| 1. |
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| 2. |
- Olsson, Lennart, et al.
(författare)
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GIS och studiet av globala miljöproblem
- 2002
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Ingår i: Geografiska Informationssystem - tillämpningsexempel. - 915405903 8 ; , s. 131-162
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Bokkapitel (populärvet., debatt m.m.)
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| 3. |
- Axelsson, Robert, et al.
(författare)
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Evaluation of Multi-level Social Learning for Sustainable Landscapes : Perspective of a Development Initiative in Bergslagen, Sweden
- 2013
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Ingår i: Ambio. - : Springer Netherlands. - 0044-7447 .- 1654-7209. ; 42:2, s. 241-253
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Tidskriftsartikel (refereegranskat)abstract
- To implement policies about sustainable landscapes and rural development necessitates social learning about states and trends of sustainability indicators, norms that define sustainability, and adaptive multi-level governance. We evaluate the extent to which social learning at multiple governance levels for sustainable landscapes occur in 18 local development initiatives in the network of Sustainable Bergslagen in Sweden. We mapped activities over time, and interviewed key actors in the network about social learning. While activities resulted in exchange of experiences and some local solutions, a major challenge was to secure systematic social learning and make new knowledge explicit at multiple levels. None of the development initiatives used a systematic approach to secure social learning, and sustainability assessments were not made systematically. We discuss how social learning can be improved, and how a learning network of development initiatives could be realized.
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| 4. |
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| 5. |
- Christiansen, Evald H, et al.
(författare)
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Instantaneous Wave-free Ratio versus Fractional Flow Reserve to Guide PCI.
- 2017
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Ingår i: The New England journal of medicine. - : Massachussetts Medical Society. - 1533-4406 .- 0028-4793. ; 376:19, s. 1813-1823
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Tidskriftsartikel (refereegranskat)abstract
- The instantaneous wave-free ratio (iFR) is an index used to assess the severity of coronary-artery stenosis. The index has been tested against fractional flow reserve (FFR) in small trials, and the two measures have been found to have similar diagnostic accuracy. However, studies of clinical outcomes associated with the use of iFR are lacking. We aimed to evaluate whether iFR is noninferior to FFR with respect to the rate of subsequent major adverse cardiac events.We conducted a multicenter, randomized, controlled, open-label clinical trial using the Swedish Coronary Angiography and Angioplasty Registry for enrollment. A total of 2037 participants with stable angina or an acute coronary syndrome who had an indication for physiologically guided assessment of coronary-artery stenosis were randomly assigned to undergo revascularization guided by either iFR or FFR. The primary end point was the rate of a composite of death from any cause, nonfatal myocardial infarction, or unplanned revascularization within 12 months after the procedure.A primary end-point event occurred in 68 of 1012 patients (6.7%) in the iFR group and in 61 of 1007 (6.1%) in the FFR group (difference in event rates, 0.7 percentage points; 95% confidence interval [CI], -1.5 to 2.8; P=0.007 for noninferiority; hazard ratio, 1.12; 95% CI, 0.79 to 1.58; P=0.53); the upper limit of the 95% confidence interval for the difference in event rates fell within the prespecified noninferiority margin of 3.2 percentage points. The results were similar among major subgroups. The rates of myocardial infarction, target-lesion revascularization, restenosis, and stent thrombosis did not differ significantly between the two groups. A significantly higher proportion of patients in the FFR group than in the iFR group reported chest discomfort during the procedure.Among patients with stable angina or an acute coronary syndrome, an iFR-guided revascularization strategy was noninferior to an FFR-guided revascularization strategy with respect to the rate of major adverse cardiac events at 12 months. (Funded by Philips Volcano; iFR SWEDEHEART ClinicalTrials.gov number, NCT02166736 .).
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| 6. |
- Escaned, Javier, et al.
(författare)
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Safety of the Deferral of Coronary Revascularization on the Basis of Instantaneous Wave-Free Ratio and Fractional Flow Reserve Measurements in Stable Coronary Artery Disease and Acute Coronary Syndromes
- 2018
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Ingår i: JACC. - : Elsevier. - 1936-8798 .- 1876-7605. ; 11:15, s. 1437-1449
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES The aim of this study was to investigate the clinical outcomes of patients deferred from coronary revascularization on the basis of instantaneous wave-free ratio (iFR) or fractional flow reserve (FFR) measurements in stable angina pectoris (SAP) and acute coronary syndromes (ACS). BACKGROUND Assessment of coronary stenosis severity with pressure guidewires is recommended to determine the need for myocardial revascularization. METHODS The safety of deferral of coronary revascularization in the pooled per-protocol population (n = 4,486) of the DEFINE-FLAIR (Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularisation) and iFR-SWEDEHEART (Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve in Patients With Stable Angina Pectoris or Acute Coronary Syndrome) randomized clinical trials was investigated. Patients were stratified according to revascularization decision making on the basis of iFR or FFR and to clinical presentation (SAP or ACS). The primary endpoint was major adverse cardiac events (MACE), defined as the composite of all-cause death, nonfatal myocardial infarction, or unplanned revascularization at 1 year. RESULTS Coronary revascularization was deferred in 2,130 patients. Deferral was performed in 1,117 patients (50%) in the iFR group and 1,013 patients (45%) in the FFR group (p < 0.01). At 1 year, the MACE rate in the deferred population was similar between the iFR and FFR groups (4.12% vs. 4.05%; fully adjusted hazard ratio: 1.13; 95% confidence interval: 0.72 to 1.79; p = 0.60). A clinical presentation with ACS was associated with a higher MACE rate compared with SAP in deferred patients (5.91% vs. 3.64% in ACS and SAP, respectively; fully adjusted hazard ratio: 0.61 in favor of SAP; 95% confidence interval: 0.38 to 0.99; p = 0.04). CONCLUSIONS Overall, deferral of revascularization is equally safe with both iFR and FFR, with a low MACE rate of about 4%. Lesions were more frequently deferred when iFR was used to assess physiological significance. In deferred patients presenting with ACS, the event rate was significantly increased compared with SAP at 1 year. (C) 2018 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation.
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| 7. |
- Götberg, Matthias, et al.
(författare)
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5-Year Outcomes of PCI Guided by Measurement of Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve
- 2022
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Ingår i: Journal of the American College of Cardiology. - : Elsevier. - 0735-1097 .- 1558-3597. ; 79:10, s. 965-974
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Instantaneous wave-free ratio (iFR) is a coronary physiology index used to assess the severity of coronary artery stenosis to guide revascularization. iFR has previously demonstrated noninferior short-term outcome compared to fractional flow reserve (FFR), but data on longer-term outcome have been lacking.OBJECTIVES: The purpose of this study was to investigate the prespecified 5-year follow-up of the primary composite outcome of all-cause mortality, myocardial infarction, and unplanned revascularization of the iFR-SWEDEHEART trial comparing iFR vs FFR in patients with chronic and acute coronary syndromes.METHODS: iFR-SWEDEHEART was a multicenter, controlled, open-label, registry-based randomized clinical trial using the Swedish Coronary Angiography and Angioplasty Registry for enrollment. A total of 2,037 patients were randomized to undergo revascularization guided by iFR or FFR.RESULTS: No patients were lost to follow-up. At 5 years, the rate of the primary composite endpoint was 21.5% in the iFR group and 19.9% in the FFR group (HR: 1.09; 95% CI: 0.90-1.33). The rates of all-cause death (9.4% vs 7.9%; HR: 1.20; 95% CI: 0.89-1.62), nonfatal myocardial infarction (5.7% vs 5.8%; HR: 1.00; 95% CI: 0.70-1.44), and unplanned revascularization (11.6% vs 11.3%; HR: 1.02; 95% CI: 0.79-1.32) were also not different between the 2 groups. The outcomes were consistent across prespecified subgroups.CONCLUSIONS: In patients with chronic or acute coronary syndromes, an iFR-guided revascularization strategy was associated with no difference in the 5-year composite outcome of death, myocardial infarction, and unplanned revascularization compared with an FFR-guided revascularization strategy. (Evaluation of iFR vs FFR in Stable Angina or Acute Coronary Syndrome [iFR SWEDEHEART]; NCT02166736)
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| 8. |
- Holm, Magnus, et al.
(författare)
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Non-Invasive Assessment of the Atrial Cycle Length during Atrial Fibrillation in Man: Introducing, Validating and Illustrating a New ECG Method
- 1998
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Ingår i: Cardiovascular Research. - 1755-3245. ; 38:1, s. 69-81
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Atrial fibrillation (AF) in man has previously been shown to include a wide variety of atrial activity. Assessment of the characteristics of this arrhythmia with a commonly applicable tool may therefore be important in the choice and evaluation of different therapeutic strategies. As the AF cycle length has been shown to correlate locally with atrial refractoriness and globally with the degree of atrial organization, with, in general, shorter cycle length during apparently random AF compared to more organized AF, we have developed a new method for non-invasive assessment of the AF cycle length using the surface and the esophagus (ESO) ECG. METHODS AND RESULTS: From the frequency spectrum of the residual ECG, created by suppression of the QRST complexes, the dominant atrial cycle length (DACL) was derived. By comparison with multiple intracardiac simultaneously acquired right and left AF cycle lengths in patients with paroxysmal AF, we found that the DACL in lead V1, ranging from 130 to 185 ms, well represented a spatial average of the right AF cycle lengths, whereas the DACL in the ESO ECG, ranging from 140 to 185 ms, reflected both the right and the left AF cycle length, where the influence from each structure depended on the atrial anatomy of the individual, as determined by MRI. In patients with chronic AF, the method was capable of following changes in the AF cycle length due to administration of D,L-sotalol and 5 min of ECG recording was sufficient for the DACL to be reproducible. CONCLUSIONS: We conclude that this new non-invasive method, named 'Frequency Analysis of Fibrillatory ECG' (FAF-ECG), is capable of assessing both the magnitude and the dynamics of the atrial fibrillation cycle length in man.
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| 9. |
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| 10. |
- Moberg, Christina, et al.
(författare)
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De unga gör helt rätt när de stämmer staten
- 2022
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Ingår i: Aftonbladet. - 1103-9000.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
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| 11. |
- Nygren, Martin, et al.
(författare)
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Identification of 2,3,7,8-substituted polychlorinated dioxins and dibenzofurans in environmental and human samples
- 1986. - 1
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Ingår i: Chlorinated dioxins and dibenzofurans in perspective. - Boca Raton : CRC Press. - 9781315891545 - 9781351070645 ; , s. 17-34
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are two series of tricyclic, almost planar aromatic compounds that exhibit very similar physical, chemical, and biological properties. The human exposure to PCDDs and PCDFs by milk consumption is not negligible. Detection levels in ecological and human samples should be orders of magnitude below the usual detection levels obtained in pesticide analyses. One objective of the study is to identify background levels of PCDDs and PCDFs in these samples, especially those of human origin. The spectrum of toxic effects is species dependent but for humans they include chloracne and porphyria cutane tarda and for other animals edema, thymic atrophy, teratogenicity, liver lesions and a slow wasting syndrome followed by death. It is evident that it is of particular importance to identify the ultimate source or sources of the toxic 2,3,7,8-substituted PCDDs and PCDFs found as background constituents in the environmental and human samples, especially the samples of mother's milk, which are of toxicological interest.
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| 12. |
- van Ittersum, Martin, et al.
(författare)
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Integrated Assessment of Agricultural and Environmental Policies – A Modular Framework for the EU (SEAMLESS)
- 2008
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Ingår i: Agricultural Systems. - : Elsevier BV. - 0308-521X. ; 96:1-3, s. 150-165
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedAgricultural systems continuously evolve and are forced to change as a result of a range of global and local driving forces. Agricultural technologies and agricultural, environmental and rural development policies are increasingly designed to contribute to the sustainability of agricultural systems and to enhance contributions of agricultural systems to sustainable development at large. The effectiveness and efficiency of such policies and technological developments in realizing desired contributions could be greatly enhanced if the quality of their ex-ante assessments were improved. Four key challenges and requirements to make research tools more useful for integrated assessment in the European Union were defined in interactions between scientists and the European Commission (EC), i.e., overcoming the gap between micro-macro level analysis, the bias in integrated assessments towards either economic or environmental issues, the poor re-use of models and hindrances in technical linkage of models. Tools for integrated assessment must have multi-scale capabilities and preferably be generic and flexible such that they can deal with a broad variety of policy questions. At the same time, to be useful for scientists, the framework must facilitate state-of-the-art science both on aspects of the agricultural systems and on integration. This paper presents the rationale, design and illustration of a component-based framework for agricultural systems (SEAMLESS Integrated Framework) to assess, ex-ante, agricultural and agri-environmental policies and technologies across a range of scales, from field-farm to region and European Union, as well as some global interactions. We have opted for a framework to link individual model and data components and a software infrastructure that allows a flexible (re-)use and linkage of components. The paper outlines the software infrastructure, indicators and model and data components. The illustrative example assesses effects of a trade liberalisation proposal on EU's agriculture and indicates how SEAMLESS addresses the four identified challenges for integrated assessment tools, i.e., linking micro and macro analysis, assessing economic, environmental, social and institutional indicators, (re-)using standalone model components for field, farm and market analysis and their conceptual and technical linkage.
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| 13. |
- Ahlberg, Erik, et al.
(författare)
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"Vi klimatforskare stödjer Greta och skolungdomarna"
- 2019
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Ingår i: Dagens nyheter (DN debatt). - 1101-2447.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- DN DEBATT 15/3. Sedan industrialiseringens början har vi använt omkring fyra femtedelar av den mängd fossilt kol som får förbrännas för att vi ska klara Parisavtalet. Vi har bara en femtedel kvar och det är bråttom att kraftigt reducera utsläppen. Det har Greta Thunberg och de strejkande ungdomarna förstått. Därför stödjer vi deras krav, skriver 270 klimatforskare.
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| 14. |
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| 15. |
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| 16. |
- Ahrens, Wolfgang, et al.
(författare)
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Occupational exposure to endocrine-disrupting compounds and biliary tract cancer among men
- 2007
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Ingår i: Scandinavian Journal of Work, Environment and Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 33:5, s. 387-396
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Tidskriftsartikel (refereegranskat)abstract
- Objectives This study investigated the association between cancer of the extrahepatic biliary tract and exposure to endocrine-disrupting compounds. Methods Altogether 183 men with histologically confirmed carcinoma of the extrahepatic biliary tract and 1938 matched controls were interviewed between 1995 and 1997 in the frame of an international multicenter case-control study in six European countries (Denmark, France, Germany, Italy, Spain, and Sweden). Selfreported job descriptions were converted to semiquantitative variables (intensity, probability, and duration of exposure) for 14 endocrine-disrupting compounds. The cases were compared with 1421 population controls and 517 colon adenocarcinoma patients. Odds ratios (OR) and 95% confidence intervals (95% CI) were obtained with unconditional logistic regression and adjusted for age, country, and gallstones. Results Occupational exposure to endocrine-disrupting compounds resulted in an OR of 1.4 (95% CI 1.0-2. 1) with no dose-effect relationship for cumulative exposure (low: OR 1.3, 95% CI 0.6-3.0; medium: OR 1.5, 95% CI0.8-2.7; high: OR 1.4, 95% CI 0.9-2.4) (only index participants). The elevated risk was restricted to extrahepatic bile ducts and ampulla Vateri (OR 1.7, 95% CI 1.0-2.6). The adjusted OR for cancer of the extrahepatic biliary tract after exposure to polychlorinated biphenyls was 2.8 (95% CI 1.3-5.9, only index participants). Conclusions The data show some associations between exposure to endocrine-disrupting compounds in the workplace and the risk for cancer of the extrahepatic biliary tract among men, particularly for the extrahepatic bile duct and ampulla of Vater. Polychlorinated biphenyls could possibly be a strong risk factor.
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| 17. |
- Ahrens, Wolfgang, et al.
(författare)
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Risk factors for extrahepatic biliary tract carcinoma in men: medical conditions and lifestyle: results from a European multicentre case-control study
- 2007
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Ingår i: European Journal of Gastroenterology and Hepathology. - 1473-5687. ; 19:8, s. 623-630
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To identify risk factors of carcinoma of the extrahepatic biliary tract in men. METHODS: Newly diagnosed and histologically confirmed patients, 35-70 years old, were interviewed between 1995 and 1997 in Denmark, Sweden, France, Germany and Italy. Population controls were frequency-matched by age and region. Adjusted odds ratios and 95%-confidence intervals were estimated by logistic regression. RESULTS: The analysis included 153 patients and 1421 controls. The participation proportion was 71% for patients and 61% for controls. Gallstone disease was corroborated as a risk factor for extrahepatic biliary tract carcinoma in men (odds ratio 2.49; 95% confidence interval 1.32-4.70), particularly for gall bladder tumors (odds ratio 4.68; 95% confidence interval 1.85-11.84). For a body mass index [height (m) divided by squared weight (kg2)] >30 at age 35 years, an excess risk was observed (odds ratio 2.58; 95% confidence interval 1.07-6.23, reference: body mass index 18.5-25) that was even stronger if the body mass index was >30 for the lowest weight in adulthood (odds ratio 4.68; 95% confidence interval 1.13-19.40). Infection of the gall bladder, chronic inflammatory bowel disease, hepatitis or smoking showed no clear association, whereas some increase in risk was suggested for consumption of 40-80 g alcohol per day and more. CONCLUSIONS: Our study corroborates gallstones as a risk indicator in extrahepatic biliary tract carcinoma. Permanent overweight and obesity in adult life was identified as a strong risk factor for extrahepatic biliary tract carcinoma, whereas we did not find any strong lifestyle-associated risk factors. Inconsistent results across studies concerning the association of extrahepatic biliary tract carcinoma with overweight and obesity may be explained by the different approaches to assess this variable.
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| 18. |
- Almered Olsson, Gunilla, 1951, et al.
(författare)
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Grass: from local pastures to global energy markets in eastern Tanzania
- 2012
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Ingår i: Ecology and power : struggles over land and material resources in the past, present, and future / edited by Alf Hornborg, Brett Clark and Kenneth Hermele. - Abingdon : Routledge. - 9780415601467 ; , s. 206-216
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Bokkapitel (refereegranskat)
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| 19. |
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| 20. |
- Andersson, Elina, et al.
(författare)
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The Political Ecology of Land Degradation
- 2011
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Ingår i: Annual Review of Environment and Resources. - : Annual Reviews. - 1545-2050 .- 1543-5938. ; 36, s. 295-319
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Forskningsöversikt (refereegranskat)abstract
- Land degradation, as a threat to smallholders in the tropics, attracts less attention than other global challenges. In addition, gaps between scientific understandings of land degradation and international policy regimes are problematic. We identify the three most significant debates including their different policy implications: desertification in the Sahel, nutrient depletion in Africa, and rural reforms in China. Using a political ecology frame across disciplines, scales of inquiry, and regional experiences, we nuance the often polarized scientific debate while seeking to bridge the gap between science and policy. Three main findings emerge: State-led rural reforms in China represent an important approach to land degradation; a renewed focus on agriculture and sustainability in development discourses opens new ways for tackling nutrient depletion with combined sociotechnological reforms; and a policy void in Africa paves the way for market mechanisms, such as payment for environmental services, that are insufficiently understood and put fairness at risk.
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| 21. |
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| 22. |
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| 23. |
- Ardö, Jonas, et al.
(författare)
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Assessment of soil organic carbon in semi-arid Sudan using GIS and the CENTURY model
- 2003
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Ingår i: Journal of Arid Environments. - : Elsevier BV. - 1095-922X .- 0140-1963. ; 54:4, s. 633-651
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Tidskriftsartikel (refereegranskat)abstract
- Using the UNFCCC as a basis, and the objectives of estimating soil organic carbon (SOC) changes during the period 1900-2100, a spatially explicit database of climate, land cover and soil texture was compiled for a 262,000 km(2) region in semi-arid Sudan. The area is characterized by low input cultivation of millet, sorghum and sesame combined with livestock grazing. By integrating the database with the CENTURY ecosystem model, we were able to estimate historical, current and future pools of SOC as a function of land management and climate. The SOC (upper 20 cm) decrease from 1900 to 2000 was estimated to be 6.8 Mt and the maximum potential carbon sink (SOC increase) for the period 2000 to 2 100 was estimated to be 17 Mt. Cropland and grassland lost 293 and 152t SOC km(-2) respectively whereas the savannahs gained 76t SOC km(-2) from 1900 to 2000. The SOC sequestration scenario simulated during 2000-2100 recovered 94, 84 and 75 tkm(-2) for cropland, grassland and savannah respectively. In addition to climate and soils, cropping intensity, fallow periods, fire frequency and grazing intensity also influence cropland SOC variation. Grassland and savannah SOC variations depend on grazing intensity and fire return interval. Land management may affect future amounts of SOC in semi-arid areas thereby turning them from sources into sinks of carbon. SOC estimates were reasonably consistent with measurements (r(2) = 0.70, n = 13).
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| 24. |
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| 25. |
- Ardö, Jonas, et al.
(författare)
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Soil carbon sequestration in traditional farming in Sudanese dry lands
- 2004
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Ingår i: Environmental Management. - : Springer Science and Business Media LLC. - 0364-152X .- 1432-1009. ; 33, s. 318-329
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Tidskriftsartikel (refereegranskat)abstract
- Do altered land management practices offer possibilities to sequester carbon in the soil and thereby mitigate increasing atmospheric CO2 as well as improve local soil fertility? This study investigates the impact of fallow periods on soil organic carbon in semiarid subsistence agroecosystems on sandy and poor soils in Kordofan, Sudan. The area is characterized by low-input cultivation of millet and sorghum in combination with livestock grazing. Recently, cultivation intensity has increased and the fallow periods have been shortened. Soil carbon contents were assessed for sites that have been under various cultivation intensities, ranging from 30 years of fallow to 30 years of continuous cultivation. Soil organic carbon showed a significant negative relationship with cultivation intensity. Measurements indicate a mean increase of approximately 4 g soil organic carbon (SOC) per square meter per year during fallow periods. The possibilities of increasing soil organic carbon by land management were also estimated through simulations using the Century model. Modeling suggested that reverting an intensely cropped millet site to permanent grassland would sequester approximately 1-2 g SOC/m(2)/yr, with higher rates during the early part of the period. Continuous intense cultivation could decrease the currently low soil carbon levels even further. These results indicate that altered land management could contribute to transforming degraded semiarid agroecosystems from a source to a weak sink for atmospheric CO2. Possible data improvements and uncertainties are discussed.
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| 26. |
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| 27. |
- Arneth, Almut, et al.
(författare)
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Restoring Degraded Lands
- 2021
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Ingår i: Annual Review of Environment and Resources. - : Annual Reviews. - 1543-5938 .- 1545-2050. ; 46, s. 569-599
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Forskningsöversikt (refereegranskat)abstract
- Land degradation continues to be an enormous challenge to human societies, reducing food security, emitting greenhouse gases and aerosols, driving the loss of biodiversity, polluting water, and undermining a wide range of ecosystem services beyond food supply and water and climate regulation. Climate change will exacerbate several degradation processes. Investment in diverse restoration efforts, including sustainable agricultural and forest land management, as well as land set aside for conservation wherever possible, will generate co-benefits for climate change mitigation and adaptation and morebroadly for human and societal well-being and the economy. This review highlights the magnitude of the degradation problem and some of the key challenges for ecological restoration. There are biophysical as well as societal limits to restoration. Better integrating policies to jointly address poverty, land degradation, and greenhouse gas emissions and removals is fundamental to reducing many existing barriers and contributing to climate-resilient sustainable development.
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| 28. |
- Asad Ayoubi, Mehran, et al.
(författare)
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Lamellar Microdomains of Block-Copolymer-Based Ionic Supramolecules Exhibiting a Hierarchical Self-Assembly
- 2014
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Ingår i: Macromolecules. - : American Chemical Society (ACS). - 0024-9297 .- 1520-5835. ; 47:10, s. 3428-3435
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Tidskriftsartikel (refereegranskat)abstract
- Based on a parent diblock copolymer of poly(styrene)-b-poly(methacrylic acid), PS-b-PMAA, linear-b-amphiphilic comb (L-b-AC) ionic supramolecules [Soft Matter 2013, 9, 1540-1555] are synthesized in which the poly(methacrylate) backbone of the ionic supramolecular AC-block is neutralized by alkyl (Cn; n = 8, 12, and 16) trimethylammonium counterions (i.e., side chains) at various ion (pair) fractions X [i.e., counterion/side-chain grafting density; X = number of alkyl counterions (i.e., side chains) per acidic group of the parent PMAA block] these L-b-AC ionic supramolecules exhibit a spherical-in-lamellar hierarchical self-assembly. For these systems, (1) the effective Flory-Huggins interaction parameter between L- and AC-blocks chi'(Cn/x) was extracted, and (2) analysis of the lamellar microdomains showed that when there is an increase in X, alkyl counterion (i.e., side chain) length l(sc), or both, there is an increase in both the average interfacial area per block junction Sigma and the thickness of the microlayer of the AC-block d(Ac).
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| 29. |
- Asad Ayoubi, Mehran, et al.
(författare)
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Micro- and nanophase separations in hierarchical self-assembly of strongly amphiphilic block copolymer-based ionic supramolecules
- 2013
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Ingår i: Soft Matter. - : Royal Society of Chemistry (RSC). - 1744-6848 .- 1744-683X. ; 9:5, s. 1540-1555
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Tidskriftsartikel (refereegranskat)abstract
- By a selective complexation between different alkyltrimethylammonium amphiphiles (C8, C12 and C16) and three different diblock copolymer systems of poly(styrene)-b-poly(methacrylic acid) at various grafting densities X (X = number of alkyl chains per acidic group of the poly(methacrylic acid) PMAA block), a class of ionic supramolecules are successfully synthesized whose molecular architecture consists of a poly(styrene) PS block (Linear block) covalently connected to a strongly amphiphilic comb-like block (AmphComb block), i.e. Linear-b-AmphComb. In the melt state, these ionic supramolecules can show simultaneous microphase (between Linear and AmphComb blocks) and nanophase (within the AmphComb blocks) separations. This leads to the formation of various structure-in-structure two-scale hierarchical self-assemblies, including S-in-S-LL, S-in-S-BCC, S-in-C, S-in-L and C-in-L, where S, S-LL, S-BCC, C and L stand for spherical, spherical in liquid-like state, spherical in body-centered-cubic arrangement, cylindrical and lamellar, respectively. Synchrotron small angle X-ray scattering (SAXS) and crossed polarizers, together with SAXS modelling analysis, were used for a detailed structural study of the samples. The morphology of the microphase separated state was mapped out on 'master' microdomain morphology diagrams as a function of the volume fraction of the AmphComb blocks (Phi(AmphComb)) and the compositional window of each microdomain morphology was determined. It was observed that, (i) within samples based on the same parent diblock copolymer system, the occurrence of a specific microdomain morphology is only dependent on the value of Phi(AmphComb), regardless of the grafting density X and the length of the alkyl side-chains, and (ii) microdomain morphological boundaries occur at Phi(AmphComb) values of similar to 0.20 (S-LL/C and S-BCC/C) and similar to 0.28 (C/L). Finally, the specific influences of the strongly amphiphilic nature of the AmphComb blocks on the observed morphological and hierarchical behaviours of our system are discussed. For reference, stoichiometric strongly amphiphilic comb-like (AmphComb) ionic supramolecules, based on complexation between a homopolymer of PMAA and the various alkyltrimethylammonium amphiphiles, were prepared, which nanophase separated into S (C8) or C (C12 and C16) domains.
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| 30. |
- Asad Ayoubi, Mehran, et al.
(författare)
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Morphological Investigation of Polydisperse Asymmetric Block Copolymer Systems of Poly(styrene) and Poly(methacrylic acid) in the Strong Segregation Regime
- 2013
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Ingår i: Journal of Polymer Science. Part B, Polymer Physics. - : Wiley. - 0887-6266. ; 51:23, s. 1657-1671
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Tidskriftsartikel (refereegranskat)abstract
- Samples of compositionally (highly) asymmetric diblock copolymers and, also, mixtures of diblock and triblock copolymers (the latter obtained as end-coupling products of two diblock molecules of the mixture), composed of (a) monodisperse majority block(s) of poly(styrene) (PS) and a polydisperse minority block of poly(methacrylic acid) (PMAA), microphase separate into spherical PMAA microdomains, either in disordered liquid-like state or body-centered-cubic (BCC) arrangement, at various annealing temperatures T, in the strong segregation regime SSR. We found that (i) the microphase separated state is favored over an anticipated molecularly homogenous state, (ii) the spherical microdomain morphology (with BCC symmetry) is favored over an anticipated hexagonally packed cylindrical morphology, (iii) the extent of the dissolution of short PMAA blocks in the PS material can be quantified, (iv) the spherical microdomains are dilated, and (v) despite molecular-weight (and architectural) polydispersity, well-ordered BCC structures can be obtained. (c) 2013 Wiley Periodicals, Inc.
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| 31. |
- Asad Ayoubi, Mehran, et al.
(författare)
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Self-assembly of block copolymer-based ionic supramolecules based upon multi-tail amphiphiles
- 2015
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 5:39, s. 31091-31103
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Tidskriftsartikel (refereegranskat)abstract
- Utilising simple acid-base titration chemistry, a new family of Linear-b-Amphiphilic Comb (L-b-AC) ionic supramolecules [Soft Matter 2013, 9, 1540-1555] featuring multi-tail side-chains have been synthesized and examined by synchrotron SAXS. To three different parent diblock copolymers of poly(styrene)-b-poly( methacrylic acid) PS-b-PMAA multi-tail ammonium side-chains of (C8)(2)-, (C8)(4) -or (C12)(2)-type were attached at various side-chain grafting densities (X), making it possible to separate effects of the details of the AC-block architecture from effects of the overall volume fraction of the AC block. The micro-segregated morphologies of these systems include AC-block filled spherical microdomains in a liquid-like state (SPHLL), AC-block filled hexagonally-packed cylinders (CYL), alternating lamellar microlayers of AC- and L-blocks (LAM) and L-block filled hexagonally-packed cylinders (CYL*). For systems with the same parent diblock copolymer that also carry a constant volume fraction of AC-blocks, an increase in the side-chain length (l(sc)) and/or in the number of alkyl tails at a side-chain branch point (m) result in a microdomain morphology that is either unchanged or changed into one with a less curved interface. For lamellae-forming L-b-AC ionic supramolecules made up of the same parent diblock copolymer, a body of experimental data showing small variations in the repeat distance of the LAM micro-segregated structure (d(LAM)) could be obtained by making appropriate combinations of X, lsc and m. For such lamellae-forming L-b-AC ionic supramolecules, the average of d(LAM) values decreases when l(sc) and/or m increase. For systems with (C12)(2)-type side-chains, the effective Flory-Huggins interaction parameter between L-and AC-blocks chi'(C12)(2)/X was determined at various side-chain grafting densities and it was observed that chi'(C12)(2)/X increases when X is increased.
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| 32. |
- Bai, Z. G., et al.
(författare)
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Proxy global assessment of land degradation
- 2008
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Ingår i: Soil Use and Management. - : Wiley. - 0266-0032 .- 1475-2743. ; 24:3, s. 223-234
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Forskningsöversikt (refereegranskat)abstract
- Land degradation is always With Lis but its causes, extent and severity are contested. We define land degradation as a long-term decline in ecosystem function and productivity, Which may be assessed using lone-term, remotely sensed normalized difference vegetation index (NDVI) data. Deviation from the norm may serve as a proxy assessment of land degradation and improvement - if other factors that may be responsible are taken into account. These other factors include rainfall effects which may be assessed by rain-use efficiency, calculated from NDVI and rainfall. Results from the analysis of the 23-year Global Inventory Modeling and Mapping Studies (GIMMS) NDVI data indicate declining rain-use efficiency-adjusted NDVI on ca. 24% of the global land area with degrading areas mainly in Africa south of the equator, South-East Asia and south China, north-central Australia, the Pampas and swaths of the Siberian and north American taiga; 1.5 billion people live in these areas. The results are very different from previous assessments which compounded what is happening now with historical land degradation. Economic appraisal can be undertaken when land degradation is expressed in terms of net primary productivity and the resultant data allow statistical comparison With other variables to reveal possible drivers.
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| 33. |
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| 34. |
- Bengtsson, Daniel, et al.
(författare)
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Zipper performance when mixing ADSL and VDSL in terms of reach and capacity
- 1997
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this contribution we have examined how the maximum reach vary at different bit rates on a VDSL system, when different numbers of ADSL and VDSL systems share the same binder. In this context it is concluded that when using the Zipper duplex scheme, VDSL can coexist with ADSL in the same binder without a significant degradation in reach. Further, it is shown that the Zipper duplex scheme secure that ADSL is not disturbed by NEXT from VDSL The Zipper performance has also been compared with both a TDD proposal and a FDD proposal. The results from this comparison shows that Zipper outperforms FDD and TDD in terms of extended reach at all studied mixes of ADSL and VDSL sharing the same binder. For example with a moderate number (5) of ADSL disturbers, the Zipper reach is 150 meters longer than for TDD, and is 350 meters longer than for FDD when studying the medium range asymmetrical bit rate (26:3.2 Mbps).
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| 35. |
- Bengtsson, Lars, et al.
(författare)
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Hydrological function of a thin extensive green roof in southern Sweden
- 2005
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Ingår i: Nordic Hydrology. - : IWA Publishing. - 0029-1277. ; 36:3, s. 259-268
-
Tidskriftsartikel (refereegranskat)abstract
- The runoff from and the water balance of a thin extensive green roof with sedum-moss have been studied. The soil cover is about 3 cm underlain by a thin drainage layer. The water balance is determined on a monthly basis. The runoff from the green roof is much reduced compared to runoff from hard roofs because of evapotranspiration. The annual runoff is rather close to that of natural river basins. Although most rainy days there is no or little runoff from the roof, the highest observed daily runoff values are close to the daily rainfall. Runoff is initiated when the soil is at field capacity, which for the studied roof corresponds to 9 mm storage. After that, on a not very short time basis, the runoff equals the precipitation. The reduction of the daily runoff can be described in a simple way knowing the daily precipitation, potential evaporation and storage capacity of the green roof.
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| 36. |
- Biermann, F., et al.
(författare)
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Navigating the Anthropocene: Improving Earth System Governance
- 2012
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 335:6074, s. 1306-1307
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The United Nations conference in Rio de Janeiro in June is an important opportunity to improve the institutional framework for sustainable development.
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| 37. |
- Biermann, F., et al.
(författare)
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The Earth System Governance Project as a network organization : a critical assessment after ten years
- 2019
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Ingår i: Current Opinion in Environmental Sustainability. - : Elsevier BV. - 1877-3435 .- 1877-3443. ; 39, s. 17-23
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Forskningsöversikt (refereegranskat)abstract
- The social sciences have engaged since the late 1980s in international collaborative programmes to study questions of sustainability and global change. This article offers an in-depth analysis of the largest long-standing social-science network in this field: the Earth System Governance Project. Originating as a core project of the former International Human Dimensions Programme on Global Environmental Change, the Earth System Governance Project has matured into a global, self-sustaining research network, with annual conferences, numerous taskforces, research centers, regional research fellow meetings, three book series, an open access flagship journal, and a lively presence in social media. The article critically reviews the experiences of the Earth System Governance network and its integration and interactions with other programmes over the last decade.
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| 38. |
- Biermann, Frank, et al.
(författare)
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Transforming governance and institutions for global sustainability : key insights from the Earth System Governance Project
- 2012
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Ingår i: Current Opinion in Environmental Sustainability. - : Elsevier BV. - 1877-3435 .- 1877-3443. ; 4:1, s. 51-60
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Tidskriftsartikel (refereegranskat)abstract
- The current institutional framework for sustainable development is by far not strong enough to bring about the swift transformative progress that is needed. This article contends that incrementalism-the main approach since the 1972 Stockholm Conference-will not suffice to bring about societal change at the level and speed needed to mitigate and adapt to earth system transformation. Instead, the article argues that transformative structural change in global governance is needed, and that the 2012 United Nations Conference on Sustainable Development in Rio de Janeiro must turn into a major stepping stone for a much stronger institutional framework for sustainable development. The article details core areas where urgent action is required. The article is based on an extensive social science assessment conducted by 32 members of the lead faculty, scientific steering committee, and other affiliates of the Earth System Governance Project. This Project is a ten-year research initiative under the auspices of the International Human Dimensions Programme on Global Environmental Change (IHDP), which is sponsored by the International Council for Science (ICSU), the International Social Science Council (ISSC), and the United Nations University (UNU).
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| 39. |
- Bjurhager, Ingela, et al.
(författare)
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Ultrastructure and Mechanical Properties of Populus Wood with Reduced Lignin Content Caused by Transgenic Down-Regulation of Cinnamate 4-Hydroxylase
- 2010
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Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 11:9, s. 2359-2365
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Tidskriftsartikel (refereegranskat)abstract
- Several key enzymes in lignin biosynthesis of Populus have been down-regulated by transgenie approaches to investigate their role in wood lignification and to explore their potential for lignin modification. Cinnamate 4-hydroxylase is an enzyme in the early phenylpropanoid pathway that has not yet been functionally analyzed in Populus. This study shows that down-regulation of cinnamate 4-hydroxylase reduced Klason lignin content by 30% with no significant change in syringyl to guaiacyl ratio. The lignin reduction resulted in ultrastructural differences of the wood and a 10% decrease in wood density. Mechanical properties investigated by tensile tests and dynamic mechanical analysis showed a decrease in stiffness, which could be explained by the lower density. The study demonstrates that a large modification in lignin content only has minor influences on tensile properties of wood in its axial direction and highlights the usefulness of wood modified beyond its natural variation by transgene technology in exploring the impact of wood biopolymer composition and ultrastructure on its material properties.
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| 40. |
- Bohlooly-Yeganeh, Mohammad, 1966, et al.
(författare)
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Growth hormone overexpression in the central nervous system results in hyperphagia-induced obesity associated with insulin resistance and dyslipidemia.
- 2005
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Ingår i: Diabetes. - 0012-1797 .- 1939-327X. ; 54:1, s. 51-62
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Tidskriftsartikel (refereegranskat)abstract
- It is well known that peripherally administered growth hormone (GH) results in decreased body fat mass. However, GH-deficient patients increase their food intake when substituted with GH, suggesting that GH also has an appetite stimulating effect. Transgenic mice with an overexpression of bovine GH in the central nervous system (CNS) were created to investigate the role of GH in CNS. This study shows that overexpression of GH in the CNS differentiates the effect of GH on body fat mass from that on appetite. The transgenic mice were not GH-deficient but were obese and showed increased food intake as well as increased hypothalamic expression of agouti-related protein and neuropeptide Y. GH also had an acute effect on food intake following intracerebroventricular injection of C57BL/6 mice. The transgenic mice were severely hyperinsulinemic and showed a marked hyperplasia of the islets of Langerhans. In addition, the transgenic mice displayed alterations in serum lipid and lipoprotein levels and hepatic gene expression. In conclusion, GH overexpression in the CNS results in hyperphagia-induced obesity indicating a dual effect of GH with a central stimulation of appetite and a peripheral lipolytic effect.
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| 41. |
- Boisvert, Catherine Anne, 1978-
(författare)
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The Origin of Tetrapod Limbs and Girdles: Fossil and Developmental Evidence
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Around 375 million years ago, the first tetrapods appeared, marking one of the most important events in vertebrate evolutionary history. The fin to limb transition saw the appearance of fingers and a weight bearing pelvic girdle. While very little research has been done on the evolution of the tetrapod pelvic girdle, a fair amount has been done on the origins of fingers but some aspects remained controversial. A combination of palaeontology, developmental biology and comparative morphology was therefore used in this thesis to better understand the fin to limb transition. The pectoral fin of Panderichthys, a sarcopterygian fish closely related to tetrapods was CT-scanned and modeled in three dimensions and its pelvic girdle and fin were examined with traditional techniques. This information from the fossil record was integrated with comparisons of the development of the Australian lungfish, Neoceratodus forsteri, our closest living fish relative and the axolotl (Ambystoma mexicanum), a salamander representing well the condition of early tetrapods. Development of bone and cartilage was studied through clearing and staining and development of skeletal muscles through immunostaining. In situ hybridizations were performed on the lungfish to study the expression of Hoxd13, associated with the formation of digits in tetrapods. This work shows that the late expression phase of Hoxd13 is present in Neoceratodus and is associated with the formation of radials. Redescription of the pectoral fin of Panderichthys reveals that distal radials are present, which, in addition to other information, lead us to conclude that digits are not novelties in tetrapods but rather have evolved from the distal radials present in the fins of all sarcopterygian fish. The earliest tetrapods lack a full set of wrist + carpals/ankle + tarsal bones. Here, we propose that this region of the limbs evolved after fingers and toes through an expansion of the region between the proximal limb bones and the digits. As for the pelvic girdle, it is very primitive in Panderichthys but comparison of its development in Neoceratodus and Ambystoma suggest that the ischium evolved through the posterior expansion of the pubis and the ilium, through an elongation of the iliac process already present in sarcopterygian fishes. The results of this thesis help to better understand the fin to limb transition and show that it is more gradual than previously believed.
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| 42. |
- Borland, Maria, 1967, et al.
(författare)
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Effects of 3months of detraining following cardiac rehabilitation in patients with atrial fibrillation.
- 2022
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Ingår i: European review of aging and physical activity : official journal of the European Group for Research into Elderly and Physical Activity. - : Springer Science and Business Media LLC. - 1813-7253. ; 19
-
Tidskriftsartikel (refereegranskat)abstract
- Atrial fibrillation negatively impacts physical fitness and health-related quality of life. We recently showed that 3months of physiotherapist-led exercise-based cardiac rehabilitation improves physical fitness and muscle function in elderly patients with permanent atrial fibrillation and concomitant diseases. Little is, however, known about the consequences for physical fitness, physical activity level, and health-related quality of life after ending the rehabilitation period.Prospective 3months follow-up study of 38 patients out of 40 eligible (10 women) who, as part of a randomized controlled trial, had completed a 3months physiotherapist-led cardiac rehabilitation resulting in improved physical fitness,. In the current study, the participants were instructed to refrain from exercise for 3months after completion of the rehabilitation period. Primary outcome measure was physical fitness measured as highest achieved workload using an exercise tolerance test. Secondary outcome measures were muscle function (muscle endurance tests), physical activity level (questionnaire and accelerometer), and health-related quality of life, (Short Form-36), as in the preceding intervention study. We used the Wilcoxon Signed Rank test to analyse differences between the end of rehabilitation and at follow-up. The effect size was determined using Cohen's d .Exercise capacity and exercise time significantly decresead between end of rehabilitation and at follow-up (p<.0001 for both). A significant reduction in shoulder flexion repetitions (p=.006) was observed as well as reduced health-related quality of life in the Short Form-36 dimensions Physical Function (p=.042), Mental Health (p=.030), and Mental Component Score (p=.035). There were, however, no changes regarding objective and subjective physical activity measurements.In older patients with permanent atrial fibrillation, previously achieved improvements from physiotherapist-led exercise-based cardiac rehabilitation in physical fitness and muscle function were lost, and health-related quality of life was impaired after ending the rehabilitation period. A strategy for conserving improvements after a rehabilitation period is essential.
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| 43. |
- Borland, Maria, 1967, et al.
(författare)
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Exercise-based cardiac rehabilitation improves physical fitness in patients with permanent atrial fibrillation - A randomized controlled study
- 2020
-
Ingår i: Translational Sports Medicine. - : Hindawi Limited. - 2573-8488. ; 3:5, s. 415-425
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this multicenter randomized controlled trial was to compare physiotherapist-led exercise-based cardiac rehabilitation (PT-X) with physical activity on prescription (PAP) with regard to physical fitness, physical activity, health-related quality of life (HR-QoL), and metabolic risk markers in patients with permanent atrial fibrillation. Ninety six patients (28 women), age 74 (5) years, and ejection fraction >= 45% were randomized. An exercise tolerance test (primary outcome measure), muscle endurance tests, HR-QoL, physical activity assessments (questionnaire and accelerometer), and blood sampling were performed. The PT-X consisted of 60-minute group sessions and home-based exercise, both twice a week. The PAP consisted of 40 minutes of active walking, 4 times a week. Eighty seven patients completed the study. Exercise tolerance (maximum exercise capacity) improved significantly after PT-X (n = 40) but not after PAP (n = 47) (16 vs -3 W; P < .0001). Muscle endurance also improved after PT-X: shoulder flexion left arm (7 vs -1 repetition; P < .001), heel-lift right leg (4 vs 1 repetition; P < .05), left leg (4 vs -1 repetition; P < .001), and shoulder abduction (17 vs -4 s; P < .010). PAP significantly increased energy expenditure. Health-related quality of life and lab-tests did not differ. PT-X improved physical fitness in patients with permanent atrial fibrillation.
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| 44. |
- Bryhn, Andreas, et al.
(författare)
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Fisk- och skaldjursbestånd i hav och sötvatten 2019 : Resursöversikt
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Fisken i havet är en resurs som rör sig fritt över nationella gränser. EU har därför en gemensam fiskeripolitik (GFP). Många arter som är viktiga för Sverige regleras inte i GFP och förvaltas därför nationellt.Denna rapport syftar till att:beskriva utvecklingen av fiskeripolitikenförklara den nuvarande politikens mål och regelverk och dess relation till mål och regler på miljöområdetförklara politikens nationella genomförande och det nationella handlingsutrymmetexemplifiera hur Havs- och vattenmyndigheten arbetat med att reglera fisket.
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| 45. |
- Bråbäck, Lennart, et al.
(författare)
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Childhood asthma and smoking exposures before conception - a three-generational cohort study.
- 2018
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Ingår i: Pediatric Allergy and Immunology. - : Wiley. - 0905-6157 .- 1399-3038. ; 29:4, s. 361-368
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Some human and animal studies have recently shown that maternal grandmother's smoking during pregnancy increases the risk of asthma in the grandchildren. We have investigated whether sex of the exposed parent and/or grandchild modifies the association between grandmaternal smoking and grandchild asthma.METHODS: We formed a cohort study based on linkage of national registries with prospectively collected data over three generations. Smoking habits in early pregnancy were registered since 1982 and purchases of prescribed medication since 2005. In all, 10329 children born since 2005 had information on maternal and grandmaternal smoking on both sides and were followed from birth up to 6 years of age. Ages when medication was purchased were used to classify the cohort into never, early transient (0-3 years), early persistent (0-3 and 4-6 years) and late-onset (4-6 years) phenotypes of childhood asthma.RESULTS: Maternal grandmother's smoking was associated with an increased odds of early persistent asthma after adjustment for maternal smoking and other confounders (odds ratio 1.29, 95% confidence interval 1.10-1.51). Grandchild sex did not modify the association. Paternal grandmother's smoking was not associated with any of the asthma phenotypes.CONCLUSION: Maternal but not paternal exposure to nicotine before conception was related to an increased risk of early persistent childhood asthma, but not other asthma phenotypes. Our findings are possibly consistent with a sex specific mode of epigenetic transfer.
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| 46. |
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| 47. |
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| 48. |
- Buramuge, Victorino Américo, et al.
(författare)
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Exploring Spatial Distributions of Land Use and Land Cover Change in Fire-Affected Areas of Miombo Woodlands of the Beira Corridor, Central Mozambique
- 2023
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Ingår i: Fire. - : MDPI AG. - 2571-6255. ; 6:2
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Tidskriftsartikel (refereegranskat)abstract
- Miombo woodlands (MW) are increasingly experiencing widespread land use and land cover change (LULCC). This study explores the influence of fire, agriculture, and slope variability on LULCC in the miombo of the Beira Corridor. Land use and land cover data were derived from three Landsat images for 2001, 2008, and 2018. Slope attributes were derived from the Shuttle Radar Topography Mission (SRTM). Monthly burned data of Moderate-Resolution Imaging Spectroradiometer (MODIS) were used to map fire frequency. The derived data were then used to investigate the relationship between LULCC and fire, agriculture, and slope, based on geographically weighted regression (GWR). In addition, the relationship between LULCC and slope was assessed. Our findings indicate that fire frequency, agriculture, and slope were significantly spatially non-stationary. We found that LULCC was negatively correlated with agriculture in open miombo, but positively correlated in dense miombo. A positive relationship between LULCC and fire was found for dense and open miombo. Changes in agriculture, dense miombo, and open miombo increased towards high slopes. The study improves the understanding of the spatial effect of LULCC drivers. The development and implementation of effective fire management actions is required to promote sustainable forest management and preservation of critical ecosystem services.
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| 49. |
- Buramuge, Victorino Américo, et al.
(författare)
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Tree Species Composition and Diversity in Fire-Affected Areas of Miombo Woodlands, Central Mozambique
- 2023
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Ingår i: Fire. - : MDPI AG. - 2571-6255. ; 6:1
-
Tidskriftsartikel (refereegranskat)abstract
- Fire strongly impacts the composition and structure of ecosystems, with consequences yet to be understood. We used Moderate Resolution Imaging Spectroradiometer (MODIS) data to map fire frequency and fire intensity and investigate their effects on miombo woodlands (MW) of central Mozambique. Tree species diversity was evaluated and compared using rarefaction curves. Non-metric multidimensional scaling (NMDS) ordination was used to identify patterns of species composition occurrence. The indicator value index method was applied to verify the occurrence of fire indicator species. In general, tree communities responded differently to varied fire regimes. We found low tree density in Intermediate fire frequency and intensity (IfIi) (180 trees ha−1) and High-frequency and Low intensity (HfLi) (316 trees ha−1) areas. The IfIi fire regime had the lowest carbon stocks (9.1 Mg ha−1), when compared to the rest of fire regimes. The species diversity decreased as fire intensity increased. IfIi areas had the maximum species diversity. The NMDS showed a varied species composition according to fire regime. We found a strong relationship between the species diversity and composition, and the pattern of fire occurrence in each fire regime. Our results are critical in supporting fire management policies and understanding fire regimes and their effects on miombo trees’ structure and composition.
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| 50. |
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