| 1. |
- Kehoe, Laura, et al.
(författare)
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Make EU trade with Brazil sustainable
- 2019
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6438, s. 341-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 7. |
- Olsson, Tobias, et al.
(författare)
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Introduction
- 2013
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Ingår i: Producing the Internet: Critical Perspectives of Social Media. - 9789186523596 ; , s. 7-21
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Bokkapitel (refereegranskat)
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| 8. |
- Olsson, Tobias, et al.
(författare)
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Remaining divides : Access to and use of ICTs among elderly citizens
- 2016
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Ingår i: Politics, Civil Society and Participation : Media and Communications in Transforming Environment - Media and Communications in Transforming Environment. - Bremen : edition lumière. - 1736-4752 .- 1736-3918. - 9783943245547 ; 11, s. 273-286
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Bokkapitel (refereegranskat)abstract
- The ambition to make all kinds of societal services, public as well as commercial ones, more effective and accessible via online applications is reoccurring all over the western world. To a large extent, such ambitions hold the promise to make citizens’ everyday lives easier, but they are, however, also problematic in that they presuppose a number of important prerequisites. They presuppose widespread access to ICT-applications of a standard that is fast and solid enough to manage to make users actually make use of these services. They further presuppose that all citizens and consumers, who are the inscribed users of these applications, have enough competences and skills to make use of them. Hence, there is an obvious risk that people who do not have access are being left behind in the transformations of these services from analogue to digital. In this chapter we attend to these risks by paying attention to contemporary patterns of access to, and use of, digital applications. The chapter is inspired by domestication theory and looks into and analyses different patterns of ICT access and use among Swedish senior citizens, with the following questions in mind: What ICT-devices do various groups of senior citizens have access to? To what extent do they make everyday use of them? For what purposes do they use these devices? The empirical material has been derived from a pilot survey which was conducted from August to September 2015.
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| 9. |
- Olsson, Tobias, et al.
(författare)
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Sociala medier: en introduktion
- 2017
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Ingår i: Sociala medier - vetenskapliga perspektiv. - 9789140694805 ; , s. 9-20
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 10. |
- Azevedo, Flavio, et al.
(författare)
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Social and moral psychology of COVID-19 across 69 countries
- 2023
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Ingår i: Scientific Data. - : NATURE PORTFOLIO. - 2052-4463. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- The COVID-19 pandemic has affected all domains of human life, including the economic and social fabric of societies. One of the central strategies for managing public health throughout the pandemic has been through persuasive messaging and collective behaviour change. To help scholars better understand the social and moral psychology behind public health behaviour, we present a dataset comprising of 51,404 individuals from 69 countries. This dataset was collected for the International Collaboration on Social & Moral Psychology of COVID-19 project (ICSMP COVID-19). This social science survey invited participants around the world to complete a series of moral and psychological measures and public health attitudes about COVID-19 during an early phase of the COVID-19 pandemic (between April and June 2020). The survey included seven broad categories of questions: COVID-19 beliefs and compliance behaviours; identity and social attitudes; ideology; health and well-being; moral beliefs and motivation; personality traits; and demographic variables. We report both raw and cleaned data, along with all survey materials, data visualisations, and psychometric evaluations of key variables.
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| 11. |
- 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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| 12. |
- Fager, Cecilia, 1990, et al.
(författare)
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Correlating 3D porous structure in polymer films with mass transport properties using FIB-SEM tomography
- 2021
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Ingår i: Chemical Engineering Science: X. - : Elsevier BV. - 2590-1400. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Porous polymer coatings are used to control drug release from pharmaceutical products. The coating covers a drug core and depending on the porous structure, different drug release rates are obtained. This work presents mass transport simulations performed on porous ethyl cellulose films with different porosities. The simulations were performed on high spatial resolution 3D data obtained using a focused ion beam scanning electron microscope. The effective diffusion coefficient of water was determined using a diffusion chamber. Lattice Boltzmann simulations were used to simulate water diffusion in the 3D data. The simulated coefficient was in good agreement with the measured coefficient. From the results it was concluded that the tortuosity and constrictivity of the porous network increase with decreasing amount of added hydroxypropyl cellulose, resulting in a sharp decrease in effective diffusion. This work shows that high spatial resolution 3D data is necessary, and that 2D data is insufficient, in order to predict diffusion through the porous structure with high accuracy.
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| 13. |
- Fagrell, Tobias G., et al.
(författare)
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Bacterial invasion of dentinal tubules beneath apparently intact but hypomineralized enamel in molar teeth with molar incisor hypomineralization
- 2008
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Ingår i: International Journal of Paediatric Dentistry. - 0960-7439 .- 1365-263X. ; 18:5, s. 333-340
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The most common problems for a patient with molar incisor hypomineralization (MIH) are the collapse of enamel and cavitations, loss of fillings, and secondary caries, but most of all, severe hypersensitivity. OBJECTIVE: The aim of this paper was therefore to histologically study possible bacterial invasion of dentinal tubules beneath apparently intact, but hypomineralized enamel in permanent molars with MIH. MATERIAL AND METHODS: Five extracted permanent first molars diagnosed with MIH were fixated, demineralized, and sagittally serially sectioned in a bucco-lingual direction in a microtome with a thickness of 4-5 microm. Sections were stained with a modified Brown and Benn staining for bacteria, unstained sections were analysed in field emission SEM. RESULTS: Stained sections from the cuspal areas, below the hypomineralized enamel, the staining indicated the presence of bacteria in the dentinal tubules. The HTX staining showed that the pulp in sections without any findings was normal and free from bacteria or infiltrates from inflammatory cells. In sections where bacteria were found in the cuspal areas or deeper in the dentin, a zone of reparative dentin was found, and in sections from one tooth, the coronal pulp showed an inflammatory reaction with inflammatory cells. In sections adjacent to those without any bacterial staining, the SEM analyses revealed empty dentinal tubules without any odontoblast processes or signs of bacteria. When odontoblast processes were found, the dentinal tubules were filled with bacteria located on the surface of the odontoblast processes. In some areas, a large number of tubules were found with bacteria. No bacteria were found close to the pulp. The odontoblast processes appeared larger in areas where bacteria were found. CONCLUSIONS: The presence of bacteria in the dentinal tubules and inflammatory reactions in the pulp indicate that oral bacteria may penetrate through the hypomineralized enamel into the dentin, thus possibly contribute to hypersensitivity of teeth with MIH.
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| 14. |
- Fransson, Dan, 1980, et al.
(författare)
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Skeletal muscle and performance adaptations to high-intensity training in elite male soccer players : speed endurance runs versus small-sided game training
- 2018
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Ingår i: European Journal of Applied Physiology. - : Springer. - 1439-6319 .- 1439-6327. ; 118:1, s. 111-121
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Tidskriftsartikel (refereegranskat)abstract
- To examine the skeletal muscle and performance responses across two different exercise training modalities which are highly applied in soccer training. Using an RCT design, 39 well-trained male soccer players were randomized into either a speed endurance training (SET; n = 21) or a small-sided game group (SSG; n = 18). Over 4 weeks, thrice weekly, SET performed 6-10 x 30-s all-out runs with 3-min recovery, while SSG completed 2 x 7-9-min small-sided games with 2-min recovery. Muscle biopsies were obtained from m. vastus lateralis pre and post intervention and were subsequently analysed for metabolic enzyme activity and muscle protein expression. Moreover, the Yo-Yo Intermittent Recovery level 2 test (Yo-Yo IR2) was performed. Muscle CS maximal activity increased (P < 0.05) by 18% in SET only, demonstrating larger (P < 0.05) improvement than SSG, while HAD activity increased (P < 0.05) by 24% in both groups. Na+-K+ ATPase alpha(1) subunit protein expression increased (P < 0.05) in SET and SSG (19 and 37%, respectively), while MCT4 protein expression rose (P < 0.05) by 30 and 61% in SET and SSG, respectively. SOD2 protein expression increased (P < 0.05) by 28 and 37% in SET and SSG, respectively, while GLUT-4 protein expression increased (P < 0.05) by 40% in SSG only. Finally, SET displayed 39% greater improvement (P < 0.05) in Yo-Yo IR2 performance than SSG. Speed endurance training improved muscle oxidative capacity and exercise performance more pronouncedly than small-sided game training, but comparable responses were in muscle ion transporters and antioxidative capacity in well-trained male soccer players.
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| 15. |
- Idström, Alexander, et al.
(författare)
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Dissolution of cellulose in tetrabutylammonium acetate/dimethyl sulfoxide
- 2016
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Ingår i: The 7th Workshop on cellulose, regenerated cellulose and cellulose derivatives. ; , s. 15-18
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The dissolution of cellulose in tetrabutylammonium acetate (TBAAc)/dimethyl sulfoxide (DMSO) was studied combining experimental and simulation techniques. It was found that the dissolution limit at 40 °C corresponded to a molar ratio close to one acetate per cellulose anhydroglucose units. MD simulations suggested that the acetate ions bind to cellulose by dual hydrogen bonds. This effectively turns cellulose into a polyelectrolyte, attracting the bulky tetrabutylammonium (TBA+) counter ions, which prevent close contact between chains in the dissolved state. This hypothesis was tested by 1H- and 13C-NMR spectroscopy, which confirmed that acetate forms hydrogen bonds to cellulose, and by diffusion NMR spectroscopy, which demonstrated a strong dynamic correlation between bound acetate and tetrabutylammonium in near-quantitative agreement with simulation. The present results suggest that offering hydrogen bonding to the acetate ions is the main driving force for dissolving cellulose and that the TBA+ counter ions form a diffuse layer around the acetate-decorated cellulose chains.
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| 16. |
- Idström, Alexander, et al.
(författare)
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On the dissolution of cellulose in tetrabutylammonium acetate/dimethyl sulfoxide : a frustrated solvent
- 2017
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Ingår i: Cellulose. - : Springer Science and Business Media LLC. - 0969-0239 .- 1572-882X. ; 24:9, s. 3645-3657
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Tidskriftsartikel (refereegranskat)abstract
- We have found that the dissolution of cellulose in the binary mixed solvent tetrabutylammonium acetate/dimethyl sulfoxide follows a previously overlooked near-stoichiometric relationship such that one dissolved acetate ion is able to dissolve an amount of cellulose corresponding to about one glucose residue. The structure and dynamics of the resulting cellulose solutions were investigated using small-angle X-ray scattering (SAXS) and nuclear magnetic resonance techniques as well as molecular dynamics simulation. This yielded a detailed picture of the dissolution mechanism in which acetate ions form hydrogen bonds to cellulose and causes a diffuse solvation sheath of bulky tetrabutylammonium counterions to form. In turn, this leads to a steric repulsion that helps to keep the cellulose chains apart. Structural similarities to previously investigated cellulose solutions in aqueous tetrabutylammonium hydroxide were revealed by SAXS measurement. To what extent this corresponds to similarities in dissolution mechanism is discussed.
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| 21. |
- Van Bavel, Jay J., et al.
(författare)
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National identity predicts public health support during a global pandemic
- 2022
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Ingår i: Nature Communications. - : Nature Portfolio. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Understanding collective behaviour is an important aspect of managing the pandemic response. Here the authors show in a large global study that participants that reported identifying more strongly with their nation reported greater engagement in public health behaviours and support for public health policies in the context of the pandemic. Changing collective behaviour and supporting non-pharmaceutical interventions is an important component in mitigating virus transmission during a pandemic. In a large international collaboration (Study 1, N = 49,968 across 67 countries), we investigated self-reported factors associated with public health behaviours (e.g., spatial distancing and stricter hygiene) and endorsed public policy interventions (e.g., closing bars and restaurants) during the early stage of the COVID-19 pandemic (April-May 2020). Respondents who reported identifying more strongly with their nation consistently reported greater engagement in public health behaviours and support for public health policies. Results were similar for representative and non-representative national samples. Study 2 (N = 42 countries) conceptually replicated the central finding using aggregate indices of national identity (obtained using the World Values Survey) and a measure of actual behaviour change during the pandemic (obtained from Google mobility reports). Higher levels of national identification prior to the pandemic predicted lower mobility during the early stage of the pandemic (r = -0.40). We discuss the potential implications of links between national identity, leadership, and public health for managing COVID-19 and future pandemics.
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| 22. |
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| 25. |
- Abalo, Ernesto, et al.
(författare)
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Emerging Patterns of Inclusion and Exclusion in the Era of E-government : A Study of Users of ‘Swedish Public Employment Service’ on the Internet
- 2008
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Ingår i: Media and Global Divides. - Stockholm : Organizing Committee for the IAMCR Congress 2008. - 918835430X ; , s. 44-45
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Konferensbidrag (refereegranskat)abstract
- In the area of governmental information for and services to citizens digitalization has certainly become a buzzword. Framed within the discourses on e-government or e-governance – or different mixtures of the two – various analyses have tried to point out, or even anticipate possible consequences of the appropriation of digital technologies, mainly the internet, in governmental services.On the one hand, these analyses have pointed out a great deal of opportunities connected to the incorporation of the internet into governmental information and services. Policy makers have been quick to point to the increased accessibility as a great opportunity for the citizens; in Sweden this vision of accessibility has even been referred to as ‘24:7-governmental agencies’. Academics, among others, have also suggested that the digitalization of information and services opens up new possibilities for citizen control of governments.On the other hand, a number of problems have also been identified. For instance, the digitalization of public registers holding personal information has been interpreted as a threat to the citizens’ integrity: Will digitalization bring a new surveillance society? The most frequently debated problem, however, at least within research, has been the fear of digital divides. Will the internet create digital cleavages between different groups of citizens?So far, however, neither the hopeful nor the dystopian analyses have made enough efforts to critically evaluate their claims. Such evaluations can start from different points of departure, and in this paper the starting point is the citizens as users of governmental information and services through the internet: What patterns of inclusion and exclusion emerge as a governmental agency digitalizes its information and services by making them increasingly internet based?The paper presents statistical data from a survey of 762 unemployed citizens using the Swedish Public Employment Service, a governmental agency that has come to rely specifically heavy on internet based information and service. The initial analysis of data reveals interesting differences between social groups in terms of both perception and use of the internet – in general – and the resources offered by SPES in particular. For instance, the users’ various degrees of education is a strong, determining factor when it comes to use of internet SPES’ services.The paper starts from a conceptual elaboration of various notions of e-government and e-governance. Thereafter, the survey data is described and elaborated on before moving into a discussion of the wider significance of the findings: What does data suggest in terms of patterns of inclusion in and exclusion from a society in which governmental agencies, to an increasing extent, use the internet for their information and services?
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| 26. |
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| 27. |
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| 28. |
- 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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| 29. |
- Alkan Olsson, Johanna, et al.
(författare)
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Mapping the governance complex of land use policies for compensation
- 2019
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Ecological compensation is the latest member of a growing family of concepts aimed at reducing degradation of environmental quality. This and other concepts of the family – like ecosystem services, green infrastructure, and nature-based solutions – have been subject to a range of different interpretations and subsequent implementation practices. The result is a complex governance system with unclear boundaries and implications for the management efforts of environmental quality. In this paper, we seek to map and disentangle this complexity – with a particular focus on ecological compensation and related concepts (such as biodiversity offsetting and no net loss), which all have gained momentum in recent years and which share the notion that intrusion in nature should be compensated in one way or the other. In a first step, we seek to map similarities, differences and overlaps, between the concepts, by using a set of analytical categories including: the origin of the concept (scientific or policy context), the aim of its application, the type of decision-making process it generates, its relation to urban or rural contexts, and the extent to which it has been subjected to regulation. In a second step, and as a result of this mapping, we will advance knowledge about how governments, municipalities and business actors in different ways work with environmental quality, ecosystem services and biodiversity. First, we draw conclusions about the degree to which the concepts under scrutiny are mutually reinforcing or competing. Second, our analysis enables conclusions about why some concepts are preferred in certain institutional contexts and what institutional preconditions are needed for their use. Third, we discuss possible implications of this governance complexity for questions of effectiveness and legitimacy.
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| 30. |
- Almgren, Susanne, 1967-, et al.
(författare)
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Commenting, sharing and tweeting news : Measuring online news participation
- 2016
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Ingår i: Nordicom Review. - : De Gruyter Open. - 1403-1108 .- 2001-5119. ; 37:2, s. 67-81
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Tidskriftsartikel (refereegranskat)abstract
- Social plugins for sharing news through Facebook and Twitter have become increasingly salient features on news sites. Together with the user comment feature, social plugins are the most common way for users to contribute. The wide use of multiple features has opened new areas to comprehensively study users’ participatory practices. However, how do these opportunities to participate vary between the participatory spaces that news sites affiliated with local, national broadsheet and tabloid news constitute? How are these opportunities appropriated by users in terms of participatory practices such as commenting and sharing news through Facebook and Twitter? In addition, what differences are there between news sites in these respects? To answer these questions, a quantitative content analysis has been conducted on 3,444 articles from nine Swedish online newspapers. Local newspapers are more likely to allow users to comment on articles than are national newspapers. Tweeting news is appropriated only on news sites affiliated with evening tabloids and national morning newspapers. Sharing news through Facebook is 20 times more common than tweeting news or commenting. The majority of news items do not attract any user interaction.
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| 31. |
- Almgren, Susanne, 1967-, et al.
(författare)
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Deltagande användare - i princip och praktik
- 2016
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Ingår i: Människorna, medierna & marknaden. - Stockholm : Wolters Kluwer. - 0375-250X. - 9789138244333 ; , s. 377-401
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 32. |
- Almgren, Susanne, 1967-, et al.
(författare)
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‘Let’s Get Them Involved’ . . . to Some Extent : Analyzing Online News Participation
- 2015
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Ingår i: Social Media + Society. - : Sage Publications. - 2056-3051. ; 1:2, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- The development of social media applications, such as blogs, Facebook, and Twitter, has offered new participatory opportunities for everyday media users. This article contributes to research by looking into one specific aspect of the increasingly more participatory media ecology—the news comment feature. Drawing on a quantitative content analysis of 1,100 news pieces, as well as spaces for user comments, the article reveals both how this emerging public space is shaped by the media company and, later, appropriated by their participating users. Our analysis reveals, for instance, that the online newspaper prefers to allow users to comment on lightweight news such as sports and entertainment. The users, however, prefer to post comments on news covering changes in proximity space, politics, and health care, while also clearly ignoring the most available news pieces (sport and entertainment). In the concluding section, the discrepancy in preferences is discussed.
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| 33. |
- Almgren, Susanne, 1967-, et al.
(författare)
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Steering the Editorial Filter - User Comments as a Negotiated Space for Participation in Online News
- 2014
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Ingår i: ECREA 2014 Lisboa - Communication for empowerment: citizens, markets, innovations. ; , s. 28-
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Konferensbidrag (refereegranskat)abstract
- The development of social media applications, such as blogs, Facebook and Twitter, has offered new participatory opportunities to everyday media users. In some respects, this also marks a transformation of public space, as the broadcasting era’s “audiences” nowadays also can take on the role as participating “co-creators”. Or to put it slightly differently: Contemporary media landscape allows for new forms of coexistence between producer and user generated content. For traditional media companies, this transformation has brought both challenges and opportunities. User generated content has always played a part in media production, but the current media situation has certainly made it a more salient feature. Among online newspapers, specifically, the new opportunities to include users’ participatory practices have taken different forms. For instance, they nowadays allow for convenient Facebook-liking and users linking blog posts to articles. They also spend both time and energy on making it easier for readers to get in touch with them in order to provide pictures, information, corrections, etc. Within this context of offering new, participatory opportunities to the previous “readers”, online newspapers have also come to adapt to and develop on one specifically salient strategy: To allow readers/users to comment on articles online. Media research has already paid attention to user comments as a participatory practice. These studies have typically looked into what technological features for participation that are offered and how they enable and limit users’ participatory practices (cf. Domingo et al., 2008; Hermida & Thurman, 2008). In this paper, we take on a slightly different approach. Firstly, the paper looks into the conditions for participation in terms of topics: What content are users allowed to comment on? How do content characteristics differ between news that are made available and news that are withheld from comments? After having mapped these conditions for participation we – secondly –analyze how users actually navigate within this (conditioned) space: What news are they interested in commenting on? How does commenting vary between different kinds of articles? These questions are answered by help of an analysis of 1.100 news items and their adjacent user interface in an online news site (affiliated with a professionally produced, local newspaper). In terms of methodology we apply quantitative content analysis. Our analysis reveals that the participatory space offered to the readers is geared towards light news, whereas users themselves have clear preferences for commenting news concerning changes in their local environment, about general national politics and welfare issues. The paper concludes with a discussion on potential explanations as to why this discrepancy exists and it also further reflects on its potential implications for users’ participatory practices.
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| 34. |
- Almgren, Susanne, 1967-
(författare)
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Users and producers : Online News as Mediated Participation
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of this thesis is to illuminate principles that guide mediated participation, taking place through the interplay between users and news producers. Therefore, the study focuses both how spaces for participation are structured (by news producers) and those that exert participatory practices (news users). The research design thus has an approach that ties together analytical strands that previously have been studied separately. The research questions concern how the conditions comprising mediated participation – in terms of opportunities for users’ participatory practices – differ between (1a) various types of online news sites, and (1b) various types of news, as well as how users exercise participatory practices (2a) on various types of news sites, and (2b) in connection to various types of news. The last research question (3) concerns how users express the connection to news producers, through participatory practices within participatory spaces. The thesis includes four papers, that together answer the research questions by applying content and text analyses to various types of news sites (big city national, local rural area, morning broadsheets and evening tabloids) and its content: news articles and features for user participation, such as comments and sharing news through social media (i.e., Facebook and Twitter).The results show that users and news producers take diverging approaches to user participation adjacent to online news. This is illustrated by the fact that the categories of news that users are most often permitted to interact with, coincide precisely with the news that users tend to decline to interact with, while the news categories that users tend to interact with (when given the chance) occur comparatively sparse. The results also show that news producers are much more prone to permit users to share news through social media, than to permit them to comment news on the news site. Almost all news are made to permit users to share news through Facebook and Twitter, whereas commenting news is substantially more restricted, and even more so among big city national news sites than among local rural area news sites. When it concerns user practices, users share news on Facebook 20 times more often than they share news through Twitter or comment news on news sites. Tweeting news almost only occurs in news sites affiliated with big city national newspapers, and most prominently so when it concerns evening tabloids. This means (when controlling for differences in circulation) that commenting as a user practice tend to have a more local character than tweeting news, with its more national focus.The connection between users and news producers is shaped by the approach these groups of actors take to each other, under different circumstances. Sharing news through Facebook and commenting on news sites, are not interchangeable practices. Nor is tweeting news from a news site affiliated with national tabloid compared to from a local morning newspaper. And although it is well known from extant research that producers hold hesitant views concerning users’ influence over content, users also express distrust when it concerns how professional media practices allow various actors salience in the media. These ideas primarily concern “elites” versus “commoners”, differences between public service and commercial media, regulations and media, including roles, genres, and formats. These ideas also concern whether representational principles should guide media representation or if certain views should be excluded, whether journalists’ political views affect media performance, and how crime news should be presented in terms of what events are published and representations of victims and perpetrators. Overall, the thesis illustrates that there are connections between various forms of electronic communication (i.e., commenting and sharing news through Facebook and Twitter), and the specific contextual and social settings that news sites are embedded within, with its specific situated audience, shaping the connections between users and news producers.
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| 35. |
- Andermann, Tobias, et al.
(författare)
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Allele Phasing Greatly Improves the Phylogenetic Utility of Ultraconserved Elements
- 2019
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Ingår i: Systematic Biology. - : Oxford University Press (OUP). - 1063-5157 .- 1076-836X. ; 68:1, s. 32-46
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Tidskriftsartikel (refereegranskat)abstract
- Advances in high-throughput sequencing techniques now allow relatively easy and affordable sequencing of large portions of the genome, even for nonmodel organisms. Many phylogenetic studies reduce costs by focusing their sequencing efforts on a selected set of targeted loci, commonly enriched using sequence capture. The advantage of this approach is that it recovers a consistent set of loci, each with high sequencing depth, which leads to more confidence in the assembly of target sequences. High sequencing depth can also be used to identify phylogenetically informative allelic variation within sequenced individuals, but allele sequences are infrequently assembled in phylogenetic studies. Instead, many scientists perform their phylogenetic analyses using contig sequences which result from the de novo assembly of sequencing reads into contigs containing only canonical nucleobases, and this may reduce both statistical power and phylogenetic accuracy. Here, we develop an easy-to-use pipeline to recover allele sequences from sequence capture data, and we use simulated and empirical data to demonstrate the utility of integrating these allele sequences to analyses performed under the multispecies coalescent model. Our empirical analyses of ultraconserved element locus data collected from the South American hummingbird genus Topaza demonstrate that phased allele sequences carry sufficient phylogenetic information to infer the genetic structure, lineage divergence, and biogeographic history of a genus that diversified during the last 3 myr. The phylogenetic results support the recognition of two species and suggest a high rate of gene flow across large distances of rainforest habitats but rare admixture across the Amazon River. Our simulations provide evidence that analyzing allele sequences leads to more accurate estimates of tree topology and divergence times than the more common approach of using contig sequences.
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| 36. |
- Andersson, Agnes, et al.
(författare)
-
Headache Before and After Endoscopic Transsphenoidal Pituitary Tumor Surgery: A Prospective Study
- 2022
-
Ingår i: Journal of Neurological Surgery Part B-Skull Base. - : Georg Thieme Verlag KG. - 2193-6331 .- 2193-634X. ; 83:suppl. 2
-
Tidskriftsartikel (refereegranskat)abstract
- Objective Headache is a common symptom among patients with pituitary tumors, as it is in the general population. The aim of the study was to investigate headache as a symptom in patients with pituitary tumors before and 6 months after endoscopic transsphenoidal surgery (TSS). Design This is a prospective observational cohort study. Setting This study was conducted at university tertiary referral hospital. Participants A total of 110 adult patients underwent endoscopic TSS for pituitary tumors. Main Outcome Measures The Migraine Disability Assessment (MIDAS) questionnaire was used before and 6 months after surgery for the assessment of headache. Clinical variables with potential influence on headache were analyzed. Results Sixty-eight (62%) patients experienced headaches at least once during the 3 months before surgery. Thirty (27%) patients reported disabling headache before surgery, with younger age being an independent associated factor ( p <0.001). In patients with disabling headache before surgery, the median (interquartile range) MIDAS score improved from 78 (27-168) to 16 (2-145; p =0.049), headache frequency decreased from 45 (20-81) to 14 (4-35) days ( p =0.009), and headache intensity decreased from 6 (5-8) to 5 (4-7) ( p =0.011) after surgery. In total, 16 of the 30 (53%) patients reported a clinically relevant improvement and five (17%) a clinically relevant worsening. Four (5%) patients developed new disabling headache. No predictor for postoperative improvement of headache was identified. Conclusion In this prospective study, the results show that disabling headache improves following endoscopic TSS in a subset of patients with pituitary tumors. However, no predictive factors for improvement could be identified.
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| 37. |
- Andersson, Erik
(författare)
-
Det politiska rummet : villkor för situationspolitisk socialisation i en nätgemenskap av och för ungdomar
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim is to analyse the institutional character of, and the on-going communication in, a net community organised by and for young people. This is achieved using terms of conditions for situational political socialisation – a situation in a specific context in which the participants, within the battle between different groups attempting to organise society through interaction and action, adopt political preferences and skills. The thesis builds on agonism, a political theory in which controversy and struggle are viewed as prerequisites for human life that uses language as a political act. The net community, as an institution, contingently depends on political rebirth via action and communication. The use of language creates places that give the institution meaning while at the same time the institution claims the participants and their creation of meaning. Black Heart, the analysed net community, is a quasi-public space for and by young people aged between 14 and 28 years. It is a cultural community where political conversations take place among other kinds of communication. The institutional character of Black Heart and ten politically controversial conversations are analysed, using a case study method that applies web content analysis and computer mediated discourse analysis. There is a strong institutional framework operating in the political text conversations of Black Heart, the participants are governed by the institution and the participants govern each other. The political communication is characterised by revealing and arguing for political interest. To challenge is the dominant category of political action which constitutes political subjects that are offensive, argumentative and polemic. Political communication and the on-going interaction generate an educational situation in which the participants are expected to be content oriented, argumentative, expressive, communicative and polemic.
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| 38. |
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| 39. |
- Andersson, Magnus, et al.
(författare)
-
Medierad social interaktion
- 2017
-
Ingår i: Sociala medier – vetenskapliga perspektiv. - 9789140694805 ; , s. 21-35
-
Bokkapitel (refereegranskat)
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| 40. |
- Antonsson, Jakob, et al.
(författare)
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Modeling Colloidal Particle Aggregation Using Cluster Aggregation with Multiple Particle Interactions
- 2024
-
Ingår i: Journal of Physical Chemistry B. - 1520-6106 .- 1520-5207. ; 128:18, s. 4513-4524
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, we investigate the aggregation dynamics of colloidal silica by generating simulated structures and comparing them to experimental data gathered through scanning transmission electron microscopy (STEM). More specifically, diffusion-limited cluster aggregation and reaction-limited cluster aggregation models with different functions for the probability of particles sticking upon contact were used. Aside from using a constant sticking probability, the sticking probability was allowed to depend on the masses of the colliding clusters and on the number of particles close to the collision between clusters. The different models of the sticking probability were evaluated based on the goodness-of-fit of spatial summary statistics. Furthermore, the models were compared to the experimental data by calculating the structures’ fractal dimension and mass transport properties from simulations of flow and diffusion. The sticking probability, depending on the interaction with multiple particles close to the collision site, led to structures most similar to the STEM data.
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| 41. |
- Arvemo, Tobias, 1970-, et al.
(författare)
-
Att utveckla Lysekils centrum tillsammans : utmaningar och möjligheter
- 2018
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna studie designades och analyserades av Högskolan Väst 2016-2017. Undersökningen kompletterar den besökar- och boendestudie som Högskolan Väst tidigare genomförde inom projektet i Lysekil under sensommaren 2016 (se Högskolan Väst Rapport 2 Urban Platsinnovation Besökar- och boendestudie i Lysekil sensommaren 2017). Denna studie genomfördes under tiden 26 maj - 11 augusti 2017 med 363 svarande respondenter, varav 165 var besökare och 198 permanent boende i Lysekil. Syftet med studien var att öka kunskapen om både besökares och boendes uppfattningar om Lysekil. Högskolan Väst har även genomfört en intervjustudie med centrumaktörer i Lysekil under 2017 (se Högskolan Väst Rapport 4 Urban Platsinnovation Att utveckla Lysekils centrum tillsammans - utmaningar och möjligheter). Studierna1 avser även att bidra gränsöverskridande inspiration samt vara ett underlag för planering och utveckling av kommande centrumutvecklande aktiviteter såväl inom som utanför projektets regi.Undersökningen visar att besökare framför allt kommer till Lysekil för att koppla av och är nöjda med sitt besök i Lysekil samt med service och utbud, stadsmiljö och faciliteter. En stor majoritet av besökarna har besökt Lysekil innan och anger att de kommer att besöka Lysekil igen. Av de besökare är det 88% som sannolikt kommer rekommendera andra ett besök i Lysekil. Ungefär hälften av besökarna bor mer än 10 mil från Lysekil.De permanent boende i Lysekil är också nöjda med utbudet av restauranger, kvalitén på både maten och servicen. De boende var också nöjda med servicen i butikerna men ställde sig neutrala till utbudet av butiker. Det största missnöjet bland de permanent boende i Lysekil finns kring parkeringssituationen.Studien är i stort samstämmig med den besökar- och boendeundersökning som genomfördes 2016.Ett stort antal förbättringsförslag ges av respondenterna och finns redovisade i rapporten. Dessa förslag är allt från konkreta till visionära.Det är vår rekommendation att denna rapport ihop med rapporten från undersökningen 2016 (se Högskolan Västs Rapport 2) delges och diskuteras med de aktörer och nätverk som finns i Lysekil i arbetet i att ta fram nya centrumutvecklande aktiviteter.
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| 42. |
- Arvemo, Tobias, 1970-, et al.
(författare)
-
Besökar- och boendestudie i Lysekil sensommaren 2016
- 2016
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- En studie av besökare och boende i Lysekil genomfördes med 279 svarande respondenter under tiden 26 juli - 14 september 2016. Syftet med studien var att öka kunskapen om både boendes och besökandes uppfattningar om Lysekil.Studien syftar även till att ge ett bidrag till ett större underlag för och gränsöverskridande inspiration till planering och utveckling av kommande centrumutvecklande aktiviteter såväl inom som utanför projektets regi.151 besökande och 128 permanent boende besvarade undersökningen.Undersökningen visar att de besökande framför allt kommer till Lysekil för att koppla av och är nöjda med sitt besök i Lysekil samt med service och utbud, stadsmiljö och faciliteter. En stor majoritet av besökarna har besökt Lysekil innan och anger att man kommer att besöka Lysekil igen. Av de besökande är det 97% som sannolikt kommer rekommendera andra ett besök i Lysekil. Ungefär hälften av de besökande bor mer än 10 mil från Lysekil.Bland de permanent boende i Lysekil är man också nöjd med utbudet av restauranger, kvalitén på restaurangmaten samt service på restaurang och i butik. Man är också nöjd med stadsmiljön, skyltning/vägvisning, hur lätt det är att ta sig till Lysekil, faciliteter och kvalitén på boende. En majoritet av de tillfrågade är missnöjda med parkeringssituationen i Lysekil. Utbudet av butiker och uteliv har mer utspridda svar.Samtliga respondenter fick tillfälle att ge förslag på vad som kan förbättras i Lysekils centrum. Av 279 respondenter gav 123 besökande och 114 boende i Lysekil förbättringsförslag. Förslagen, som är både konkreta och visionära, rör huvudsakligen följande sju teman; Trivsel och intryck av stadsmiljön, Infrastruktur, parkering mm, Husbilsparkering/ställplatser, Information och Skyltning, Aktiviteter/evenemang, Utbud och Övrigt.Vår rekommendation är att, de nätverk och aktörer som är anslutna till projektet i Lysekil, tar del av och diskuterar studiens resultat inför framtida centrumutvecklande aktiviteter. Vi rekommenderar även att man åtgärdar de förbättringsförslag som går att genomföra på kort sikt och redan nu diskuterar de mer långsiktiga och eventuellt resurstunga förbättringsförslag.
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| 43. |
- Arvemo, Tobias, 1970-, et al.
(författare)
-
Besökar- och boendestudie i Lysekil sommaren 2017
- 2018
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna studie designades och analyserades av Högskolan Väst 2016-2017. Undersökningen kompletterar den besökar- och boendestudie som Högskolan Väst tidigare genomförde inom projektet i Lysekil under sensommaren 2016 (se Högskolan Väst Rapport 2 Urban Platsinnovation Besökar- och boendestudie i Lysekil sensommaren 2017). Denna studie genomfördes under tiden 26 maj - 11 augusti 2017 med 363 svarande respondenter, varav 165 var besökare och 198 permanent boende i Lysekil. Syftet med studien var att öka kunskapen om både besökares och boendes uppfattningar om Lysekil. Högskolan Väst har även genomfört en intervjustudie med centrumaktörer i Lysekil under 2017 (se Högskolan Väst Rapport 4 Urban Platsinnovation Att utveckla Lysekils centrum tillsammans - utmaningar och möjligheter). Studierna1 avser även att bidra gränsöverskridande inspiration samt vara ett underlag för planering och utveckling av kommande centrumutvecklande aktiviteter såväl inom som utanför projektets regi. Undersökningen visar att besökare framför allt kommer till Lysekil för att koppla av och är nöjda med sitt besök i Lysekil samt med service och utbud, stadsmiljö och faciliteter. En stor majoritet av besökarna har besökt Lysekil innan och anger att de kommer att besöka Lysekil igen. Av de besökare är det 88% som sannolikt kommer rekommendera andra ett besök i Lysekil. Ungefär hälften av besökarna bor mer än 10 mil från Lysekil. De permanent boende i Lysekil är också nöjda med utbudet av restauranger, kvalitén på både maten och servicen. De boende var också nöjda med servicen i butikerna men ställde sig neutrala till utbudet av butiker. Det största missnöjet bland de permanent boende i Lysekil finns kring parkeringssituationen. Studien är i stort samstämmig med den besökar- och boendeundersökning som genomfördes 2016. Ett stort antal förbättringsförslag ges av respondenterna och finns redovisade i rapporten. Dessa förslag är allt från konkreta till visionära. Det är vår rekommendation att denna rapport ihop med rapporten från undersökningen 2016 (se Högskolan Västs Rapport 2) delges och diskuteras med de aktörer och nätverk som finns i Lysekil i arbetet i att ta fram nya centrumutvecklande aktiviteter
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| 44. |
- Arvemo, Tobias, 1970-, et al.
(författare)
-
En gränsöverskridande workshop om : Hvordan kan vi bruke undersøkelser til å skape et bedre sentrum?
- 2016
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- En gränsöverskridande workshop om Hvordan kan vi bruke undersøkelser til å skape et bedre sentrum? genomfördes den 27 oktober 2016 i Fredrikstad under stormöte 2 i projektet Urban Platsinnovation. Syftet med workshopen var att näringsidkare och kommuner i Sverige och Norge ska knyta kontakter och utbyta erfarenheter. Under workshopen diskuterade de 62 deltagarna undersökningar som beslutsunderlag samt deltagande och samverkan för utveckling av centrum. I anslutning till workshopen redogjordes för tre i projektet genomförda studier. Workshopens genomförande och dokumentation syftar till att ge ett underlag och gränsöverskridande inspiration till planering och utveckling av kommande centrumutvecklande aktiviteter såväl inom som utanför projektets regi.Workshopsdeltagarna får idag information om kunder, besökare och medborgare genom olika spridda kanaler; via kartläggningar, handelsutredningar, nationella näringslivstudier, egna undersökningar via sociala medier, webbstatistik, kommunens kundtjänst, medborgarkontor, medborgardialoger (brukermedvirkning), samtal och personlig kontakt, sociala möten och nätverk, cafédialoger/dialog med organisationer, företag och föreningar, mässor och genom nyheter i dagstidning (avis). Samtliga deltagare menar att studier av det slag som presenterades vid workshopen är mycket viktiga. Presenterade studier är intressanta då de visar på fakta och statistik – vilket inte alltid stämmer med vad man tror eller hört. Faktaunderlag är viktigt för att kunna arbeta framåt. Kritisk och djupare analys, koordinering, samordning och bättre kommunikation kring studier och resultat behövs. Deltagarna framhåller vikten av att dels ha tillgång till ett kvantitativt datamaterial i form av besöksdata som kan kopplas till annan data såsom omsättning, dels till ett kvalitativt material som fokuserar på vem besökaren är, orsaker till besök samt vilka önskemål besökare men även boende har.Det råder en stark vilja till samverkan mellan de olika aktörerna för centrumutvecklingen. I vissa fall och i vissa kommuner fungerar samverkan riktigt bra mellan framför allt kommun och butiksägare. Dock inses vikten av en bredare representativitet i grupperingar för centrumutvecklingen. Nya aktörer välkomnas samt tydliga strategier och roller. Viljan att engagera sig och delta finns, och många ser möjligheten att genom detta projekt få till en hel del bra grundarbete. Bra exempel ges på kanaler och plattformar för informationsspridning och kommunikation och deltagarna ser gärna en fortsatt utveckling av dessa för samverkan och koordinering av olika aktiviteter.
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| 45. |
- Arvemo, Tobias, 1970-, et al.
(författare)
-
Lessons Learned From A Cross-Sector Development Project : An Integrative Research Approach
- 2018
-
Ingår i: INTED 2018. - : IATED. - 9788469794807 ; , s. 3914-3922
-
Konferensbidrag (refereegranskat)abstract
- This paper draws on the experiences of work-integrated learning from a Swedish-Norwegian cross-sector research project where actors from university, industry, government and volunteer sector collaborate on city center development. The empirical setting of the present study consists of six smaller cities in rural municipalities with limited resources and experiences of collaboration with higher education institutions. The following research question is addressed: How can research and development projects serve as a vehicle for facilitating mutual knowledge exchange between academia and society in cross-sector and rural collaboration contexts? The aim is hence to suggest a tentative collaboration model that identify and integrate knowledge flows between actors involved in cross-sector collaborations in such setting. To gain deep insights in the complex dynamics of project collaboration we applied a mixed methods approach including surveys, structured, in-depth qualitative interviews, observations, workshops and student projects. The data collection was performed during 2016-2017. Findings indicate that trust, continuity, and relationship building are the basis vital for successful creation, development and maintenance of knowledge flows. Furthermore, there is a need to develop an integrative tool box with different methodological tools, work practices and strategies to plan, perform, compile to leverage the knowledge flows and coproduce sustainable results. Our tentative model aims to illustrate conceptualize lessons learned on work-integrated learning and collaboration with academia. We discuss how the model may support co-creative and mutual results over time.
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| 46. |
- Arvemo, Tobias, 1970-, et al.
(författare)
-
Samverkan och utveckling i Gamlebyen
- 2017
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Högskolan Västs Rapport 3 - Samverkan och utveckling i Gamlebyen består av en studie av Gamlebyen Fredrikstads kommune, Norge. Denna studie baseras på 18 djupintervjuer med 21 aktörer i och kring Gamlebyen, Fredrikstads kommune, som genomfördes perioden november 2016 - februari 2017 samt en webb-enkät med 22 elever (blivande hantverkare) vid Plus-skolen i Gamlebyen i mars 2017. Syfte med studien var att fånga aktörernas uppfattning om Gamlebyens attraktivitet, vision, nuläge och utmaningar i samverkan. Syftet var även att ge förslag för samarbete och styrning som potential för framtida näringsutveckling och engagemang. Vidare syftar studien långsiktigt till ge ett underlag och gränsöverskridande inspiration för planering och utveckling av kommande centrumutvecklande aktiviteter såväl inom som utanför projektets regi.Studien visar på den mångfald av aktörer som verkar i Gamlebyen och den brist på samarbete och kommunikation som denna mångfald ger upphov till. Området saknar en gemensam vision om Gamlebyen skall utvecklas och bevaras. Sammantaget gör detta att Gamlebyen hämmas i sin utveckling och inte får den attraktionskraft som området har potential för. Många aktörer känner att kommunens satsningar på andra områden i Fredrikstad har haft ett negativt inflytande på området.För att Gamlebyen skall kunna nå sin potential behövs en samordnande roll av typen centrumutvecklare som koordinerar dels internt i Gamlebyen men även verkar in mot kommun och centrum för ökad samordning. En gemensam intern kommunikationsplattform för aktörerna i Gamlebyen är av stor vikt för att öka kommunikationen i området och samordna aktuell och korrekt information.
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| 47. |
- Batista, R., et al.
(författare)
-
Phylogenomics and biogeography of the world's thrushes (Aves, Turdus): new evidence for a more parsimonious evolutionary history
- 2020
-
Ingår i: Proceedings. Biological sciences. - : The Royal Society. - 1471-2954. ; 287:1919
-
Tidskriftsartikel (refereegranskat)abstract
- To elucidate the relationships and spatial range evolution across the world of the bird genus Turdus (Aves), we produced a large genomic dataset comprising ca 2 million nucleotides for ca 100 samples representing 53 species, including over 2000 loci. We estimated time-calibrated maximum-likelihood and multispecies coalescent phylogenies and carried out biogeographic analyses. Our results indicate that there have been considerably fewer trans-oceanic dispersals within the genus Turdus than previously suggested, such that the Palaearctic clade did not originate in America and the African clade was not involved in the colonization of the Americas. Instead, our findings suggest that dispersal from the Western Palaearctic via the Antilles to the Neotropics might have occurred in a single event, giving rise to the rich Neotropical diversity of Turdus observed today, with no reverse dispersals to the Palaearctic or Africa. Our large multilocus dataset, combined with dense species-level sampling and analysed under probabilistic methods, brings important insights into historical biogeography and systematics, even in a scenario of fast and spatially complex diversification.
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| 48. |
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| 49. |
- Bengtsson, Jenny, et al.
(författare)
-
Impact of non-solvents in the tetrabutylammonium acetate : dimethyl sulfoxide-cellulose system
- 2016
-
Ingår i: The 7th Workshop on cellulose, regenerated cellulose and cellulose derivatives. ; , s. 19-22
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This work examines the potential of tetrabutylammonium acetate: dimethyl sulfoxide (TBAAc:DMSO) as a solvent used in a process for producing man-made cellulose fibers. The tolerance towards nonsolvents is an important step to evaluate the recyclability of the solvent. TBAAc:DMSO was in this work further confirmed to be an efficient solvent for cellulose. Non-solvent tolerance depended on cellulose concentration, TBAAc:DMSO ratio and type of non-solvent. There was no significant change in mechanical properties for filaments regenerated from solutions containing 2 wt% non-solvent compared to those spun from virgin solvent. With 4 wt% ethanol present in solution very brittle filaments were produced, not suitable for use as textile fibers.
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| 50. |
- Bengtsson, Jenny, et al.
(författare)
-
Understanding the Inhibiting Effect of Small-Molecule Hydrogen Bond Donors on the Solubility of Cellulose in Tetrabutylammonium Acetate/DMSO
- 2017
-
Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 121:50, s. 11241-11248
-
Tidskriftsartikel (refereegranskat)abstract
- Certain ionic liquids are powerful cellulose solvents, but tend to be less effective when small-molecule hydrogen bond donors are present. This is generally attributed to competition with cellulose for hydrogen bonding opportunities to the anion of the ionic liquid. We show that the solubility of cellulose in dimethyl sulfoxide solutions of tetrabutylammonium acetate is less strongly affected by water than by ethanol on a molar basis, contrary to what can be expected based on hydrogen bond stoichiometry. Molecular dynamics simulations indicate that the higher tolerance to water is due to water-cellulose interactions that improves solvation of cellulose and, thereby, marginally favors dissolution. Through Kirkwood-Buff theory we show that water, but not ethanol, improves the solvent quality of DMSO and partly compensates for the loss of acetate-cellulose hydrogen bonds.
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