| 1. |
- Callaghan, Terry, et al.
(författare)
-
Multi-Decadal Changes in Tundra Environments and Ecosystems : Synthesis of the International Polar Year-Back to the Future Project (IPY-BTF)
- 2011
-
Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 40:6, s. 705-716
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding the responses of tundra systemsto global change has global implications. Most tundraregions lack sustained environmental monitoring and oneof the only ways to document multi-decadal change is toresample historic research sites. The International PolarYear (IPY) provided a unique opportunity for such researchthrough the Back to the Future (BTF) project (IPY project#512). This article synthesizes the results from 13 paperswithin this Ambio Special Issue. Abiotic changes includeglacial recession in the Altai Mountains, Russia; increasedsnow depth and hardness, permafrost warming, andincreased growing season length in sub-arctic Sweden;drying of ponds in Greenland; increased nutrient availabilityin Alaskan tundra ponds, and warming at mostlocations studied. Biotic changes ranged from relativelyminor plant community change at two sites in Greenland tomoderate change in the Yukon, and to dramatic increasesin shrub and tree density on Herschel Island, and in subarcticSweden. The population of geese tripled at one sitein northeast Greenland where biomass in non-grazed plotsdoubled. A model parameterized using results from a BTFstudy forecasts substantial declines in all snowbeds andincreases in shrub tundra on Niwot Ridge, Colorado overthe next century. In general, results support and provideimproved capacities for validating experimental manipulation,remote sensing, and modeling studies.
|
|
| 2. |
- Akselsson, Cecilia, et al.
(författare)
-
Weathering rates in Swedish forest soils
- 2019
-
Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 16:22, s. 4429-4450
-
Forskningsöversikt (refereegranskat)abstract
- Soil and water acidification was internationally recognised as a severe environmental problem in the late 1960s. The interest in establishing “critical loads” led to a peak in weathering research in the 1980s and 1990s, since base cation weathering is the long-term counterbalance to acidification pressure. Assessments of weathering rates and associated uncertainties have recently become an area of renewed research interest, this time due to demand for forest residues to provide renewable bioenergy. Increased demand for forest fuels increases the risk of depleting the soils of base cations produced in situ by weathering. This is the background to the research programme Quantifying Weathering Rates for Sustainable Forestry (QWARTS), which ran from 2012 to 2019. The programme involved research groups working at different scales, from laboratory experiments to modelling. The aims of this study were to (1) investigate the variation in published weathering rates of base cations from different approaches in Sweden, with consideration of the key uncertainties for each method; (2) assess the robustness of the results in relation to sustainable forestry; and (3) discuss the results in relation to new insights from the QWARTS programme and propose ways to further reduce uncertainties. In the study we found that the variation in estimated weathering rates at single-site level was large, but still most sites could be placed reliably in broader classes of weathering rates. At the regional level, the results from the different approaches were in general agreement. Comparisons with base cation losses after stem-only and whole-tree harvesting showed sites where whole-tree harvesting was clearly not sustainable and other sites where variation in weathering rates from different approaches obscured the overall balance. Clear imbalances appeared mainly after whole-tree harvesting in spruce forests in southern and central Sweden. Based on the research findings in the QWARTS programme, it was concluded that the PROFILE/ForSAFE family of models provides the most important fundamental understanding of the contribution of weathering to long-term availability of base cations to support forest growth. However, these approaches should be continually assessed against other approaches. Uncertainties in the model approaches can be further reduced, mainly by finding ways to reduce uncertainties in input data on soil texture and associated hydrological parameters but also by developing the models, e.g. to better represent biological feedbacks under the influence of climate change.
|
|
| 3. |
- Berg, Håkan, et al.
(författare)
-
Characterization of antibodies for quantitative determination of spiggin protein levels in male and female three-spined stickleback (Gasterosteus aculeatus)
- 2009
-
Ingår i: Reproductive Biology and Endocrinology. - : BioMed Central (BMC). - 1477-7827. ; 7:1
-
Tidskriftsartikel (refereegranskat)abstract
- Spiggin is an adhesive glycoprotein produced in the kidney of sticklebacks during the breeding season and is subsequently secreted into the urinary bladder from where it is employed for nest building. Since the production of the protein has been shown to be under androgenic control, spiggin has been suggested to be a useful biomarker for androgenic substances in the environment. In this study, two polyclonal spiggin antibodies based on synthetic peptides and one polyclonal antibody directed against native spiggin have been characterized. The antibodies ability to identify spiggin was investigated by quantitative immunoassay. For both peptide antibodies the quantification range was determined to be between 1 and 80 ng spiggin and determination of renal spiggin levels from immature and mature males displayed a 15-fold increase in total spiggin content of the kidney resulting in a 6-fold increase in male kidney weight due to hypertrophy. The kidney somatic index (KSI) was found to correlate well with the total renal spiggin content and therefore it appears that KSI in sticklebacks could be used as an initial method to identify substances displaying androgenic effects. Furthermore, western blot analysis revealed that the polyclonal antibodies recognize different spiggin isoforms and that spiggin can be detected in the urinary bladder and kidney of both males and female sticklebacks. In order to develop a quantitative detection method for native spiggin it is necessary to produce a standard that can be used in a bioassay. Due to the adhesive and polymerization characteristics of spiggin the protein is difficult to use as a standard in bioassays. So far spiggin has been shown to exist in at least 14 isoforms, all of which contain polymerization domains. To overcome the solubility problem we have produced recombinant spiggin gamma, with only one polymerization domain, that can be expressed in E. coli. Western blot analysis demonstrated that the polyclonal antibodies were able to detect recombinant spiggin gamma protein in bacterial cell lysate, suggesting that it may be developed into a useful source of standard spiggin to be used for quantitative determination of androgen induced spiggin production in sticklebacks.
|
|
| 4. |
- Hell, Benjamin, 1977-
(författare)
-
Towards the compilation of a new Digital Bathymetric Model of the North Atlantic Ocean
- 2009
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Topography on land and bathymetry, its underwater depth equivalent, belong to the most fundamental attributes of the solid earth's surface. Over two thirds of the earth is covered by water, with about 90% of this area lying more than 1000m below the sea surface. In contrast to the land area, most of the deep sea remains largely unexplored and to date the topography of the Moon or Mars is much better known than the bathymetry of large parts of our own planet.Deep sea ocean mapping can directly be carried out with ship-bound echo sounders or indirectly through a remote sensing method known as satellite altimetry. Modern echo sounding technology allows for high resolution mapping with unsurpassed accuracy. Due to the vastness of the oceans, however, even after decades of mapping activity, the oceans are far from completely surveyed, and the echo soundings accumulated over the time with different, meanwhile evolving technologies are of highly varying quality. Satellite altimetry, on the contrary, provides virtually complete coverage of the entire globe, although the achieved resolution and accuracy is limited. For the compilation of consistent, ocean spanning Digital Bathymetric Models (DBMs) from raw depth measurements, an appropriate data basis is therefore a heterogeneous mixture of historical and contemporary echo soundings, complemented by satellite altimetry as needed. The North Atlantic is by far the best mapped of all oceans and as such it provides an ideal area to study scientific problems related to ocean mapping and DBM compilation. The heterogeneity and size of the global bathymetric data basis require powerful solutions to handle and process both data and metadata effectively. In this work, a spatial relational database in combination with a geographical information system (GIS) form a flexible tool kit for a DBM compilation, and a data model for the storage and retrieval of both data and metadata is developed. In a case study I show the potential of the available sounding data in the North Atlantic to derive a DBM with significant improvements over the models commonly used today. Many geoscientific applications require that data sets are sampled on a regularly spaced grid, notwithstanding the fact that data acquisition often provides measurements at irregular positions and with incomplete coverage.Several methods exist for interpolating and gridding raw data to obtain gapless grids. In ocean mapping, minimum curvature bicubic splines in tension are a commonly used approach. This work presents a refined technique, multiple resolution splines in tension. The method takes the local data density into consideration during the gridding process, in order to reduce gridding artifacts mainly caused by very inhomogeneous data coverage. It is shown that multiple resolution splines in tension allow for a high maximum grid resolution, without introducing artifacts that appear with regular splines in tension interpolation at the same resolution.
|
|
| 5. |
- Marklund, Liselott, et al.
(författare)
-
Utveckling av metodik för flygbildstolkning inom NILS landskapsrutor (5x5 km)
- 2007
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Miljöövervakningsprogrammet Nationell Inventering av Landskapet i Sverige (NILS) bygger på en kombination av fältinventering och flygbildstolkning och ger ett dataunderlag för att skatta tillstånd och förändringar i det svenska landskapets alla naturtyper. För att utföra landskapsanalyser krävs data från ett större område än den centrala kilometerruta (1 km 2) som utgör basen inom NILS. Den omgivande landskapsrutan (25 km2) är där ett viktigt komplement för att kunna beskriva den rumsliga fördelningen av olika typer av landskapselement, och landskapets fragmenteringsgrad, med mera.Projektet har syftat till att ta fram ett beslutsunderlag som ska ligga till grund för beslut om hur flygbildstolkningen av landskapsrutan ska utföras.Utgångspunkten i projektet har varit att ta hänsyn till så många användarbehov som möjligt vid förslaget på tolkningsmetodik. Undersökningen av användarbehov har till stor del baserats på den informationsanalys (Esseen et al . 2004) som legat till grund för designen av NILS. Genomgången visar att de största användarbehoven är att kunna följa landskapets sammansättning och struktur. För att detta ska vara möjligt krävs uppgifter om storlek, form och rumslig fördelning av en mängd marktäcketyper och markanvändning. Användarnas behov av detaljeringsgrad varierar och inom urban miljö och inom odlingslandskapet är kraven på detaljeringsnivå är högre jämfört med skogsmark och våtmarker, där en högre generaliseringsgrad kan tolereras.Metodtester och en genomgång av nya tekniker och metoder för datafångst och tolkning har genomförts med utgångspunkt från de användarbehov som påtalats i informationsanalysen (Esseen et al . 2004). Ett förslag på möjlig klassificering har framarbetats för att visa på den detaljeringsgrad som krävs vid tolkningen för att skapa vissa typer av markslagsklasser.Förslaget baseras i första hand på användarbehoven varför vissa avvikelser från ett vanligt hierarkiskt klassificeringssystem förekommer.De metoder som testat har varit manuell flygbildstolkning med stöd av befintliga GIS-data och tolkning med stöd av segmenteringsprocesser. Metodtesterna har utmynnat i förslag på tolkningskoncept för landskapsrutan indelat på 3 scenarier.I scenario 1 redovisas en manuell lösning som bygger på en kombination av manuell flygbildstolkning och nyttjande av befintliga eller kommande GIS-data.I scenario 2 redovisas en kombination av manuella och semiautomatiska metoder som bygger på manuell flygbildstolkning, nyttjade av befintliga GIS-data som kNN-Sverige och segmentering, där segmenteringen utnyttjas för polygonavgränsning, framförallt i skog.I scenario 3 redovisas ett framtidsscenario där det är möjligt att kombinera data från flygbilder och laserskanning med segmenteringsprocesser, semiautomatisk klassning av segment och manuell flygbildstolkning kontroll och tolkning.Slutsatsen är att scenario 1 är den mest kostsamma lösningen och scenarion 3 är inte möjligt att genomföra inom den närmaste framtiden varför scenario 2 bedöms vara det alternativ som har högst potential att vara kostnadseffektivt. Slutsatsen blir att förslaget i scenario 2 behöver avgränsas ytterligare och att det krävs utförliga metodtester för att kunna bedöma den totala kostnadsbilden för förslaget.
|
|
| 6. |
- Olsson, Eva-Karin, 1973-
(författare)
-
Media Crisis Decision Making : A Case Study of SR (Swedish Radio), SVT (Swedish Television) and TV4
- 2008
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The study takes as its starting point that news organizations’ actions during crises vary more than one can expect based on previous research on news work. Accordingly, the dissertation aims to move beyond the notion of news organizations as homogenous and attempts to open the ‘black box’ of news organizations’ decision making. The study is based on interviews with members of three Swedish broadcasting organizations: the Swedish Public Television (SVT), the Swedish Public Radio (SR), and TV4. The interviews focused on how the three organizations dealt with the news coverage of the September 11th 2001 terrorist attacks in the USA. The four articles included in this dissertation challenge from different perspectives the previous assumptions presented in the field of media and journalism. First, as a response to the variety of definitions of non-routine news events applied in previous research, Article I sets out to propose a definition of crisis news events from a news organizational perspective. Accordingly, the article proposes to understand crisis news as surprise events that challenge key organizational values and that demand a swift response. Second, in questioning the notion of news organizations as homogenous, Article II examines the actions taken by the three Swedish broadcasting organizations in response to 9/11. This article argues, based on a neo-institutional perspective, that news organizations’ decision making can be explained by differences in organizational ‘rule-regimes’. Third, Article III challenges the assumption that newsroom actions are homogeneous by examining two newsroom responses to 9/11, in particular their everyday organizational structures and previous experiences. The last Article (IV) applies a slightly different perspective in arguing that during crises media managers’ decisions are not only influenced by the audiences’ informational needs but also by the ritual role news organizations play in times of crises.
|
|
| 7. |
- Scaini, Anna, et al.
(författare)
-
Pathways from research to sustainable development: Insights from ten research projects in sustainability and resilience
- 2024
-
Ingår i: AMBIO. - : Springer Nature. - 0044-7447 .- 1654-7209. ; 53
-
Tidskriftsartikel (refereegranskat)abstract
- Drawing on collective experience from ten collaborative research projects focused on the Global South, we identify three major challenges that impede the translation of research on sustainability and resilience into better-informed choices by individuals and policy-makers that in turn can support transformation to a sustainable future. The three challenges comprise: (i) converting knowledge produced during research projects into successful knowledge application; (ii) scaling up knowledge in time when research projects are short-term and potential impacts are long-term; and (iii) scaling up knowledge across space, from local research sites to larger-scale or even global impact. Some potential pathways for funding agencies to overcome these challenges include providing targeted prolonged funding for dissemination and outreach, and facilitating collaboration and coordination across different sites, research teams, and partner organizations. By systematically documenting these challenges, we hope to pave the way for further innovations in the research cycle.
|
|
| 8. |
- Sundström, Johan, Professor, 1971-, et al.
(författare)
-
Rationale for a Swedish cohort consortium
- 2019
-
Ingår i: Upsala Journal of Medical Sciences. - : Taylor & Francis Group. - 0300-9734 .- 2000-1967. ; 124:1, s. 21-28
-
Tidskriftsartikel (refereegranskat)abstract
- We herein outline the rationale for a Swedish cohort consortium, aiming to facilitate greater use of Swedish cohorts for world-class research. Coordination of all Swedish prospective population-based cohorts in a common infrastructure would enable more precise research findings and facilitate research on rare exposures and outcomes, leading to better utilization of study participants' data, better return of funders' investments, and higher benefit to patients and populations. We motivate the proposed infrastructure partly by lessons learned from a pilot study encompassing data from 21 cohorts. We envisage a standing Swedish cohort consortium that would drive development of epidemiological research methods and strengthen the Swedish as well as international epidemiological competence, community, and competitiveness.
|
|
