| 1. |
- Downing, Andrea S., et al.
(författare)
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Coupled human and natural system dynamics as key to the sustainability of Lake Victoria's ecosystem services
- 2014
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Ingår i: Ecology and Society. - 1708-3087. ; 19:4, s. 31-
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Tidskriftsartikel (refereegranskat)abstract
- East Africa's Lake Victoria provides resources and services to millions of people on the lake's shores and abroad. In particular, the lake's fisheries are an important source of protein, employment, and international economic connections for the whole region. Nonetheless, stock dynamics are poorly understood and currently unpredictable. Furthermore, fishery dynamics are intricately connected to other supporting services of the lake as well as to lakeshore societies and economies. Much research has been carried out piecemeal on different aspects of Lake Victoria's system; e.g., societies, biodiversity, fisheries, and eutrophication. However, to disentangle drivers and dynamics of change in this complex system, we need to put these pieces together and analyze the system as a whole. We did so by first building a qualitative model of the lake's social-ecological system. We then investigated the model system through a qualitative loop analysis, and finally examined effects of changes on the system state and structure. The model and its contextual analysis allowed us to investigate system-wide chain reactions resulting from disturbances. Importantly, we built a tool that can be used to analyze the cascading effects of management options and establish the requirements for their success. We found that high connectedness of the system at the exploitation level, through fisheries having multiple target stocks, can increase the stocks' vulnerability to exploitation but reduce society's vulnerability to variability in individual stocks. We describe how there are multiple pathways to any change in the system, which makes it difficult to identify the root cause of changes but also broadens the management toolkit. Also, we illustrate how nutrient enrichment is not a self-regulating process, and that explicit management is necessary to halt or reverse eutrophication. This model is simple and usable to assess system-wide effects of management policies, and can serve as a paving stone for future quantitative analyses of system dynamics at local scales.
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| 2. |
- Alling, Vanja, et al.
(författare)
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The role of biochar in retaining nutrients in amended tropical soils
- 2014
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Ingår i: Journal of Plant Nutrition And Soil Science/Zeitschrift für Pflanzenernahrung und Bodenkunde. - : Wiley. - 1436-8730 .- 1522-2624. ; 177:5, s. 671-680
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the effect of biochar amendments on the retention and availability of plant nutrients and Al in seven acidic tropical soils from Zambia and Indonesia. The experiments carried out investigated whether the adsorption capacity of NH4+ in the soils increased upon the addition of biochar and which effect biochar had on available concentrations of NO3-, K+, Mn2+, Mg2+, PO43-, and Al3+. These nutrients were selected as they represent those important to plant growth and soil quality. No significant increases or decreases in aqueous NH4+-N concentration with additions of biochar were detected. The Gaines-Thomas model was used in order to calculate selectivity coefficients for NH4+ exchange (K-gt values). Following the addition of biochar to soil, K-gt values decreased showing a reduction in the selective binding of NH4+ in the biochar amended soil compared to the control. The concentration of NO3- increased following the addition of biochar to the soils. The addition of 5 and 10% biochar to the Indonesian soil did not significantly alter (t-test confidence level 0.05) the sorption of PO43- to the soil-biochar mixtures as compared to the soil alone. However, the addition of biochar to the soil from Zambia increased the sorption of PO43- compared to the soil alone. The concentrations of K+ and Mg2+ were significantly increased for almost all soils (t-test at the 0.05 confidence level) following the addition of biochar. Addition of biochar to all but two soils significantly decreased (t-test confidence level 0.05) Mn2+ concentrations. The concentration of Al3+ in the soils decreased exponentially significantly (t-test confidence level 0.05) following the amendment of biochar in accordance with the increase in pH observed when biochar was added to the soil. These results show that biochar has the ability to release essential plant growth nutrients as well as alleviate Al toxicity in these soils.
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| 3. |
- Cornelissen, Jan J., et al.
(författare)
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The European LeukemiaNet AML Working Party consensus statement on allogeneic HSCT for patients with AML in remission: an integrated-risk adapted approach
- 2012
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Ingår i: Nature Reviews Clinical Oncology. - : Springer Science and Business Media LLC. - 1759-4782 .- 1759-4774. ; 9:10, s. 579-590
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Forskningsöversikt (refereegranskat)abstract
- Allogeneic haematopoietic stem-cell transplantation (HSCT) is frequently applied as part of the treatment in patients with acute myeloid leukaemia (AML) in their first or subsequent remission. Allogeneic HSCT reduces relapse, but nonrelapse mortality and morbidity might counterbalance this beneficial effect. Here, we review recent studies reporting new disease-specific prognostic markers, in addition to allogeneic-HSCT-related risk factors, which can be assessed at specific time points during treatment. We propose risk assessment as a dynamic process during treatment, incorporating both disease-related and transplant-related factors for the decision to proceed either to allogeneic HSCT or to apply a nontransplant strategy. We suggest that allogeneic HSCT might be favoured if the projected disease-free survival is expected to improve by at least 10% based on an individual's risk assessment. The approach requires initial disease risk assessment, identifying a sibling or unrelated donor soon after diagnosis and the incorporation of time-dependent risk factors, all within the context of an integrated therapeutic management approach.
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| 4. |
- Martinsen, Vegard, et al.
(författare)
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Farmer-led maize biochar trials : Effect on crop yield and soil nutrients under conservation farming
- 2014
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Ingår i: Journal of Plant Nutrition And Soil Science/Zeitschrift für Pflanzenernahrung und Bodenkunde. - : Wiley. - 1436-8730 .- 1522-2624. ; 177:5, s. 681-695
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Tidskriftsartikel (refereegranskat)abstract
- In extensive farmer-led trials practicing conservation farming (CF) in three regions of Zambia (Mongu: sandy soils; Kaoma: sandy or loamy sand soils; Mkushi: sandy loam or loamy soils), we studied the effects of biochar made of maize cobs (0, 2, and 6 t ha(-1) corresponding to 0, 0.8, and 2.5% per basin) at different fertilizer rates of NPK and urea on crop yield of maize (Zea mays) and groundnuts (Arachis hypogaea). Conservation farming in this case combines minimum tillage (how basins), crop rotation and residue retention. For the first time, the effect of biochar on in situ soil nutrient supply rates [determined by buried Plant Root Simulator (PRS (TM)) exchange resins] was studied, as well as the effects of biochar on elemental composition of maize. Effects of 0-10% (w:w) biochar addition on soil physical and soil chemical properties were determined in the laboratory. At all sites there was a consistent positive response in crop yield upon the addition of biochar. However, due to a great variability between farms there were no significant differences in absolute yields between the treatments. In the sandy soils at Mongu, relative yields (i.e., percentage yield with biochar relative to the same fertilizer rate without biochar) of maize grains and maize stover were significantly increased at recommended fertilizer rates (232 +/- 60%) and at half the recommended rate (128 +/- 6%), respectively. In addition, biochar significantly increased concentrations of K and P in maize stover. In situ soil nutrient supply rates as measured by PRS (TM)-probes were highly spatially variable with no consistent effects of the different treatments in the three regions. By contrast, the fraction of plant available water (Vol.-%) significantly increased upon the addition of biochar in all three soils. The increase caused by 10% biochar addition was of factor 2.5 in Mongu (from 4.5% to 11.2%) and 1.2 in both Kaoma (from 14.7% to 18.2%) and Mkushi (from 18.2% to 22.7%). Cation exchange capacity, pH, and exchangeable K significantly increased upon the addition of 10% (w: w) biochar in all three regions with a subsequent increase in base saturation and decrease of available Al3+. Our findings suggest that the addition of biochar in combination with CF might have a positive impact on crop growth and that this positive effect is mainly caused by increases in plant-available water and decreased available Al.
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| 5. |
- Nagler, Arnon, et al.
(författare)
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Mobilized peripheral blood stem cells compared with bone marrow from HLA-identical siblings for reduced-intensity conditioning transplantation in acute myeloid leukemia in complete remission: a retrospective analysis from the Acute Leukemia Working Party of EBMT
- 2012
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Ingår i: European Journal of Haematology. - : John Wiley and Sons. - 0902-4441 .- 1600-0609. ; 89:3, s. 206-213
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Tidskriftsartikel (refereegranskat)abstract
- Reduced-intensity conditioning (RIC)-alloSCT is increasingly used for acute myelogenous leukemia. Limited data are available for the comparison of peripheral blood stem cells with bone marrow for RIC-alloSCT. We used the European Group for Blood and Marrow Transplantation (EBMT) ALWP data to compare the outcome of mobilized peripheral blood stem cells (PBSC) (n = 1430) vs. bone marrow (BM) (n = 107) for acute myelogenous leukemia (AML) patients with complete remission that underwent RIC-alloSCT from compatible sibling donors. The leukemia features, the disease status, and the time from diagnosis were similar between the two groups. Engraftment was achieved in 99% and 93% in the PBSC and BM groups, respectively (P andlt; 0.0001). The day of engraftment was significantly earlier for the PBSC vs. the BM group, 15 (159) and 19 (569), respectively (P andlt; 0.001). Acute GVHD, severe GVHD (grade IIIIV) and chronic GVHD did not differ between the groups. leukemia-free survival (LFS), relapse, and non-relapsed mortality (NRM) were 51 +/- 2%, 32 +/- 1%, and 17 +/- 1% vs. 50 +/- 6%, 38 +/- 6%, and 12 +/- 3% for the PBSC and BM groups, respectively. Our results indicate faster engraftment, but no difference in GVHD, LFS, relapse, and NRM when comparing PBSC to BM grafts from sibling donors following RIC conditioning. This is the first study comparing PBSC to BM grafts in the RIC setting, analyzing a homogeneous population of patients with AML in remission. Whether PBSC should be preferred for advanced phases of the disease, where the outcome is dominated by relapse incidences, needs further investigation.
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| 6. |
- Okkenhaug, Gudny, et al.
(författare)
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Antimony (Sb) Contaminated Shooting Range Soil : Sb Mobility and Immobilization by Soil Amendments
- 2013
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 47:12, s. 6431-6439
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Tidskriftsartikel (refereegranskat)abstract
- Antimony (Sb) in lead bullets poses a major environmental risk in shooting range soils. Here we studied the effect of iron (Fe)-based amendments on the mobility of Sb in contaminated soil from shooting ranges in Norway. Untreated soil showed high Sb concentrations in water extracts from batch tests (0.22-1.59 mg L-1) and soil leachate from column tests (0.3-0.7 mg L-1), occurring exclusively as Sb(V). Sorption of Sb to different iron-based sorbents was well described by the Freundlich equation (Fe-2(SO4)(3), log K-F = 6.35, n = 1.51; CFH-12 (Fe oxyhydroxide), log K-F = 4.16-4.32, n = 0.75-0.76); Fe-0 grit, log K-F = 3.26, n = 0.47). These sorbents mixed with soil (0.5 and 2% w/w), showed significant sorption of Sb in batch tests (46-92%). However, for Fe-2(SO4)(3) and CFH-12 liming was also necessary to prevent mobilization of lead, copper, and zinc. Column tests showed significant significant retention of Sb (89-98%) in soil amended with CFH-12 (2%) mixed with limestone (1%) compared to unamended soil. The sorption capacity of soils amended with Fe-0 (2%) increased steadily up to 72% over the duration period of the column test (64 days), most likely due to the gradual oxidation of Fe-0 to Fe oxyhydroxides. Based on the experimental results, CFH-12 and oxidized Fe-0 are effective amendments for the stabilization of Sb in shooting range soils.
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