| 1. |
- Westerberg, Håkan, et al.
(författare)
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Properties of odour plumes from natural baits
- 2011
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Ingår i: Fisheries Research. - : Elsevier BV. - 0165-7836. ; 110:3, s. 459-464
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Tidskriftsartikel (refereegranskat)abstract
- The formation of an odour trail can be broken down into a chain of events: first, the emission of the attractant from the bait, second, a turbulent mixing into the immediate surroundings and third, a downstream advection and dispersion of the attractant by the current flowing past the bait. In this work, a simple analysis of the physical processes governing the first two stages shows that the release of attractant will decline as the inverse of the square root of time. The decline curve will be similar for all solid natural baits within a realistic size range during normal soak times. Experiments were performed to measure typical diffusion constants of odour substances in fish tissue and it is shown that due to the low diffusivity just a thin surface layer will release its content of odour substances during a fishing operation using pieces of fish as bait. Moreover, the initial concentration of attractant when a plume is formed will be independent of the size of a solid bait and only depend on the ratio of the surface area to the cross-section area of the bait. To increase the maximum concentration of odour substance in the plume and utilize a given amount of bait optimally, a solid bait should be cut into smaller pieces. The effect of current speed on the initial odour concentration in the plume is strong. Due to speed variations during the soak time the effectiveness of the attraction will vary in time. To extend the analysis and develop models for optimization of the range of the olfactory signal from a bait it is necessary to know both the concentration of the attractant in the bait and the target species detection threshold. When such data become available it will be possible to estimate the range of attraction of baits under different environmental conditions.
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| 2. |
- Axelsson, Karin, et al.
(författare)
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Entrepreneurship in teacher education : Conceptualisation and tensions
- 2018
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Ingår i: Entrepreneurship, Innovation and Education. - cheshire : Edward Elgar Publishing. ; , s. 123-145
-
Bokkapitel (refereegranskat)abstract
- Entrepreneurship education is an area of growing importance within entrepreneurship research. This book critically discusses innovation and entrepreneurship in new and varied contexts in Europe. Entrepreneurship, Innovation and Education explores the need for researching innovation and learning in family firms, micro firms, SMEs and in rural and network contexts. The chapters offer new insights into the antecedents of business performance in SMEs by investigating social capital and marketing capabilities. The book includes a new typology for analysing entrepreneurship education programmes, discusses opportunities for embedding entrepreneurship in teacher education and explores entrepreneurship in the informal learning arenas in universities. This book includes a wide range of studies from different analytical and methodological perspectives and from various regional and industrial contexts. As such, it is a valuable tool for advanced students of European entrepreneurship. Researchers in entrepreneurship will also benefit from the up-to-date research analysis in this book.
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| 3. |
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| 4. |
- Axelsson, Karin, et al.
(författare)
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Entrepreneurship in Teacher Education - Conceptualization, Design & Learning outcomes
- 2016
-
Ingår i: RENT XXX, Antwerpen, Belgium, 18-19 November, 2016.
-
Konferensbidrag (refereegranskat)abstract
- Objectives: Currently some novel initiatives in Sweden aim to introduce entrepreneurship broadly in teacher education programs. The purpose of this paper is to shed light on one of these early attempts. Specifically we will answer the following research questions: How is entrepreneurship conceptualized in teacher education programs? How is the education designed in terms of pedagogy and didactics? What are the main learning outcomes that the education strives for?Literature review: The broadening of the entrepreneurship concept where entrepreneurship is conceptualized as a general method for human development (Sarasvathy & Venkataraman, 2011) as well as the proposition by Hannon (2013) that entrepreneurism is the development of a set of individual behaviors, skills and attitudes can be applied in many societal contexts, has provided openings to work with entrepreneurship in teacher education. However in relation to entrepreneurship education we still lack knowledge on key educational and didactical issues, in terms of for instance the nature and impact of our activities (Fayolle, 2013) and in relation to teacher education programs this knowledge is even more scarce.Approach: In this mainly qualitative case study of a Swedish teacher education entrepreneurship module we apply interviews and surveys of both teachers and students to collect our empirical material. Our starting point is that entrepreneurship education activities in this setting needs to be underpinned by thoughts on theoretical concepts and practices from both entrepreneurship and learning theories. We use Fayolle and Gaillys (2008) teaching model framework as an analytic lens to help provide necessary understanding in relation to our pedagogical and didactical questions.Results: The results show how entrepreneurship education in teacher education is riddled with tensions relating to overall mission, target groups, pedagogy, content and assessments. However, there seem to be viable paths forward that might mitigate these tensions and provide a better opportunity for entrepreneurship education within the realm of teacher education.Implications and Value: First and foremost, we add to the knowledge about how entrepreneurship is introduced in teacher education programs, helping both researchers and practitioners understand the conceptualization, design in terms of pedagogy and didactic, as well as main learning outcomes. By using and building on Fayolle and Gailly’s (2008) theoretical teaching model framework, we provide structured empirical perspectives and knowledge aggregation on pedagogy and didactic in entrepreneurship education. As such we contribute to the knowledge about how entrepreneurship education is operationalized and perceived in a special case of non-business context, from both a teacher and student perspective.
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| 5. |
- Borg, Niklas, et al.
(författare)
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Effects of uncertainties in experimental conditions on the estimation of adsorption model parameters in preparative chromatography
- 2013
-
Ingår i: Computers & Chemical Engineering. - : Elsevier BV. - 1873-4375 .- 0098-1354. ; 55, s. 148-157
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Tidskriftsartikel (refereegranskat)abstract
- Model-based process design is increasingly popular when designing pharmaceutical purification processes. The effect of uncertainties in concentration measurements on the estimation of model parameters is analyzed for two cases of non-isocratic adsorption chromatography. A model, calibrated to experiments, is used to generate data by adding a Monte Carlo sampled error in the inlet concentrations. New model parameters are estimated by minimizing the deviation between the synthetic data and the model. The first case is a separation of rare earth elements by ion-exchange chromatography and the second case is a purification of insulin from a product-related impurity by reversed-phase chromatography. It is shown that normally distributed errors in the concentrations result in deviations in the UV-signal that are not normally distributed. With the applied method, known concentration distributions can be translated into probability distributions of the model parameters, which can be taken into account in the model-based process design. (C) 2013 Elsevier Ltd. All rights reserved.
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| 6. |
- Borg, Niklas, et al.
(författare)
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Modeling and robust pooling design of a preparative cation-exchange chromatography step for purification of monoclonal antibody monomer from aggregates.
- 2014
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Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673. ; 1359, s. 170-181
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Tidskriftsartikel (refereegranskat)abstract
- This study has implemented and calibrated a model that describes the separation of the monomer of monoclonal antibodies from the dimer and larger oligomers on preparative-scale using cation-exchange chromatography. A general rate model with temperature dependent diffusion was coupled to a pH- and temperature-dependent steric mass action model. The model was shown to predict the retention of the monomer, dimer, and oligomer at low loadings for different pH levels and temperatures. Additionally, the model was shown to adequately predict the elution behavior of the monomer and soluble aggregates at high loadings within the same ranges with some limitations. The model was not able to accurately describe the shape of the product break-through curves or the slight levels of co-elution of the dimer and oligomer with the monomer at higher pH. The model was used to predict how 12 process variations impact the separation. The model is used to establish an elution end collection criterion such that the step can robustly provide the target purity of monomers.
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| 7. |
- Danestig, Maria, 1965-, et al.
(författare)
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A multidisciplinary and interactive method for exploring energy systems in municipalities
- 2009
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Due to environmental concerns and changed market conditions in the energy system, the preconditions for energy use and production in Sweden have changed in recent years. To be able to manage these new demands on a local level, municipalities need to adopt new methods to deal with unstructured and complex situations. This article presents a method for multidisciplinary and interactive exploration of energy systems at the local level. The method creates opportunities for local actors to discuss and negotiate the necessary actions within the local energy system.
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| 8. |
- Danestig, Maria, 1965-, et al.
(författare)
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Att förändra ett uppvärmningssystem : bilder av framtidens energisystem i Söderköping
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rapporten bygger på en fallstudie i Söderköpings kommu och sätter bilder av framtidens uppvärmningssystem och dessa bilders betydelser för lokalt förändringsarbete i fokus. I fallstudien ingår intervjuer med 4 kommunpolitiker, 4 kommunal tjänstemän samt 2 representater för det privata fjärrvärmeföretaget. Dessutom studeras kommunal protokoll samt massmedierapporteringen kring uppvärmningen i Söderköping. Centrala frågor är: Hur tolkar lokala aktörer tidigare förändringar?; Hur påverkar dessa tolkningar aktörernas bilder av framtidens uppvärmningssystem?; Vilka förhoppningar och farhågor knyts till framtiden?; samt Hur kan lokala framtidsbilder omformas till scenarier och hur kandessa scenarier användas i det kommande energiarbetet i kommunen? Rapportens bärande kategorier är historier, framtidsbilder och scenarier. Med historier menas de berättelser om tidigare förändringar som återfinns i massmedia och kommunala protokoll, men också i informanternas intervjuer. Framtidsbilder utgörs av de förhoppningar och farhågor kring den framtida utvecklingen av uppvärmningssystemet som förmedlats via intervjuerna. Med scenarier menas slutligen de renodlingar och utvecklingar av centrala drag i framtidsbilderna som forskarna stått för och som utvecklats till diskussionsunderlag för kommande energiarbete i kommunen. De scenarier som presenteras och diskuteras är: Centraliserade biobränslesystem Värmepumpskommunen, samt Den decentraliserade självhushållningen
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| 9. |
- Danestig, Maria, 1965-, et al.
(författare)
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Lokala aktörers visioner : Framtidens uppvärmningssystem i en kommun
- 2005
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Ingår i: Energitinget,2005. ; , s. 30-30
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Den situation som olika aktörer Söderköping står inför då det gäller uppvärmningssystemet fokuseras i den studie som presenteras. Huvudsyftet med arbetet har varit att studera aktörernas uppfattning om hur uppvärmningssystemet kan utvecklas samt vilka lokala scenarier som kan skapas. Studien belyser frågor som vilka hinder och möjligheter som finns för uppvärmningssystemets utveckling givet lokala förutsättningar samt hur olika aktörers inflytande skiftar i olika utvecklingsmöjligheter. Presentationen bygger på rapporten "Att förändra ett uppvärmningssystem: bilder av framtidens uppvärmningssystem i Söderköping"
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| 10. |
- Degerman, Marcus, et al.
(författare)
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A Model-Based Approach to Determine the Design Space of Preparative Chromatography
- 2009
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Ingår i: Chemical Engineering & Technology. - : Wiley. - 1521-4125 .- 0930-7516. ; 32:8, s. 1195-1202
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Tidskriftsartikel (refereegranskat)abstract
- A dream of many pharmaceutical companies is to be able to register a large design space with the regulatory agencies. The problem is that this will require both time and money, so an intelligent method of validating a design space is needed. The design space should only cover operating points at which the process runs optimally. This means that the process should be optimized for different process scenarios and objective functions and the found operating points should be registered as design space. This paper presents a method of determining a good design space by creating Pareto fronts for the ideal case and for various process disturbance scenarios. Optimal operating points are found for varying ratios between feed costs and operating costs, making it possible to make a quantitative choice of an operating point based on this ratio and a qualitative choice based on the whole front. The analysis will show how the chromatographic process can be made more robust when optimizing for higher yields, and how the effect of the critical process parameters can change. To be certain that a robust process is found and that it has a high performance, process disturbances must be taken into account when optimizing a process.
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| 11. |
- Degerman, Marcus, et al.
(författare)
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Determining Critical Process Parameters and Process Robustness in Preparative Chromatography - A Model-Based Approach
- 2009
-
Ingår i: Chemical Engineering & Technology. - : Wiley. - 1521-4125 .- 0930-7516. ; 32:6, s. 903-911
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a model-based method to aid in the process validation for the purification of pharmaceutical drugs. The critical process parameters are identified by simulating process disturbances, and this information is then used to determine if the process control space is robust. Simulations are chosen to analyze the entire control space to also find nonlinearities and interaction effects between the process disturbances, which are used to determine where in the control space the critical quality attributes are the lowest, i.e., the worst case scenario. The real process conditions are estimated by running simulations according to plausible probability distributions using Latin hypercube sampling. The probability of batch failure can be estimated from this and it is shown that the worst case scenario is improbable for most cases. This information can help in planning validation experiments or determine which critical process parameters need a tighter control. Three case studies are used to illustrate the usefulness of the methods. It was found that the main critical process parameters in all three case Studies were variations in the modifier concentrations, for example, salt in ion-exchange chromatography and hydrophobic interaction chromatography, and the organic modifier in reversed-phase chromatography.
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| 12. |
- Enoksson, Mattias, et al.
(författare)
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Intraperitoneal influx of neutrophils in response to IL-33 is mast cell-dependent
- 2013
-
Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 121:3, s. 530-536
-
Tidskriftsartikel (refereegranskat)abstract
- IL-33 is a recently discovered cytokine involved in induction of Th2 responses and functions as an alarmin. Despite numerous recent studies targeting IL-33, its role in vivo is incompletely understood. Here we investigated inflammatory responses to intraperitoneal IL-33 injections in wild-type and mast cell–deficient mice. We found that wild-type mice, but not mast cell–deficient Wsh/Wsh mice, respond to IL-33 treatment with neutrophil infiltration to the peritoneum, whereas other investigated cell types remained unchanged. In Wsh/Wsh mice, the IL-33–induced innate neutrophil response could be rescued by local reconstitution with wild-type but not with T1/ST2−/− mast cells, demonstrating a mast cell–dependent mechanism. Furthermore, we found this mechanism to be partially dependent on mast cell–derived TNF, as we observed reduced neutrophil infiltration in Wsh/Wsh mice reconstituted with TNF−/− bone marrow–derived mast cells compared with those reconstituted with wild-type bone marrow–derived mast cells. In agreement with our in vivo findings, we demonstrate that humanneutrophils migrate toward the supernatant of IL-33–treated human mast cells. Taken together, our findings reveal that IL-33 activates mast cells in vivo to recruit neutrophils, a mechanism dependent on IL-33R expression on peritoneal mast cells. Mast cells activated in vivo by IL-33 probably play an important role in inflammatory reactions.
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| 13. |
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| 14. |
- Holmgren, Karin, et al.
(författare)
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The vulnerable continent (PLATINA) : Historical perspectives on Africa´s climate, environment and societies
- 2009
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Ingår i: Meeting global challenges in research cooperation. - Uppsala : Uppsala University. - 9789197574198 ; , s. 585-596
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Konferensbidrag (refereegranskat)abstract
- Our research, based on studies of different climate archives from Tanzania, Mozambique and South Africa, contributes information on changes in climate and vegetation over the past 24000 years. This time perspective, reaching beyond the information available from instrumental records is needed for a better understanding of regional global climate dynamics and issues surrounding environmental change, throughout Africa, and is a prerequisite for increasing climate forecasting capabilities for the region. We argue that African people have vast experience from living in a variable climate and research on past interactions between climate and societies demonstrate the significance of lessons learnt for present situations. Our findings, underline the complex interactions between climate/environment and societies that may lead to different developments in time and space. Considering the so called vulnerable continent, extended investigations of how African communities cope with and adapt to climatically driven changes is needed to increase the capability to realise the potential as well as the limitations, of modern African communities to adapt to future climate change.
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| 15. |
- Hugelius, Karin, 1977-, et al.
(författare)
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Swedish ambulance managers descriptions of crisis support for ambulance staff after potentially traumatic events
- 2014
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Ingår i: Prehospital and Disaster Medicine. - : Cambridge University Press. - 1049-023X .- 1945-1938. ; 29:6, s. 589-592
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Tidskriftsartikel (refereegranskat)abstract
- Introduction:Ambulance staff face complex and sometimes stressful or potentially traumaticsituations, not only in disasters but also in theirroutine daily work. The aim of this study wasto survey ambulance managers’ descriptions of crisis support interventions for ambulance staffafter potential traumatic events (PTEs).Methods:Semistructured interviews with a qualitative descriptive design were conductedwith six ambulance managers in a health care region in central Sweden. The data wasanalyzed using content analysis.Result:Five categories were found in the result: (1) description of a PTE; (2) descriptionand performance of crisis support interventions; (3) impact of working in potentiallytraumatic situations; (4) the ambulance managers’ role in crisis support interventions;and (5) the ambulance managers’ suggestions for improvement.Ambulance managersdescribed crisis support interventions after a PTE as a single, mandatory group meetingwith a structure reminiscent of debriefing. The ambulance managers also expressed doubtsabout the present structures for crisis support and mentioned an alternative approachwhich is more in line with present evidence-based recommendations.Conclusion:The results indicated a need for increased understanding of the importanceof the managers’ attitudes for ambulance staff; a need for further implementation ofevidence-based recommendations for crisis support interventions was also highlighted.
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| 16. |
- Hultman, Martin, 1976-, et al.
(författare)
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Den intersektionella energibranschen?
- 2005
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Ingår i: Intersektionalitet: Ett användbart begrepp inom genusforskningen 4:e nationella genusforskningskonferensen,2005.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- I papret görs en första "omläsning" av såväl tidigare studier som ett pågående avhandlingsprojekt kring kommunalt energiarbete utifrån begreppet intersektionalitet. Utgångspunkten är den samtida konstruktionen av expertis och maskulinitet inom det kommunala energiarbetet och ett första - tentativ - försök att förstå detta också utifrån interaktionen mellan kön, klass, utbildning och etnicitet.
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| 17. |
- Ivner, Jenny, 1976-, et al.
(författare)
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Energiplanering i Östergötland : Ett samverkansprojekt för att stötta framtagande av kommunala energiplaner/klimatstrategier : Slutrapport
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Projektet Energiplanering i Östergötland, som pågick under 2009 och 2010, genomfördes som ett samverkansprojekt mellan 8 mindre kommuner i Östergötland, Regionförbundet Östsam och Linköpings universitet. Projektets syfte var att ge kommunerna stöd i att ta fram energiplaner, med målet att alla Östergötlands kommuner skulle ha en aktuell plan efter projektets slut. Genom projektet har kommunerna haft tillgång till olika typer av stöd, från workshopar till beräkningsverktyg. Kommunerna har valt att organisera sitt arbete på olika sätt; några har organiserat arbetsgrupper ledda av en tjänsteman, andra har valt att tillfälligt anställa energi- och klimatrådgivaren eller en extern konsult för att leda processen. Alla kommuner utom en har uppnått projektets mål och har ett utkast till, eller antagen, energiplan vid projekttidens slut. Den kommun som inte nått ända fram, står nu i beredskap att inleda en planeringsprocess. Författarna av denna rapport har identifierat följande förutsättningar som lyckosamma för genomförandet av en energiplaneringsprocess: • Engagerade chefstjänstemän som förfogar över tid och resurser till projektet • Det finns redan ett engagemang i kommunen för energifrågor och/eller vana att arbeta strategiskt i andra projekt• Tillgång till en engagerad och kunnig person i form av energi- och klimatrådgivare eller konsult som kan stötta arbetet • Stöttning från nätverk och den regionala nivån med kompetens, verktyg och processtöd. Ett antal mindre gynnsamma omständigheter och risker har också identifierats: • Låg kunskap om energifrågor i den egna organisationen • Inga extra resurser tilldelas det energistrategiska arbetet• Låg kvalitet på de kommunala energibalanserna som finns i den nationella statistiken och ovilja från energiföretag och industri att lämna ut statistikuppgifter • Konsulter/energi- och klimatrådgivare drar det största lasset i energiplaneringen, vilket innebär begränsad insyn/påverkansmöjlighet och risk för att viktig kunskap inte stannar i den kommunala organisationen. Baserat på erfarenheterna från projektet ges följande rekommendationer: • Personella resurser måste avsättas inom kommunen även om man tar hjälp av konsulter under arbetet. Den kommunala organisationen måste bygga upp kunskap inom energi- och miljöområdet om man ska följa med i utvecklingen och leva upp till energipolitiska mål. • Redan under arbetet med energiplanen måste planering för implementerings- och uppföljningsarbete göras. För detta krävs ett aktivt arbeta för att integrera energifrågorna i det dagliga arbetet och i kommunens årliga uppföljningsrutiner. • Stöttning av mindre kommuners energiplaneringsarbete från regionalt håll, till exempel med sammanställning av datamaterial för nulägesanalys och uppföljning, underlättar lokal kompetensutveckling. Slutligen, formuleringen av en energiplan är bara början på det energistrategiska arbetet. Det är först när energifrågorna har en självklar och viktig plats i det vardagliga arbetet på kommunen som man kan göra stora förändringar.
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| 18. |
- Ivner, Jenny, 1976-, et al.
(författare)
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Approaches to participation in local energy-planning : Examples from a swedish region
- 2010
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Ingår i: Proceedings of the 2010 ERSCP-EMSU Conference In Delft & Cape Town October 25-29.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a study in which ten small local authorities were asked how they would like to approach local stakeholders in their energy-planning. Based on the answers this paper discusses participation in an energy-planning context and shows how goals and methods may differ according to the different target groups the local authorities wish to reach. The different approaches to stakeholder participation are then categorised into four categories – participation as capacity building, participation as a way to create acceptance, participation as a way to change behaviour and participation as partnership building – and discussed in relation to participation literature.
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| 19. |
- Lindqvist, Anna-Karin, et al.
(författare)
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Moving From Idea to Action : Promoting Physical Activity by Empowering Adolescents
- 2014
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Ingår i: Health Promotion Practice. - : SAGE Publications. - 1524-8399 .- 1552-6372. ; 15:6, s. 812-818
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Tidskriftsartikel (refereegranskat)abstract
- Background. Physical activity provides fundamental health benefits for children and youth. The aim of the study was to explore the possibility of conducting an empowerment-inspired intervention and examine the impact of the intervention in promoting moderate and vigorous physical activity (MVPA) among adolescents. Method. A nonrandomized trial with a concurrent control group was carried out. Physical activity data were collected before and after the intervention with daily questions by short message service. Self-efficacy, social support, and attitude were also measured before and after the intervention since they were possible mediators. Results. The intervention was created by the students, the researchers, and the teachers using an empowerment-based approach. Students in the intervention group (n = 21) increased their MVPA on average by 4.9 (SD = 28.9) minutes per day, and students in the control group (n = 25) reduced their MVPA on average by 25.4 (SD = 23.0) minutes per day (p = .000). Conclusions. The intervention might have contributed to a promotion of physical activity among students in the intervention group. The most valuable contribution this study provides is the knowledge that it is possible to develop and conduct an empowerment-inspired intervention to promote adolescent physical activity.
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| 20. |
- Ling, Erik, et al.
(författare)
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Mot ett hållbart energisystem : Fyra förändringsmodeller
- 2001
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Syftet med denna studie är att undersöka hur förändringsprocesser mot ett hållbart energisystem går till i verkligheten. Fokus läggs på strategiska förändringsprocesser inom den kommunala sektorn och på att identifiera centrala drag som är avgörande för förändringsprocessens resultat.
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| 21. |
- Ling, Erik, et al.
(författare)
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Mot ett hållbart energisystem: fyra förändringsmodeller : huvudrapport
- 2002
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The public sector in Sweden has charged its institutional structures with a new goal for societal development under the rubric "The Sustainable Sweden". This has been the result of international agreements that Sweden has entered into and domestic debates concerning the need for a sustainable development. The interaction between the public sector and the development of the energy system has entered a new phase. At the same time market reorientation has radically changed the public sector's possibilities to directly control the implementation of the sustainability goals in the energy system. Influence through ownership and the direct political control that this entailed has more or less been voluntarily phased out during recent years by governmental and municipal organizations. The desire for a change towards sustainable development has, however, meant that the public sector needs new ways to initiate, push for or support processes of change within the energy system in its new, multifaceted shape. Therefore in this study we focus on the energy sector and the possibilities to development steering methods for a sustainable energy system by: - Studying processes of change in different parts of the energy system with the purpose of identifying different forms for strategic change, - Describing the pressures, barriers and possibilities which are made visible in these processes, - Discussing and developing methods for managing and steering the processes of change.
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| 22. |
- Lisberg Jensen, Ebba, et al.
(författare)
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Through Internet and Friends : Translation of Air Pollution Research in Malmö Municipality, Sweden
- 2020
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI. - 1661-7827 .- 1660-4601. ; 17:12
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Tidskriftsartikel (refereegranskat)abstract
- Air pollution is estimated to cause more than 7000 deaths annually in Sweden alone. To reduce the impact of air pollution and to plan and build sustainable cities, it is vital that research is translated into efficient decisions and practice. However, how do civil servants in a municipality access research results? How do they normally find relevant information, and what obstacles are there to accessing and applying research results? As part of the collaborative and transdisciplinary research project Air Pollution Research in Local Environmental Planning (ARIEL), these questions were explored through interviews and seminars with civil servants within the Malmö Municipality Environmental Office. We found that the civil servants generally have proficiency in processing research results, but often do not use such results as part of their everyday decision making and practices. Instead, the data and measurements used are mostly produced case-by-case within the municipal sector itself. Information about best practices is also collected via a number of knowledge access practices, involving the Internet or social networks within other municipalities. Lack of time, paywalls, and the insufficient applicability of research hinder the dissemination of up-to-date results. This slows down the process whereby research, funded by tax-money, can be put to best practice in the effort to create healthy and sustainable cities.
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| 23. |
- Malmqvist, Ebba, et al.
(författare)
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Estimated health benefits of exhaust free transport in the city of Malmö, Southern Sweden
- 2018
-
Ingår i: Environment International. - : Elsevier. - 0160-4120 .- 1873-6750. ; 118, s. 78-85
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Tidskriftsartikel (refereegranskat)abstract
- Luftföroreningar står för ett av åtta förtida dödsfall i världen, och utgör därmed ett stort hot mot människors hälsa. HIA (hälsokonsekvensbedömningar) av hypotetiska förändringar i luftföroreningshalter kan användas som ett sätt att bedöma hälsoeffekter, planer och projekt som beslutsfattare behöver för att förhindra sjukdom. Syftet med denna studie var att beräkna hälsoeffekter som kan tillskrivas hypotetisk nedgång i luftföroreningshalter i Malmö i södra Sverige om en policy med avgasfri innerstad skulle genomföras.
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| 24. |
- Mårtensson, Kjell, et al.
(författare)
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Corporate environmental strategies towards sustainable development
- 2016
-
Ingår i: Business Strategy and the Environment. - : John Wiley & Sons. - 0964-4733 .- 1099-0836. ; 25:1, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Många företag arbetar utifrån någon form av miljöstrategi för att hantera sina relationer till naturen. I många fall är dock dessa miljöstrategier frånkopplade från företagets övriga strategiska arbete vilket leder till att det miljöstrategiska arbetet inte blir effektivt. Artikelns syfte är att utforska olika sätt på vilka effektiva miljöstrategier kan utvecklas inom företag. Utifrån ett resursperspektiv, lyfter vi fram materialflöde, kunskap och erfarenhet, relationer, kommunikation och kontroll som viktiga aspekter i en effektiv miljöstrategi. Med hjälp av dessa fem aspekter visar vi hur tre olika miljöstrategier, med olika innehåll och riktningar, kan utvecklas.
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| 25. |
- Mårtensson, Kjell, et al.
(författare)
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How to transform local energy systems towards bioenergy? Three strategy models for transformation
- 2007
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Ingår i: Energy Policy. - : Elsevier BV. - 0301-4215 .- 1873-6777. ; 35:12, s. 6095-6105
-
Tidskriftsartikel (refereegranskat)abstract
- During the last decades, the actors within the energy sector in Sweden-as well as in many other countries-have faced increasing demands to transform the energy system towards ecological sustainability. In Sweden these demands have led to numerous policies and economic incentives promoting the use of renewables (which in the Swedish discourse often also includes a connotation of "indigenous energy sources"), and especially the promotion of bioenergy. To be successful, however, these policies and economic incentives need to be interpreted and adapted to different local contexts and translated into actual transformation processes. In Sweden the municipal authorities have played an important role as interpreters of such institutional frameworks and implementers of local transformation processes. In this article, we re-construct three transformation processes implemented by local municipal authorities, chiselling out the different strategy models developed through them. We argue that such re-constructions help to make visible the different and complex interactions between national institutional frameworks and local contexts as well as interactions within such local contexts. We hope that the strategy models presented can contribute to the understanding of the different kinds of local actions that can foster a further implementation of bioenergy into the energy system. © 2007 Elsevier Ltd. All rights reserved.
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| 26. |
- Pantazis, Antonios, et al.
(författare)
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Harnessing photoinduced electron transfer to optically determine protein sub-nanoscale atomic distances
- 2018
-
Ingår i: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- Proteins possess a complex and dynamic structure, which is influenced by external signals and may change as they perform their biological functions. We present an optical approach, distance-encoding photoinduced electron transfer (DEPET), capable of the simultaneous study of protein structure and function. An alternative to FRET-based methods, DEPET is based on the quenching of small conjugated fluorophores by photoinduced electron transfer: a reaction that requires contact of the excited fluorophore with a suitable electron donor. This property allows DEPET to exhibit exceptional spatial and temporal resolution capabilities in the range pertinent to protein conformational change. We report the first implementation of DEPET on human large-conductance K+ (BK) channels under voltage clamp. We describe conformational rearrangements underpinning BK channel sensitivity to electrical excitation, in conducting channels expressed in living cells. Finally, we validate DEPET in synthetic peptide length standards, to evaluate its accuracy in measuring sub-and near-nanometer intramolecular distances.
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| 27. |
- Ryner, Maria, 1967-
(författare)
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Past environmental and climate changes in northern Tanzania : Vegetation and lake level variability in Empakaai Crater
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis presents palaeoenvironmental data from equatorial Africa covering two important time intervals; i) the warming period forming the Pleistocene/Holocene transition and ii) the last millennium. The Empakaai Crater, in northern Tanzania contains a lake from where sediment cores, spanning two time-slices 14.8-9.3 ka and 800-2000 AD, have been studied. Palaeoecological and palaeohydrological reconstruction is based on a multitude of proxies from the sediments, representing both catchment environment and the lakes aquatic ecosystem response. Between 14.8 and 10 ka the catchment vegetation and lake hydrology responded to both regional climate changes and local environment, but with different amplitude and frequency, reflecting temporal and spatial lags between the two systems. However, at c 10 ka both lake conditions and catchment vegetation showed drastic changes towards drier conditions. The record covering the last millennium reveals environmental changes related to climate and human activities. The catchment’s vegetation was affected by frequent fires, most probably human induced, while near shore vegetation responded to lake level fluctuation associated with rainfall variability. About 15 km from Empakaai Crater is an extensive abandoned irrigation system, the Engaruka complex, which was in active use between c 1400 AD and 1840 AD. By comparing a number of social and environmental factors potentially influencing the societal development at Engaruka it is shown that wet climate conditions have had positive effects on the societal development but also that dry climate conditions were not always disastrous to the society. The resemblance of the pollen taxa present is strong between the two time slices and pollen representing catchment conditions respond in similar manner in both records. The lake conditions are however very different between the two periods Thus the lake responds to both long and short term changes of variable amplitude, while the catchment vegetation seems to responds to high amplitude, low frequency changes.
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| 28. |
- Samuelsson, Ulf, et al.
(författare)
-
Geographical variation in the incidence of type 1 diabetes in the Nordic countries : A study within NordicDiabKids
- 2020
-
Ingår i: Pediatric Diabetes. - : Blackwell Publishing. - 1399-543X .- 1399-5448. ; 21:2, s. 259-265
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The incidence of type 1 diabetes (T1D) is high in the Nordic countries with geographic differences between as well as within countries. Objective: To describe the geographical distribution of the incidence of T1D among children in four Nordic countries, an area where the population is considered genetically similar.Methods: Data on children 0 to 14 years of age and diagnosed with T1D 2006 to 2011 was collected from four Nordic national pediatric quality diabetes registries. Data included year of diagnosis (2006-2011), sex, and age at diagnosis. Figures for number of children at risk during 2006 to 2011—as well as total population, proportion with foreign background and size of populated areas of geographic regions—were collected from official statistics.Results: The total incidence during the study period for all four countries was 35.7/100 000 person years but differed between the countries (range 18.2-44.1; P <.001). The incidence difference between the countries was most obvious in the highest age group, 10 to 14 years of age, whereas there was no difference in the youngest age group 0 to 5 years of age. Iceland had similar incidence in the entire country, whereas the other countries had areas with different incidence. Densely populated areas, such as major cities, had the lowest incidence.Conclusion: The incidence of T1D differed between the Nordic countries and also between the neighboring countries and generally decreased with population density. This indicates that environmental factors may contribute to the level of incidence of T1D.
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| 29. |
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| 30. |
- Westerberg, Ida, et al.
(författare)
-
Utveckling av indata för belastningsberäkningar med avseende på kvalitet och skala inklusive delning av produktionsområde 6
- 2013
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Den mängd näringsämnen som transporteras från Sveriges yta och belastar havet utgör ett viktigt beslutsunderlag för nationell och internationell vattenförvaltning. Den mest omfat-tande beräkningen av kväve- och fosforbelastningen på havet, Pollution Load Compilat-ion (PLC) periodical, utförs med 5–6 års mellanrum. Beräkningarna utfördes senast för år 2006 (PLC5). Nästkommande PLC Periodical-rapportering, PLC6, kommer att utföras för år 2014 och det är föreslaget att beräkningarna ska utföras med en högre geografisk upplösning (vattenförekomst) än de tidigare PLC5-beräkningarna (delavrinningsområde).Resultaten från PLC5 används inom den lokala vattenförvaltningen för delavrinningsom-råden, även om de från början var avsedda att enbart användas på en större skala på grund av begränsningar i data- och modellunderlaget. Havs- och vattenmyndigheten har begärt en utredning av hur underlag och beräkningar till HELCOM PLC6 kan förbättras i kvali-tet och skala för att även uppfylla behov av underlag till vattenmyndigheternas rapporte-ring enligt Vattenförvaltningsförordningen. För att bättre kunna använda PLC-data på lokal skala har Vattenmyndigheten för Norra Östersjön tidigare uttryckt önskemål om att dela läckageregion 6 (SCBs produktionsområde 6, PO6) i två regioner för att bättre mot-svara de produktionsskillnader som finns inom jordbruket i regionen.En analys av effekten av att dela region 6, Mälar- och Hjälmarbygden, i två delregioner har gjorts. En region, region 61, utgjordes av området runt Mälaren och Hjälmaren och region 62 var den övriga delen av region 6. Region 61 hade högre gödslings- och skörde-nivå, lägre avrinning, mindre andel vall och större andel clay än region 62. I arbetet har beräkningsmetoden inklusive kriterier och antaganden som beskrevs i PLC5-beräkningen använts (PLC5-metoden). Påverkan av olika gödslings- och skördenivåer, avrinning, grödosammansättning och jordartsammansättning har beräknats. I den regionala skalan var fosforutlakningen högre i region 61 än i region 62. Det var orsakat av större andel grödor och jordarter med hög utlakning jämfört med region 62. På koefficientnivån ob-serverades högre förluster av fosfor i region 61. Detta återspeglar förmodligen inte påver-kan av olika åtgärder i regionerna utan beror framförallt på avrinningsskillnader som ICECREAM-modellen visade hög känslighet för. Utlakningen av kväve (kg N/ha) i reg-ion 62 var högre än i region 61. Det berodde på högre andel jordarter med hög utlakning och högre avrinning än i region 62, trots att grödosammansättningen tydde på högre ut-lakning i region 61. Även koefficienterna var högre i region 62 än i 61. Gödslingsnivån var högre i region 61 men även skördenivån var högre och det gjorde att det var mindre kväve kvar i profilen som riskerade att utlakas.Osäkerheten i den beräknade vattenföringen som användes till PLC5 undersöktes för ett antal slumpmässigt utvalda avrinningsområden och visade sig vara större för mindre avrinningsområden jämfört med stora. Osäkerheten i kvävebruttobelastningen från den tidigare Monte Carlo-analysen visade också på större spridning i mindre områden jämfört med stora, ett liknande mönster – men mindre tydligt – kunde också ses för nettobelast-ningen. Erfarenheter från tidigare lokala studier visar att när PLC-data kompletteras och förbättras med lokala data blir överenstämmelsen mellan beräknade och uppmätta halter av kväve och fosfor oftast bättre jämfört med en modelluppsättning enbart baserad på 9PLC-data. Det går dock inte att generellt säga vilka data som är viktigast att komplettera med då påverkan från de olika typerna av källor varierar stort lokalt.TBV-belastningsresultaten har jämförts med observationsdata för 39 flodmynningar, men några jämförelser med observationsdata för små avrinningsområden av liknande skala som vattenförekomsterna har hittills inte gjorts. Det är därför prioriterat att i samband med PLC6 kvantifiera storleken på avvikelserna mot observationsdata för olika rumsliga skalor och därmed kunna bedöma och klassificera tillförlitligheten i resultaten, samt ge råd om hur dessa bör användas. Analysen av de vattenförings- och vattenkemidata som finns tillgängliga för modellkalibrering och utvärdering visade att få av de tillgängliga vattenföringsstationerna har små tillrinningsområden, medan det finns data över kväve och fosforhalter från fler små områden. Vattenföringsstationerna är väl fördelade över landet, medan tillgängligheten till kväve- och fosforhaltdata varierar mer mellan olika regioner. Det är därför viktigt att, om möjligt, samla in data från mindre avrinningsområ-den för resultatutvärderingen under PLC6.Fler rekommendationer för resultatutvärdering och tillförlitlighetsbedömning av PLC6- resultaten diskuteras i denna rapport. En lista över prioriterade områden för förbättring av indata till PLC6-beräkningarna ges i slutet av rapporten tillsammans med en diskussion om framtida behov av datainsamling och nationellt datavärdskap. Källor och indata som inte har någon större betydelse på den nationella skalan kan ha stor lokal inverkan, vilket gör att prioriteringen rör i stort sett alla typer av källor som bidrar till antropogen kväve-och fosforbelastning.
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| 31. |
- Westerberg, Karin, et al.
(författare)
-
Model-Based Process Challenge of an Industrial Ion-Exchange Chromatography Step
- 2012
-
Ingår i: Chemical Engineering & Technology. - : Wiley. - 1521-4125 .- 0930-7516. ; 35:1, s. 183-190
-
Tidskriftsartikel (refereegranskat)abstract
- The separation of one weakly and one strongly binding impurity from a therapeutic protein by ion-exchange chromatography was studied with a mechanistic model. The effect of disturbances in eight potentially critical process parameters on two critical quality attributes was evaluated. It was found that the outgoing concentration of the weakly binding impurity was only affected by the ingoing concentration of this impurity, while the target product purity was affected by the amounts of buffer and acid used to prepare the elution buffers and the protein concentration and purity of the feed. Full factor analysis of these parameters showed that there were interaction effects between the parameters due to the pH dependence of the chromatographic separation. Sampling-based robustness analysis estimated the probability of batch failure to be above 1?%. The model improved the analysis as it was possible to study the effects of more process parameters and their interactions than would have been possible in an experimental study.
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| 32. |
- Westerberg, Karin, et al.
(författare)
-
Model-based risk analysis of coupled process steps.
- 2013
-
Ingår i: Biotechnology and Bioengineering. - : Wiley. - 1097-0290 .- 0006-3592. ; 110:9, s. 2462-2470
-
Tidskriftsartikel (refereegranskat)abstract
- A section of a biopharmaceutical manufacturing process involving the enzymatic coupling of a polymer to a therapeutic protein was characterized with regards to the process parameter sensitivity and design space. To minimize the formation of unwanted by-products in the enzymatic reaction, the substrate was added in small amounts and unreacted protein was separated using size-exclusion chromatography (SEC) and recycled to the reactor. The quality of the final recovered product was thus a result of the conditions in both the reactor and the SEC, and a design space had to be established for both processes together. This was achieved by developing mechanistic models of the reaction and SEC steps, establishing the causal links between process conditions and product quality. Model analysis was used to complement the qualitative risk assessment, and design space and critical process parameters were identified. The simulation results gave an experimental plan focusing on the "worst-case regions" in terms of product quality and yield. In this way, the experiments could be used to verify both the suggested process and the model results. This work demonstrates the necessary steps of model-assisted process analysis, from model development through experimental verification. Biotechnol. Bioeng. © 2013 Wiley Periodicals, Inc.
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| 33. |
- Westerberg, Karin
(författare)
-
Modeling for Quality and Safety in Biopharmaceutical Production Processes
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- To design efficient and safe biopharmaceutical production processes, understanding the process and how it is affected by changes in the process conditions is essential. Experimental data form the basis of this understanding which can be enhanced by modeling and simulations of the physical and chemical processes known to control the process. This thesis describes modeling of preparative chromatography and how these models can be applied for the design and characterization of separation steps in biopharmaceutical processing. The process’ robustness to disturbances is studied by simulation of variations in the operating conditions, such as concentrations of target protein, impurities and modifying agents. The sensitivity to the process parameters and the overall risk of producing a product of low quality are determined. These simulation studies are used to find the process parameter variations most relevant to study experimentally. The model-based approach is demonstrated for two industrial case studies. Process simulations are also used to design and analyze control strategies for the preparative chromatography steps. Specifically, an algorithm is designed which selects the optimal cut points used to pool the product in the outlet flow in each batch. Flexible processes which can adapt to disturbances in the process inputs are shown to give higher yield and productivity and less variations in the output.
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| 34. |
- Westerberg, Karin, et al.
(författare)
-
Pooling control in variable preparative chromatography processes.
- 2010
-
Ingår i: Bioprocess and Biosystems Engineering. - : Springer Science and Business Media LLC. - 1615-7605 .- 1615-7591. ; 33, s. 375-382
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Tidskriftsartikel (refereegranskat)abstract
- Preparative chromatographic columns that run at high loads are highly sensitive to batch-to-batch disturbances of the process parameters, placing high demands on the strategy used for pooling of the product fractions. A new approach to pooling control is presented in a proof-of-concept study. A model-based sensitivity analysis was performed identifying the critical process parameters to product purity and optimal cut points. From this, the robust fixed cut points were found and pooling control strategies for variations in the critical parameters were designed. Direct measurements and indirect measurements based on the UV detector signal were used as control signals. The method is demonstrated for two case studies of preparative protein chromatography: hydrophobic interaction and reversed phase chromatography. The yield improved from 88.18 to 92.88% when changing from fixed to variable pooling in hydrophobic interaction chromatography, and from 35.15 to 76.27% in the highly sensitive reversed phase chromatography.
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| 35. |
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| 36. |
- Westerberg, Karin, et al.
(författare)
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Supporting Design and Control of a Reversed-Phase Chromatography Step by Mechanistic Modeling
- 2012
-
Ingår i: Chemical Engineering & Technology. - : Wiley. - 1521-4125 .- 0930-7516. ; 35:1, s. 169-175
-
Tidskriftsartikel (refereegranskat)abstract
- There is a need to design and understand control strategies for biopharmaceutical processes. The control strategy will influence the design space and process performance and should be chosen together with the operating point and design space. Mechanistic modeling is used to design and evaluate control strategies for product pooling in preparative chromatography. A kinetic dispersive model was calibrated to reversed-phase chromatography experiments. Uncorrelated process disturbances were introduced to optimized operating points, and the effects of disturbances were evaluated and reduced by control strategies. Pooling control was implemented at a fixed UV absorbance or as a function of retention volume and UV peak height. The higher flexibility of the second control strategy decreased the loss of yield and productivity caused by the disturbances.
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| 37. |
- Westerberg, Karin, et al.
(författare)
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Utveckling av samarbetsförmåga
- 2009
-
Ingår i: Proceedings 2:a Utvecklingskonferensen för Sveriges ingenjörsutbildningar.
-
Konferensbidrag (refereegranskat)
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| 38. |
- Westerberg, Lars-Ove, et al.
(författare)
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The development of the ancient irrigation system at Engaruka, northern Tanzania : Physical and societal factors
- 2010
-
Ingår i: Geographical Journal. - : Wiley. - 0016-7398 .- 1475-4959. ; 176:4, s. 304-318
-
Tidskriftsartikel (refereegranskat)abstract
- Climate data from Empakaai Crater in northern Tanzania, covering the last 1200 years, are related to the establishment, development and decline of the ancient irrigation system at Engaruka. New dates for the system are linked to reconstructed climatic variations and historical data on long-distance and regional trade and migration patterns. A shift from a comparatively humid climate to drier conditions in the 1400s prompted the establishment of irrigated agriculture at Engaruka, and a flourishing long-distance trade increased its value as a water and food source for passing caravans. Once established, the land-use system at Engaruka was sufficiently resilient to survive and even intensify during much drier climate from c. 1500 to 1670 CE (Common Era) and during the decline of caravan trade between c. 1550 and 1750. The ancient land-use system probably reached its maximum extension during the humid conditions between 1670 and 1740, and was deserted in the early to mid 1800s, presumably as a result of the added effects of climate deterioration, the Maasai expansion, and change of livelihood strategies as agriculturalists became pastoralists. Towards the end of the 1800s irrigated agriculture was again established at Engaruka, in part driven by the transfer from pastoral to agricultural livelihoods caused by the Rinderpest.
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| 39. |
- Öberg, Helena, 1974-, et al.
(författare)
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A diatom record of recent environmental change in Lake Duluti, northern Tanzania
- 2012
-
Ingår i: Journal of Paleolimnology. - : Springer Science and Business Media LLC. - 0921-2728 .- 1573-0417. ; 48:2, s. 401-416
-
Tidskriftsartikel (refereegranskat)abstract
- Lake Duluti is a small, topographically closed crater lake located on the flanks of Mt Meru, northern Tanzania. Analyses of diatoms in three short sediment cores and four modern samples from Lake Duluti were used to infer past environmental changes. 210Pb and 137Cs activity profiles combined with AMS 14C dates provide the chronological framework. Weak agreement between the 210Pb and 14C records, together with dating uncertainty, precludes construction of precise age models. The modern diatom flora, from plankton and three periphytic habitats, is dominated by Aulacoseira ambigua (Grunow) Simonsen, Gomphonema parvulum (Kützing) Grunow and Nitzschia amphibia Grunow. All three cores display similar stratigraphic succession, but the relative ratio of habitats represented by the diatoms varies substantially between cores. Diatoms indicate that the oldest part of the record is characterized by relatively low lake level and swampy vegetation. In the late nineteenth or early twentieth century there was a rapid lake level rise and the swamp turned into an open-water lake. High lake levels have prevailed since that time.
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| 40. |
- Öberg, Helena, 1974-
(författare)
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Diatoms in Lake Duluti : Tracking Environmental Variability in Northern Tanzania during the Past 1000 Years
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The tropics are the regions which are least understood climatically and new data on past climate variability is necessary for reliable future modeling of climate change. This thesis contributes with new paleoenvironmental information from a small crater lake in northern Tanzania and provides an additional link between the integrated history of climate, environment and socioeconomic variability in tropical Africa. Pollen and diatom records from three short sediment cores and one piston core have been used to infer variations in past climate and environmental conditions. The chronological framework has been established by 210Pb and 137Cs activity profiles combined with AMS 14C dates on bulk sediment and Bayesian statistics have been used to construct the age-models. Together, the four cores cover approximately the last 1000 years. Modern limnological conditions (temperature, dissolved oxygen, pH and conductivity) and diatom assemblages from plankton, vegetation, stone scrape and near shore sediments have been surveyed to facilitate the paleoenvironmental interpretation. A detailed morphological analysis of Discostella species in Lake Duluti is presented. Frustule morphology of Discostella species have been examined using light microscope (LM) and scanning electron microscope (SEM) and led to the identification of a new variety; Discostella woltereckii v. minor Öberg, Risberg & Stabell. The multi-proxy record from the piston core infers dry conditions c. AD 1040–1470. Between c. AD 1470 and 1510 there are moist conditions with a lake high-stand centered on c. AD 1490. The period c. AD 1510–1640 is dry and between c. AD 1640 and 1790 there are indications of a continuously increase in moisture and higher lake levels, with a brief reversals in the 1660s. The results from the short cores indicate dry conditions from the late 19th century followed by a rapid rise in lake level sometime in the early 20th century. The observed trends show a good correlation with other paleoenvironmental data from East Africa. The results support the general hypothesis of regionally-wide dry conditions in the beginning of the last millennium and an inverse humidity pattern between western equatorial and eastern equatorial sites during the last centuries.
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| 41. |
- Öberg, Helena, et al.
(författare)
-
Environmental variability in northern Tanzania from AD 1000 to 1800, as inferred from diatoms and pollen in Lake Duluti
- 2013
-
Ingår i: Palaeogeography, Palaeoclimatology, Palaeoecology. - : Elsevier BV. - 0031-0182 .- 1872-616X. ; 374, s. 230-241
-
Tidskriftsartikel (refereegranskat)abstract
- Fossil pollen and diatoms have been analyzed in a sediment sequence from a topographically closed crater lake in northern Tanzania (Lake Duluti), with the aim to reconstruct past changes in lake level and vegetation dynamics. The results provide a new paleoenvironmental record from equatorial Africa covering the period c. AD 1000 to AD 1800. Overall, the pollen and diatom records generate comparable stories of dry and wet periods. Dry conditions are inferred at c. AD 1040-1470, c. AD 1510-1640 and C. AD 1650-1670 with the lowest lake levels at c. AD 1260-1290 and AD 1600-1640. Wetter conditions occurred c. AD 1640-1650 and c. AD 1670-1790. The chronology is based on combined analyses of Pb-210 activity and AMS C-14 on bulk sediment, and a Bayesian model was applied to establish the age-depth relationship. The hydroclimatic record from Lake Duluti shows good correlation with several East African lakes in a centennial time perspective, although comparison of high frequency variability in the region is hampered by dating uncertainties.
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| 42. |
- Öberg, Helena, 1974-, et al.
(författare)
-
Environmental variability in northern Tanzania from c. AD 1000 to 1800, as inferred from diatoms and pollen in Lake Duluti
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Fossil pollen and diatoms have been analysed in a sediment sequence from a topographically closed crater lake in northern Tanzania(Lake Duluti), with the aim to reconstruct past changes in lake level and vegetation dynamics. The results contribute with a new paleoenvironmental record from equatorial Africacovering the period c. AD 1000 to AD 1800. Overall, the pollen and diatom records generate comparative stories of dry and wet periods. Dry conditions are inferred at c. AD 1040–1470, c. AD 1510–1640 and c. AD 1650–1670 with the lowest lake levels at c. AD 1260–1290 and AD 1600–1640. Wetter conditions occurred c. AD 1640–1650 and c. AD 1670–1790. The chronology is based on combined analyses of 210Pb activity and AMS 14C on bulk sediment, and a Bayesian model was applied to establish the age-depth relationship. The hydroclimatic record fromLakeDuluti shows good correlation with several East African lakes although precise comparison is hampered by dating uncertainties.
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