianli, et al.
(författare)
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Glioma-induced inhibition of caspase-3 in microglia promotes a tumor-supportive phenotype
- 2016
-
Ingår i: Nature Immunology. - : Springer Science and Business Media LLC. - 1529-2908 .- 1529-2916. ; 17:11, s. 1282-1290
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Tidskriftsartikel (refereegranskat)abstract
- Glioma cells recruit and exploit microglia (the resident immune cells of the brain) for their proliferation and invasion ability. The underlying molecular mechanism used by glioma cells to transform microglia into a tumor-supporting phenotype has remained elusive. We found that glioma-induced microglia conversion was coupled to a reduction in the basal activity of microglial caspase-3 and increased S-nitrosylation of mitochondria-associated caspase-3 through inhibition of thioredoxin-2 activity, and that inhibition of caspase-3 regulated microglial tumor-supporting function. Furthermore, we identified the activity of nitric oxide synthase 2 (NOS2, also known as iNOS) originating from the glioma cells as a driving stimulus in the control of microglial caspase-3 activity. Repression of glioma NOS2 expression in vivo led to a reduction in both microglia recruitment and tumor expansion, whereas depletion of microglial caspase-3 gene promoted tumor growth. Our results provide evidence that inhibition of the denitrosylation of S-nitrosylated procaspase-3 mediated by the redox protein Trx2 is a part of the microglial pro-tumoral activation pathway initiated by glioma cancer cells.
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| 10. |
- Beldring, S, et al.
(författare)
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Kinematic wave approximations to hillslope hydrological processes in tills
- 2000
-
Ingår i: HYDROLOGICAL PROCESSES. - : JOHN WILEY & SONS LTD. - 0885-6087. ; 14:4, s. 727-745
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Tidskriftsartikel (refereegranskat)abstract
- This work has been carried out within the framework of NOPEX - a NOrthern hemisphere climate Processes land surface EXperiment. Its purpose is to describe the spatial variability of groundwater levels and soil moisture content and their influence on runof
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| 11. |
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| 12. |
- Bender, Frida A-M, 1978-
(författare)
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Earth's albedo in a changing climate
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The albedo is a key parameter in the radiative budget of the Earth and a primary determinant of the planetary temperature and is therefore also central to questions regarding climate stability, climate change and climate sensitivity. Climate models and satellite observations are essential for studying the albedo, and the parameters determining it, on large spatial and temporal scales. Although climate models are able to capture the large-scale characteristics of the albedo, a bias is found between modelled and observed global albedo estimates, and on a regional scale particular problematic regions can be identified. Cloud parameters, that are of great importance for determining the albedo, vary widely among models, but lack of observations makes constraining models, and even evaluating models, difficult. The freedom of variability for cloud parameters can be used to make models agree with observations of the better constrained radiative budget. It is shown that tuning a model to different radiative budget estimates by altering cloud parameters can influence the climate sensitivity of the model, but the effect seen is small, compared to the range of climate sensitivities estimated by different models. Despite their different parameterizations of clouds, aerosols etc., models do have fundamental features in common, which can further the understanding of the real climate system. For instance it is found that sensitivity to volcanic forcing is related to climate sensitivity in an ensemble of models. If this relation is valid for the real climate as well, observations of the volcanic sensitivity can help restrict the climate sensitivity. The range of climate sensitivity estimates in models can largely be attributed to variations in cloud response to forcing. It is found that in models with high climate sensitivity changes in cloud cover and cloud reflectivity enhance a positive radiative forcing due to increased CO2 concentrations, feeding back on the warming and in models with low climate sensitivity, cloud response counteracts the positive radiative forcing and warming induced by the same forcing. As a consequence the total albedo response to increased CO2 forcing is found to be stronger (more negative) in high sensitivity models and vice versa. Cloud albedo and its variation between different cloud regimes, is important in this regard, yet not well known. A method based on the relation between cloud fraction and albedo is presented, giving a way to estimate regional cloud albedo, primarily for homogeneous cloud regimes, but possibly also extended to a global scale.
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| 13. |
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| 14. |
- Bockgård, N., Rodhe, A.
(författare)
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An experimental study of groundwater recharge to fractured bedrock
- 2003
-
Ingår i: Proceedings of the IAH International Conference on GROUNDWATER IN FRACTURED ROCKS, Prague 15-19 September 2003,J. Krasny, Z. Hrkal, J. Bruthans (Eds.). - : Prague: International Association of Hydrogeologists. - 929220002X
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Konferensbidrag (refereegranskat)
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| 15. |
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| 16. |
- Finnveden, G., et al.
(författare)
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Evaluation of integration of sustainable development in higher education in Sweden
- 2020
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Ingår i: International Journal of Sustainability in Higher Education. - : Emerald. - 1467-6370. ; 21:4, s. 685-698
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose Since 2006, higher education institutions (HEIs) in Sweden, should according to the Higher Education Act, promote sustainable development (SD). In 2016, the Swedish Government asked the Swedish higher education authority to evaluate how this study is proceeding. The authority chose to focus on education. This paper aims to produce a report on this evaluation. Design/methodology/approach All 47 HEIs in Sweden were asked to write a self-evaluation report based on certain evaluation criteria. A panel was appointed consisting of academics and representatives for students and working life. The panel wrote an evaluation of each HEI, a report on general findings and recommendations, and gave an overall judgement of each HEI in two classes as follows: the HEI has well-developed processes for integration of SD in education or the HEI needs to develop their processes. Findings Overall, a mixed picture developed. Most HEIs could give examples of programmes or courses where SD was integrated. However, less than half of the HEIs had overarching goals for integration of SD in education or had a systematic follow-up of these goals. Even fewer worked specifically with pedagogy and didactics, teaching and learning methods and environments, sustainability competences or other characters of education for SD. Overall, only 12 out of 47 got a higher judgement. Originality/value This is a unique study in which all HEIs in a country are evaluated. This provides unique possibilities for identifying success factors and barriers. The importance of the leadership of the HEIs became clear.
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| 17. |
- HARRIS, DM, et al.
(författare)
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HYDROGRAPH SEPARATION USING CONTINUOUS OPEN SYSTEM ISOTOPE MIXING
- 1995
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Ingår i: WATER RESOURCES RESEARCH. - : AMER GEOPHYSICAL UNION. - 0043-1397. ; 31:1, s. 157-171
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We propose a new hydrograph separation method for runoff source modeling based on continuous open system isotope mixing using a variable source area and three isotopic reservoirs. The three reservoirs are (1) direct precipitation on saturated areas, (2) a
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| 18. |
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| 19. |
- Jenkins, A., et al.
(författare)
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HYDROLOGY
- 1994
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Ingår i: BIOGEOCHEMISTRY OF SMALL CATCHMENTS. - 0471937231 ; , s. 31-54
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Konferensbidrag (refereegranskat)
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| 20. |
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| 21. |
- Lidgren, A, et al.
(författare)
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A systemic approach to incorporate sustainability into university courses and curricula
- 2006
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526. ; 14:9-11, s. 797-809
-
Tidskriftsartikel (refereegranskat)abstract
- This article is based on an analysis of Lund University that took place during the summer and autumn of 2004 (available for download at www.iiiee.lu.se, click library and publications). The university had experienced a loss of momentum in their progress regarding environmental issues. The purpose of the study was to identify barriers to including sustainability-related content throughout Lund University curricula, and eventually to develop solutions to eliminate/overcome these barriers. The article describes how Meadows' "Places to intervene in a system" [Meadows D. Leverage points: places to intervene in a system. Hartland, VT, USA: Sustainability Institute; 1999] was used as a tool to systematically discover these barriers. The same intervention places are used as a basis for deriving solutions to eliminate/overcome the barriers. The main conclusions of this article are that Meadows list can be a useful tool to a. systematically identify and characterise the barriers towards achieving the organisational objective of incorporating SD into courses and curricula; b. identify ways to overcome these barriers; c. increase chances that these barriers are addressed with sufficient leverage. The authors also experienced that the work method described here provides excellent fuel for creativity. (c) 2006 Elsevier Ltd. All rights reserved.
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| 22. |
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| 23. |
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| 24. |
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| 25. |
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| 26. |
- Petersen, S. O., et al.
(författare)
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In-vitro method and model to estimate methane emissions from liquid manure management on pig and dairy farms in four countries
- 2024
-
Ingår i: Journal of Environmental Management. - : Academic Press. - 0301-4797 .- 1095-8630. ; 353
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Tidskriftsartikel (refereegranskat)abstract
- Methane (CH4) emissions from manure management on livestock farms are a key source of greenhouse gas emissions in some regions and for some production systems, and the opportunities for mitigation may be significant if emissions can be adequately documented. We investigated a method for estimating CH4 emissions from liquid manure (slurry) that is based on anaerobic incubation of slurry collected from commercial farms. Methane production rates were used to derive a parameter of the Arrhenius temperature response function, lnA', representing the CH4 production potential of the slurry at the time of sampling. Results were used for parameterization of an empirical model to estimate annual emissions with daily time steps, where CH4 emissions from individual sources (barns, outside storage tanks) can be calculated separately. A monitoring program was conducted in four countries, i.e., Denmark, Sweden, Germany and the Netherlands, during a 12-month period where slurry was sampled to represent barn and outside storage on finishing pig and dairy farms. Across the four countries, lnA' was higher in pig slurry compared to cattle slurry (p < 0.01), and higher in slurry from barns compared to outside storage (p < 0.01). In a separate evaluation of the incubation method, in-vitro CH4 production rates were comparable with in-situ emissions. The results indicate that lnA' in barns increases with slurry age, probably due to growth or adaptation of the methanogenic microbial community. Using lnA' values determined experimentally, empirical models with daily time steps were constructed for finishing pig and dairy farms and used for scenario analyses. Annual emissions from pig slurry were predicted to be 2.5 times higher than those from cattle slurry. Changing the frequency of slurry export from the barn on the model pig farm from 40 to 7 d intervals reduced total annual CH4 emissions by 46 %; this effect would be much less on cattle farms with natural ventilation. In a scenario with cattle slurry, the empirical model was compared with the current IPCC methodology. The seasonal dynamics were less pronounced, and annual CH4 emissions were lower than with the current methodology, which calls for further investigations. Country-specific models for individual animal categories and point sources could be a tool for assessing CH4 emissions and mitigation potentials at farm level.
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| 27. |
- Rockström, Johan, et al.
(författare)
-
A safe operating space for humanity
- 2013
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Ingår i: The Future of Nature. - : Yale University Press. - 9780300184617 ; , s. 491-501
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Bokkapitel (refereegranskat)
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| 28. |
- Rockström, Johan, et al.
(författare)
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A safe operating space for humanity
- 2009
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 461:7263, s. 472-475
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Tidskriftsartikel (refereegranskat)
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| 29. |
- Rockström, Johan, et al.
(författare)
-
Planetary Boundaries : Exploring the Safe Operating Space for Humanity
- 2009
-
Ingår i: Ecology and Society. - 1708-3087. ; 14:2, s. 32-
-
Tidskriftsartikel (refereegranskat)abstract
- Anthropogenic pressures on the Earth System have reached a scale where abrupt global environmental change can no longer be excluded. We propose a new approach to global sustainability in which we define planetary boundaries within which we expect that humanity can operate safely. Transgressing one or more planetary boundaries may be deleterious or even catastrophic due to the risk of crossing thresholds that will trigger non-linear, abrupt environmental change within continental- to planetary-scale systems. We have identified nine planetary boundaries and, drawing upon current scientific understanding, we propose quantifications for seven of them. These seven are climate change (CO2 concentration in the atmosphere <350 ppm and/or a maximum change of +1 W m(-2) in radiative forcing); ocean acidification (mean surface seawater saturation state with respect to aragonite >= 80% of pre-industrial levels); stratospheric ozone (<5% reduction in O-3 concentration from pre-industrial level of 290 Dobson Units); biogeochemical nitrogen (N) cycle (limit industrial and agricultural fixation of N-2 to 35 Tg N yr(-1)) and phosphorus (P) cycle (annual P inflow to oceans not to exceed 10 times the natural background weathering of P); global freshwater use (<4000 km(3) yr(-1) of consumptive use of runoff resources); land system change (<15% of the ice-free land surface under cropland); and the rate at which biological diversity is lost (annual rate of <10 extinctions per million species). The two additional planetary boundaries for which we have not yet been able to determine a boundary level are chemical pollution and atmospheric aerosol loading. We estimate that humanity has already transgressed three planetary boundaries: for climate change, rate of biodiversity loss, and changes to the global nitrogen cycle. Planetary boundaries are interdependent, because transgressing one may both shift the position of other boundaries or cause them to be transgressed. The social impacts of transgressing boundaries will be a function of the social-ecological resilience of the affected societies. Our proposed boundaries are rough, first estimates only, surrounded by large uncertainties and knowledge gaps. Filling these gaps will require major advancements in Earth System and resilience science. The proposed concept of "planetary boundaries" lays the groundwork for shifting our approach to governance and management, away from the essentially sectoral analyses of limits to growth aimed at minimizing negative externalities, toward the estimation of the safe space for human development. Planetary boundaries define, as it were, the boundaries of the "planetary playing field" for humanity if we want to be sure of avoiding major human-induced environmental change on a global scale.
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| 30. |
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| 31. |
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| 32. |
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| 33. |
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| 34. |
- Rodhe, A, et al.
(författare)
-
Transit times for water in a small till catchment from a step shift in the oxygen 18 content of the water input
- 1996
-
Ingår i: Water resources research. - 0043-1397 .- 1944-7973. ; 32:12, s. 3497-3511
-
Tidskriftsartikel (refereegranskat)abstract
- A 6,300-m(2) catchment in SW Sweden was covered by a roof and irrigated by deacidified lake water. The delta(18)O of lake water differed from that of soil water and groundwater in the catchment, making it possible to follow the replacement of old (preirrigation) water by new (irrigation) water. After 7.5 months of irrigation the old water in the catchment had been replaced by new water. The breakthrough curve for new water gave a nearly exponential distribution of flow corrected transit times, with a mean transit time corresponding to a runoff of 54 mm. The estimated outflow of old water by runoff and evapotranspiration, 186 mm, compared well with independent estimates of the water storage at the onset of irrigation, 205 mm. The spatial pattern of the delta(18)O of soil water and groundwater within the catchment demonstrated the strong influence of the topography on the water flow.
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| 35. |
- Rodhe, A, et al.
(författare)
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Wetland occurrence in relation to topography: a test of topographic indices as moisture indicators
- 1999
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Ingår i: AGRICULTURAL AND FOREST METEOROLOGY. - : ELSEVIER SCIENCE BV. - 0168-1923. ; 98-9, s. 325-340
-
Tidskriftsartikel (refereegranskat)abstract
- Information about the spatial distributions of soil moisture or groundwater levels is needed for aggregation of soil-vegetation-atmosphere-transfer (SVAT) models. The possibility of predicting wetness distributions in catchments from topographic data was
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| 36. |
- Rodhe, Johanna, et al.
(författare)
-
Spatio-temporal activation of caspase-8 in myeloid cells upon ischemic stroke
- 2016
-
Ingår i: Acta Neuropathologica Communications. - : Springer Science and Business Media LLC. - 2051-5960. ; 4, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Ischemic stroke (caused by thrombosis, embolism or vasoconstriction) lead to the recruitment and activation of immune cells including resident microglia and infiltrating peripheral macrophages, which contribute to an inflammatory response involved in regulation of the neuronal damage. We showed earlier that upon pro-inflammatory stimuli, the orderly activation of caspase-8 and caspase-3/7 regulates microglia activation through a protein kinase C-δ dependent pathway. Here, we present in vivo evidence for the activation of caspase-8 and caspase-3 in microglia/macrophages in post-mortem tissue from human ischemic stroke subjects. Indeed, CD68-positive microglia/macrophages in the ischemic peri-infarct area exhibited significant expression of the cleaved and active form of caspase-8 and caspase-3. The temporal and spatial activation of caspase-8 was further investigated in a permanent middle cerebral artery occlusion mouse model of ischemic stroke. Increasing levels of active caspase-8 was found in Iba1-positive cells over time in the peri-infarct area, at 6, 24 and 48 h after artery occlusion. Analysis of post-mortem brain tissue from human subject who suffered two stroke events, referred as recent and old stroke, revealed that expression of cleaved caspase-8 and -3 in CD68-positive cells could only be found in the recent stroke area. Analysis of cleaved caspase-8 and -3 expressions in a panel of human stroke cases arranged upon days-after stroke and age-matched controls suggested that the expression of these caspases correlated with the time of onset of stroke. Collectively, these data illustrate the temporal and spatial activation of caspase-8 and -3 in microglia/macrophages occurring upon ischemic stroke and suggest that the expression of these caspases could be used in neuropathological diagnostic work.
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| 37. |
- Rodhe, Lena, et al.
(författare)
-
Ammonia emissions after application of human urine to a clay soil for barley growth
- 2004
-
Ingår i: Nutrient Cycling in Agroecosystems. - 1385-1314 .- 1573-0867. ; 68:2, s. 191-198
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Tidskriftsartikel (refereegranskat)abstract
- Important amounts of plant nutrients excreted by humans are found in human urine. This provides the motivation for separating urine and recycling it, as fertiliser, back to agricultural land for food or fodder production. There are some housing estates in Sweden, both blocks of flats and separate houses, in which urine-separating toilets have been installed. The urine is stored in covered basins and spread on agricultural land. The objective of the present study was to evaluate the influence of application rate, application techniques and time on NH3 emissions after application of source-separated human urine. Human urine was spread at different application rates (10, 20 and 60 Mg ha-1) before sowing (year 1 to 3) and when the barley crop was 20-30 cm high (year 2). Urine was spread with a plot spreader using two band-application techniques (with bands 0.25 m apart): trailing hoses and trailing shoes. In spring, band-spread urine with trailing hoses was incorporated with a harrow four hours after application. The four (year 1 and 3) or six (year 2) treatments were organised into a randomised block design with three replicates. An equilibrium concentration method was used for measuring ammonia emissions directly after application. After spring application with trailing hoses and harrowing after four hours, the nitrogen [N] loss as ammonia [NH3], average over 3 years, was 5% of the applied N, irrespective of the application rate. The largest loss (10% of the applied N) was measured after application of 60 t of urine per hectare in spring. Hardly any NH 3 loss occurred after incorporation with a harrow, with the exception of the highest application rate. Loss of NH3 was very low, close to 1% of the applied N, when the urine was incorporated directly into the soil in spring by band application with trailing shoes. Virtually no emissions were detected when the urine was applied to the growing crop, neither by trailing hoses nor by trailing shoes. This study shows that it is possible to apply human urine on bare soil or in growing barley crop with very low losses of N as NH3. Together with careful handling and the use of covered storage, nutrients in human urine could be recycled from households to agricultural land with low NH3 emissions.
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| 38. |
- Rodhe, Lena, et al.
(författare)
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Performance of slurry injectors compared with band spreading on three Swedish soils with ley
- 2005
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Ingår i: Biosystems Engineering. - : Elsevier BV. - 1537-5110 .- 1537-5129. ; 92:1, s. 107-118
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Tidskriftsartikel (refereegranskat)abstract
- The main objective of the present study was to evaluate different injection methods for slurry to ley on three different soils. A further objective was to study the effect of soil moisture on the working depth of an injector and on the slurry infiltration rate. In full-scale experiments, the placement of slurry, ammonia emissions and yield were measured after injection with three techniques: pressurised injection, shallow injection with V-shaped discs, and shallow injection with two angled discs. In an adjacent experiment the effect of soil moisture was studied. The performance varied between the injectors and only the injector with angled discs was able to place the slurry in ley below the soil surface on all soils studied. The ammonia release was on average halved after injection with angled discs compared with band spreading, giving a mean ammonia loss of 39% of the total ammoniacal nitrogen (TAN) applied. Despite the reduction in ammonia losses with the angled disc injector, this did not result in higher dry matter yield or higher nitrogen efficiency of the second cut compared with band spreading. The working depth of a slurry injector increased significantly with increasing soil water content. © 2005 Silsoe Research Institute. All rights reserved.
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| 39. |
- Seibert, J., Rodhe, A., Bishop, K.
(författare)
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A new conceptual model for hillslope runoff, groundwater and oxygen-18
- 2001
-
Ingår i: Freiburger Schriften zur Hydrologie, Band 13: Runoff Generation and Implications for River Basin Modelling, Proceedings of the International Workshop 9-13 October 2000, Institute of Hydrology, University of Freiburg i.Br./Germany. ; , s. 118-127
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Konferensbidrag (refereegranskat)
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| 40. |
- Soto Gómez, Agnes Jane, et al.
(författare)
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Remotely Sensed Nightlights to Map Societal Exposure to Hydrometeorological Hazards
- 2015
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Ingår i: Remote Sensing. - : MDPI AG. - 2072-4292. ; 7:9, s. 12380-12399
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Tidskriftsartikel (refereegranskat)abstract
- This study used remotely sensed maps of nightlights to investigate the etiology of increasing disaster losses from hydrometeorological hazards in a data-scarce area. We explored trends in the probability of occurrence of hazardous events (extreme rainfall) and exposure of the local population as components of risk. The temporal variation of the spatial distribution of exposure to hydrometeorological hazards was studied using nightlight satellite imagery as a proxy. Temporal (yearly) and spatial (1 km) resolution make them more useful than official census data. Additionally, satellite nightlights can track informal (unofficial) human settlements. The study focused on the Samala River catchment in Guatemala. The analyses of disasters, using DesInventar Disaster Information Management System data, showed that fatalities caused by hydrometeorological events have increased. Such an increase in disaster losses can be explained by trends in both: (i) catchment conditions that tend to lead to more frequent hydrometeorological extremes (more frequent occurrence of days with wet conditions); and (ii) increasing human exposure to hazardous events (as observed by amount and intensity of nightlights in areas close to rivers). Our study shows the value of remote sensing data and provides a framework to explore the dynamics of disaster risk when ground data are spatially and temporally limited.
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| 41. |
- Sundvall, Pär-Daniel, et al.
(författare)
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Interleukin-6 concentrations in the urine and dipstick analyses were related to bacteriuria but not symptoms in the elderly: a cross sectional study of 421 nursing home residents
- 2014
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Ingår i: BMC Geriatrics. - : Springer Science and Business Media LLC. - 1471-2318. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: Up to half the residents of nursing homes for the elderly have asymptomatic bacteriuria (ABU), which should not be treated with antibiotics. A complementary test to discriminate between symptomatic urinary tract infections (UTI) and ABU is needed, as diagnostic uncertainty is likely to generate significant antibiotic overtreatment. Previous studies indicate that Interleukin-6 (IL-6) in the urine might be suitable as such a test. The aim of this study was to investigate the association between laboratory findings of bacteriuria, IL-6 in the urine, dipstick urinalysis and newly onset symptoms among residents of nursing homes. Methods: In this cross sectional study, voided urine specimens for culture, urine dipstick and IL-6 analyses were collected from all residents capable of providing a voided urine sample, regardless of the presence of symptoms. Urine specimens and symptom forms were provided from 421 residents of 22 nursing homes. The following new or increased nonspecific symptoms occurring during the previous month were registered; fatigue, restlessness, confusion, aggressiveness, loss of appetite, frequent falls and not being herself/himself, as well as symptoms from the urinary tract; dysuria, urinary urgency and frequency. Results: Recent onset of nonspecific symptoms was common among elderly residents of nursing homes (85/421). Urine cultures were positive in 32% (135/421), Escherichia coli was by far the most common bacterial finding. Residents without nonspecific symptoms had positive urine cultures as often as those with nonspecific symptoms with a duration of up to one month. Residents with positive urine cultures had higher concentrations of IL-6 in the urine (p < 0.001). However, among residents with positive urine cultures there were no differences in IL-6 concentrations or dipstick findings between those with or without nonspecific symptoms. Conclusions: Nonspecific symptoms among elderly residents of nursing homes are unlikely to be caused by bacteria in the urine. This study could not establish any clinical value of using dipstick urinalysis or IL-6 in the urine to verify if bacteriuria was linked to nonspecific symptoms.
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- van der Velde, Ype, et al.
(författare)
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Consequences of mixing assumptions for time-variable travel time distributions
- 2015
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Ingår i: Hydrological Processes. - : Wiley. - 0885-6087 .- 1099-1085. ; 29:16, s. 3460-3474
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Tidskriftsartikel (refereegranskat)abstract
- The current generation of catchment travel time distribution (TTD) research, integrating nearly three decades of work since publication of Water's Journey from Rain to Stream, seeks to represent the full distribution in catchment travel times and its temporal variability. Here, we compare conceptualizations of increasing complexity with regards to mixing of water storages and evaluate how these assumptions influence time-variable TTD estimates for two catchments with contrasting climates: the Gardsjon catchment in Sweden and the Marshall Gulch catchment in Arizona, USA. Our results highlight that, as long as catchment TTDs cannot be measured directly but need to be inferred from input-output signals of catchments, the inferred catchment TTDs depend strongly on the underlying assumptions of mixing within a catchment. Furthermore, we found that the conceptualization of the evapotranspiration flux strongly influences the inferred travel times of stream discharge. For the wet and forested Gardsjon catchment in Sweden, we inferred that evapotranspiration most likely resembles a completely mixed sample of the water stored in the catchment; however, for the drier Marshall Gulch catchment in Arizona, evapotranspiration predominantly contained the younger water stored in the catchment. For the Marshall Gulch catchment, this higher probability for young water in evapotranspiration resulted in older water in the stream compared to travel times inferred with assumptions of complete mixing. New observations that focus on the TTD of the evapotranspiration flux and the actual travel time of water through a catchment are necessary to improve identification of mixing and consequently travel times of stream water. Copyright (c) 2014 John Wiley & Sons, Ltd.
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