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| 2. |
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| 3. |
- Adepu, Saritha, et al.
(författare)
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Salivary biglycan-neo-epitope-BGN262: A novel surrogate biomarker for equine osteoarthritic sub-chondral bone sclerosis and to monitor the effect of short-term training and surface arena
- 2023
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Ingår i: Osteoarthritis and Cartilage Open. - : Elsevier BV. - 2665-9131. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- Objective: We aimed to delineate a novel soluble Biglycan Neo-epitope-BGN262 in saliva from young reference and osteoarthritic horses in conjunction with the influence of short-term training exercise, riding surface hardness, circadian rhythm, and feeding on its soluble levels. Design: A custom-made inhibition ELISA was used for the quantification of BGN262 in saliva. Cohort 1: A cross-sectional study comprising reference (N = 19) and OA horses (N = 9) with radiographically classified subchondral bone sclerosis. Receiver operating characteristic curve analysis was performed to evaluate the robustness of BGN262. Cohorts 2 (N = 5) & 3 (N = 7): Longitudinal studies of sampling during a short-term training exercise (sand-fibre) and a cross-over design of short-training exercise on 2 different riding arenas (sand and sand-fibre), respectively. Capillary western immunoassay was used to determine the BGN262 molecular size in a selection of saliva samples collected from cohort 1. Results: Cohort 1: Salivary BGN262 levels were significantly higher in the OA group. The Receiver operating characteristic curve analysis showed an area under the curve of 0.8304 [0.6386 to 1.022], indicating a good separation from the reference group. Cohorts 2 & 3: Salivary BGN262 levels significantly changed during the exercise on sand and sand-fibre arena, with a trend towards higher levels for sand-fibre. The size of the BGN262 fragment determined by Capillary western assay was 18 kDa. Conclusions: The data presented show saliva BGN262 levels as a novel biomarker in evaluating the influence of exercise, and interaction with riding arenas alongside assessing osteoarthritis severity.
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| 4. |
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| 5. |
- Berghammer, Malin, et al.
(författare)
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The impact of anxiety in relation to COVID-19 on the life-situation of young people in Sweden
- 2021
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Ingår i: Quality of Life Research. - : SPRINGER. - 0962-9343 .- 1573-2649. ; 30:SUPPL 1, s. S4-S4
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Aims: In general, COVID-19 symptoms are milder in children than inadults, but the experience of the pandemic could increase anxiety andsignificantly affect the life situation of children and adolescents. Itcould also lead to a long-term negative effect on their health. To studyhow the corona pandemic affected the life situation of children andadolescents in Sweden. Methods: A self-reported online survey wasperformed July–November 2020. Cross-sectional data were collectedusing non-probability and convenience sampling methods. The sample consisted of children 6–14 years and their guardians, and adolescents 15–19 years. The questionnaire covered items regarding the life situation including demographics, school situation, social isolation, and an open-ended question to provide a subjective expression of the living situation. A standardized measurement of anxiety was collected using the Children’s Anxiety Questionnaire (CAQ) (scores range 4–12) and the Numeric Rating Scale (NRS)(scores range 0–10). Data were analyzed by descriptive statistics andwith qualitative manifest content analysis. Results: In total, 1487 participants, 768 children with guardians and 719 adolescents participated. Most of the participants, 754 children (97.2%) and 634 adolescents (89.2%) attended school where a mixture of physical attendance and distance learning was reported by 79 children (10.2%)and 261 adolescents (36.7%). Two children (0.3%) and 298 adolescents (41.9%) reported only having distance learning. A larger proportion of children (n = 339, 43.9%) and adolescents (n = 420,59.2%) reported abstaining from leisure activities, while a minority ofchildren (n = 103, 13%) and adolescent (n = 135, 19%) reportedexperiencing a feeling of ‘social isolation’. These experiences ofchanges in daily routine were prominent in the qualitative result. Social restrictions and loss of contact with older relatives led to fear and anxiety. However, for young children, their lives continued torevolve around the everyday things in life rather than the coronapandemic, for the adolescents; however, their life situation was negatively affected by isolation from peer groups and the loss ofschool routine. Conclusion: The experiences by children due toCOVID-19 in Sweden highlight the importance that children continue living their lives as unchanged as possible and that particularly adolescents need receiving greater support with the maintenance of an educational routine.
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| 7. |
- Borgström, Benedikte, 1968, et al.
(författare)
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A rythmanalytic approach to understand the problematic nature of supply chain integration: The case of a customer ordered production strategy
- 2011
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Ingår i: the 27th IMP conference.
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Konferensbidrag (refereegranskat)abstract
- Implementing a customer ordered production strategy involves changes in supply chain integration compared to if production was based on forecasts of demand. In a study of Volvo Cars’ customer ordered strategy it was found that the degree of implementation changed over time, especially in relation to business cycles. It seems, with reference to statements made by respondents involved in practice at different stages in the supply chain, that there exists different “world views” and logics of action depending of the actors’ position in the chain: A business logic downstream and an industrial logic upstream from the assembler (Volvo Cars split in “manufacturing” and “sales”). Time, space and energy are different in the logics. Transport providers adapt and coordinate activities with logic of their own .To understand time, space and energy we refer to the ideas put forward by Lefebvre on rhythm in everyday life. It is important to be aware of ongoing changes in the everydayness for supply chain integration knowledge. Integration needs to be handled as a process, it is not given by plans and procedures as state.We interpret the empirical findings by applying Lefebvre’s conceptual framework. The approach facilitates a better understanding of the supply chain integration process and potentialities of temporal alignment.
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| 8. |
- Bredenberg, Susanne, et al.
(författare)
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Evaluation of a sieve classification method for characterization of low-dose interactive mixtures
- 2013
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Ingår i: Pharmaceutical development and technology (Print). - : Informa Healthcare. - 1083-7450 .- 1097-9867. ; 18:6, s. 1366-1371
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated a sieve classification method for evaluating carrier materials and particle size fractions, which could be a valuable tool in the early development of pharmaceutical dosage forms containing low-dose interactive mixtures. When developing new products based on interactive mixtures, it is essential to ensure that the drug particles are successfully deagglomerated and have adhered to the carrier particles. In this study, the effect on the demixing potential (DP) of low-dose interactive mixtures was assessed for various carrier particle sizes and surface textures. The model drug used was sodium salicylate and the tested carriers were lactose, mannitol, and isomalt. The results showed that the lowest DPs, i.e. the most mechanically stable mixtures, were obtained with lactose. Furthermore, for interactive mixtures, small carrier particles and/or a narrow carrier particle size range are essential for obtaining a low DP and high homogeneity. Calculation of the DP provided a reliable estimate of the quality of the low-dose interactive mixtures used in this study.
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| 9. |
- Båth, Magnus, 1974, et al.
(författare)
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Nodule detection in digital chest radiography: introduction to the RADIUS chest trial.
- 2005
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Ingår i: Radiation protection dosimetry. - : Oxford University Press (OUP). - 0144-8420 .- 1742-3406. ; 114:1-3, s. 85-91
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Tidskriftsartikel (refereegranskat)abstract
- Most digital radiographic systems of today have wide latitude and are hence able to provide images with a small constraint on dose level. This opens up for an unprejudiced dose optimisation. However, in order to succeed in the optimisation task, good knowledge of the imaging and detection processes is needed. As a part of the European-wide research project 'unification of physical and clinical requirements for medical X-ray imaging'-governed by the Radiological Imaging Unification Strategies (RADIUS) Group-a major image quality trial was conducted by members of the group. The RADIUS chest trial was focused on the detection of lung nodules in digital chest radiography with the aims of determining to what extent (1) the detection of a nodule is dependent on its location, (2) the system noise disturbs the detection of lung nodules, (3) the anatomical noise disturbs the detection of lung nodules and (4) the image background and anatomical background act as pure noise for the detection of lung nodules. The purpose of the present paper is to give an introduction to the trial and describe the framework and set-up of the investigation.
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| 10. |
- Börjesson, Sara, et al.
(författare)
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A software tool for increased efficiency in observer performance studies in radiology.
- 2005
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Ingår i: Radiation protection dosimetry. - : Oxford University Press (OUP). - 0144-8420 .- 1742-3406. ; 114:1-3, s. 45-52
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Tidskriftsartikel (refereegranskat)abstract
- Observer performance studies are time-consuming tasks, both for the participating observers and for the scientists collecting and analysing the data. A possible way to optimise such studies is to perform them in a completely digital environment. A software tool-ViewDEX (Viewer for Digital Evaluation of X-ray images)-has been developed in Java, enabling it to function on almost any computer. ViewDEX is designed to handle several types of studies, such as visual grading analysis (VGA), image criteria scoring (ICS) and receiver operating characteristics (ROC). The results from each observer are saved in a log file, which can be exported for further analysis in, for example, a special software for analysing ROC results. By using ViewDEX for an ROC experiment, an evaluation rate of approximately 200 images per hour can be achieved, compared to approximately 25 images per hour using hard copy evaluation. The results are obtained within minutes of completion of the viewing. The risk of human errors in the process of data collection and analysis is also minimised. The viewer has been used in a major trial containing approximately 2700 images.
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| 11. |
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| 12. |
- Carlsson, Tommy
(författare)
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To Grasp the Unexpected : Information Following a Prenatal Diagnosis of Congenital Heart Defect in the Fetus
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim was to explore experiences and needs of information following a prenatal diagnosis of congenital heart defect, and to assess the quality of publicly available information websites about congenital heart defects. Study I was a qualitative interview study that explored experiences among 11 parents to prenatally diagnosed children. Respondents tried to grasp the facts today while reflecting on the future, and personal contact with medical specialists was valued. The analysis showed that the Web contained an overwhelming amount of information. Study II was a qualitative interview study that explored experiences among 26 females and males 5-15 weeks after a prenatal diagnosis. Respondents hunted for information in a confusing reality, with a need for information about various topics and methods for information delivery. Although high satisfaction with the specialist information was described, the information was considered overwhelming and complex. Supplemental information was sought via the Web. Insufficient information about induced abortions was described. Study III was a quantitative study that explored content and quality of 67 English websites about congenital heart defects. Few websites included information about prenatal aspects, such as pregnancy termination. The overall quality was poor, especially reliability and information about treatment choices. Study IV was a mixed methods study that explored the quality of 10 Swedish websites about congenital heart defects, from the perspectives of 9 assessors with personal experience of a prenatal diagnosis. Quantitative Likert scale assessments were followed by written open-ended questions and focus group discussions. Quantitative assessments represented unfulfilled quality criterion for treatment choices, and partially fulfilled quality criteria for appearance, details, relevance, suitability and overall quality. Websites had significantly different scores for all investigated quality criteria. Various issues were highlighted in the responses to the open-ended questions and during the discussions, including inappropriate advertisements, biased information, poor illustrations, complex language and poor trustworthiness. In conclusion, expectant parents faced with a prenatal diagnosis of congenital heart defect in the fetus try to grasp the unexpected, an attempt that involves difficulties in relation to information. These are present during the consultation with health professionals and when searching for web-based information.
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| 13. |
- Corderfeldt, Anna, et al.
(författare)
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Is blood a necessary component of the perfusate during isolated limb perfusion - a randomized controlled trial
- 2019
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Ingår i: International Journal of Hyperthermia. - : Informa UK Limited. - 0265-6736 .- 1464-5157. ; 36:1, s. 794-800
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Tidskriftsartikel (refereegranskat)abstract
- Background: Isolated limb perfusion (ILP) is a treatment option for malignancies localized to an extremity and is performed by surgical isolation of the limb which is connected to an extracorporeal circulation system. A high concentration of a chemotherapeutic agent is perfused through the limb, while systemic toxicity is avoided. Currently, the use of packed red blood cells in the priming solution is the norm during ILP. The aim of this study was to investigate the possibility to replace an erythrocyte-based prime solution with a crystalloid-based prime solution while maintaining the regional metabolic oxygen demand during ILP. Methods: In a single-center, randomized controlled, non-blinded, non-inferiority clinical trial, 21 patients scheduled for treatment with ILP were included and randomized 1:1 to either an erythrocyte-based prime solution (control) or a crystalloid-based prime solution (intervention). Results: There was a significant difference in lactate level (mmol/L) during the perfusion between the intervention group and the control group (1.6 +/- 0.4 vs. 3.6 +/- 0.7, p = .001). No significant differences in oxygen extraction (%) (22 +/- 11 vs. 14 +/- 4, p = .06), oxygen delivery (ml/min) (90 +/- 49 vs. 108 +/- 38, p = .39), oxygen consumption (ml/min) (14 +/- 2 vs. 14 +/- 5, p = .85), regional central venous saturation (%) (83 +/- 10 vs. 91 +/- 4, p = .07) or INVOS (%) (76 +/- 14 vs. 81 +/- 11, p = .42) were found between the intervention group and the control group. Conclusion: This study showed no significant improvement with the addition of packed red blood cells into the prime solution in ensuring the metabolic oxygen demand in the treated extremity during ILP, and we, therefore, recommend that a crystalloid-based prime solution should be used.
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| 15. |
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| 16. |
- Hauffman, Anna, et al.
(författare)
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Cocreated internet-based stepped care for individuals with cancer and concurrent symptoms of anxiety and depression : Results from the U-CARE AdultCan randomized controlled trial
- 2020
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Ingår i: Psycho-Oncology. - : John Wiley & Sons. - 1057-9249 .- 1099-1611. ; 29:12, s. 2012-2018
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Tidskriftsartikel (refereegranskat)abstract
- Objective The aim was to evaluate the effects of cocreated internet-based stepped care (iCAN-DO) on anxiety, depression, posttraumatic stress, and health-related quality of life (HRQoL) in individuals with cancer and self-reported anxiety and/or depression symptoms, compared with standard care.Methods Clinically recruited individuals with breast, colorectal, or prostate cancer underwent online screening with the Hospital Anxiety and Depression Scale (HADS). Those with anxiety and/or depression symptoms (>7 on any of the HADS subscales) were randomized to iCAN-DO or standard care. iCAN-DO comprised psychoeducation and self-care strategies (step 1) and internet-based cognitive behavioral therapy (iCBT, step 2). Data were collected before randomization and at 1, 4, 7, and 10 months and analyzed with intention-to-treat regression analysis and randomization tests.Results Online screening identified 245 (27%) of 909 individuals who reported anxiety and/or depression symptoms. They were randomized to iCAN-DO (n = 124) or standard care (n = 121). Of them 49% completed the 10-month assessment, and in the iCAN-DO group 85% accessed step 1 and 13% underwent iCBT. iCAN-DO decreased the levels of symptoms of depression (−0.54, 95% confidence interval: −1.08 to −0.01, P < .05) and the proportion of individuals with symptoms of depression (P < .01) at 10 months, compared with standard care, according to HADS. There were no significant effects on anxiety, posttraumatic stress, or HRQoL.Conclusion Internet-based stepped care improves symptoms of depression in individuals with cancer. Further studies are needed to gain knowledge on how to optimize and implement internet-based support in oncology care.
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| 17. |
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| 18. |
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| 19. |
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| 20. |
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| 21. |
- Håkansson, Markus, et al.
(författare)
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Nodule detection in digital chest radiography: summary of the RADIUS chest trial.
- 2005
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Ingår i: Radiation protection dosimetry. - : Oxford University Press (OUP). - 0144-8420 .- 1742-3406. ; 114:1-3, s. 114-20
-
Tidskriftsartikel (refereegranskat)abstract
- As a part of the Europe-wide research project 'Unification of physical and clinical requirements for medical X-ray imaging'-governed by the Radiological Imaging Unification Strategies (RADIUS) Group-a major image quality trial was conducted by members of the group. The RADIUS chest trial aimed at thoroughly examining various aspects of nodule detection in digital chest radiography, such as the effects of nodule location, system noise, anatomical noise, and anatomical background. The main findings of the RADIUS chest trial concerning the detection of a lung nodule with a size in the order of 10 mm can be summarised as: (1) the detectability of the nodule is largely dependent on its location in the chest, (2) the system noise has a minor impact on the detectability at the dose levels used today, (3) the disturbance of the anatomical noise is larger than that of the system noise but smaller than that of the anatomical background and (4) the anatomical background acts as noise to a large extent and is the major image component affecting the detectability of the nodule.
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| 22. |
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| 23. |
- Jenholt Nolbris, Margaretha, 1956, et al.
(författare)
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Young children’s voices in an unlocked Sweden during the COVID-19 pandemic
- 2022
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Ingår i: Scandinavian Journal of Public Health. - : Sage Publications. - 1403-4948 .- 1651-1905. ; 50:6, s. 693-702
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Tidskriftsartikel (refereegranskat)abstract
- Aims: During the COVID-19 pandemic, Sweden was one of the few countries that rejected lockdowns in favour of recommendations for restrictions, including careful hand hygiene and social distancing. Preschools and primary schools remained open. Several studies have shown negative impacts of the pandemic on children, particularly high levels of anxiety. The study aim was to explore how Swedish school-aged children aged 6–14 years, experienced the COVID-19 pandemic and their perceived anxiety.Methods: In total, 774 children aged 6–14 years and their guardians answered an online questionnaire containing 24 questions, along with two instruments measuring anxiety: the Children’s Anxiety Questionnaire and the Numerical Rating Scale. A convergent parallel mixed-methods design was used for analysing the quantitative and qualitative data. Each data source was first analysed separately, followed by a merged interpretative analysis.Results: The results showed generally low levels of anxiety, with no significant sex differences. Children who refrained from normal social activities or group activities (n=377) had significantly higher levels of anxiety. Most of the children were able to appreciate the bright side of life, despite the social distancing and refraining from activities, which prevented them from meeting and hugging their loved ones.Conclusions: These Swedish children generally experienced low levels of anxiety, except those who refrained from social activities. Life was nonetheless mostly experienced as normal, largely because schools remained open. Keeping life as normal as possible could be one important factor in preventing higher anxiety and depression levels in children during a pandemic.
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| 24. |
- Kelfve, Susanne, et al.
(författare)
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Increased alcohol use over the past 20 years among the oldest old in Sweden
- 2014
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Ingår i: Nordic Studies on Alcohol and Drugs. - : SAGE Publications. - 1455-0725 .- 1458-6126. ; 31:3, s. 245-260
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Tidskriftsartikel (refereegranskat)abstract
- AIMS - Increased alcohol consumption among old people, reported in many countries, will likely present a major challenge to public health and policy in the future. In Sweden, current knowledge about old people's alcohol consumption is incomplete because of limited historical data and a dearth of nationally representative studies. We describe the frequency of alcohol consumption among the oldest old in Sweden over a 20-year period by sex, age, education, living situation, mobility and Activities of Daily Living. METHODS - We used repeated cross-sectional survey data from the Swedish Panel Study of Living Conditions of the Oldest Old (SWEOLD), conducted in 1992, 2002 and 2011. The samples were nationally representative of the Swedish population aged 77+, with response rates of 95.4%, 84.4% and 86.2% (total n = 2007). Self-reported consumption frequency was measured with the question How often do you drink alcoholic beverages, such as wine, beer or spirits? RESULTS - Frequency of alcohol consumption increased among the oldest old from 1992 to 2011. The proportion reporting no or less-than-monthly alcohol consumption decreased, whereas the proportion reporting weekly consumption increased. This was true for men, women and most age and educational groups. The period change in consumption frequency was not explained by changes in demographic factors, living situation or functional capacity during the study period. CONCLUSIONS - Alcohol use increased among the oldest old in Sweden during the 20-year study period. More liberal attitudes toward alcohol could contribute to the increased use. The increase in weekly alcohol consumers suggests an increase in the number of older risk consumers.
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| 25. |
- Lanhede, B, et al.
(författare)
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The influence of different technique factors on image quality of chest radiographs as evaluated by modified CEC image quality criteria.
- 2002
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Ingår i: The British journal of radiology. - : British Institute of Radiology. - 0007-1285 .- 1748-880X. ; 75:889, s. 38-49
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Tidskriftsartikel (refereegranskat)abstract
- The Commission of the European Communities (CEC) research project "Predictivity and optimisation in medical radiation protection" addressed fundamental operational limitations in existing radiation protection mechanisms. The first part of the project aimed at investigating (1) whether the CEC image quality criteria could be used for optimization of a radiographic process and (2) whether significant differences in image quality based on these criteria could be detected in a controlled project with well known physical and technical parameters. In the present study, chest radiographs on film were produced using healthy volunteers. Four physical/technical parameters were varied in a carefully controlled manner: tube voltage (102 kVp and 141 kVp), nominal speed class (160 and 320), maximum film density (1.3 and 1.8) and method of scatter reduction (grid (R=12) and air gap). The air kerma at the entrance surface was measured for all patients and the risk-related dose H(Golem), based on calculated organ-equivalent dose conversion coefficients and the measured entrance air kerma values, was calculated. Image quality was evaluated by a group of European expert radiologists using a modified version of the CEC quality criteria. For the two density levels, density level 1.8 was significantly better than 1.3 but at the cost of a higher patient radiation exposure. The correlation between the number of fulfilled quality criteria and H(Golem) was generally poor. An air gap technique resulted in lower doses than scatter reduction with a grid but provided comparable image quality. The criteria can be used to highlight optimum radiographic technique in terms of image quality and patient dose, although not unambiguously. A recommendation for good radiographic technique based on a compromise between image quality and risk-related radiation dose to the patient is to use 141 kVp, an air gap, a screen-film system with speed 320 and an optical density of 1.8.
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| 26. |
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| 27. |
- Mattsson, Brady J., et al.
(författare)
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Enhancing monitoring and transboundary collaboration for conserving migratory species under global change : The priority case of the red kite
- 2022
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Ingår i: Journal of Environmental Management. - : Elsevier BV. - 0301-4797. ; 317
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Forskningsöversikt (refereegranskat)abstract
- Calls for urgent action to conserve biodiversity under global change are increasing, and conservation of migratory species in this context poses special challenges. In the last two decades the Convention on the Conservation of Migratory Species of Wild Animals (CMS) has provided a framework for several subsidiary instruments including action plans for migratory bird species, but the effectiveness and transferability of these plans remain unclear. Such laws and policies have been credited with positive outcomes for the conservation of migratory species, but the lack of international coordination and on-ground implementation pose major challenges. While research on migratory populations has received growing attention, considerably less emphasis has been given to integrating ecological information throughout the annual cycle for examining strategies to conserve migratory species at multiple scales in the face of global change. We fill this gap through a case study examining the ecological status and conservation of a migratory raptor and facultative scavenger, the red kite (Milvus milvus), whose current breeding range is limited to Europe and is associated with agricultural landscapes and restricted to the temperate zone. Based on our review, conservation actions have been successful at recovering red kite populations within certain regions. Populations however remain depleted along the southern-most edge of the geographic range where many migratory red kites from northern strongholds overwinter. This led us to a forward-looking and integrated strategy that emphasizes international coordination involving researchers and conservation practitioners to enhance the science-policy-action interface. We identify and explore key issues for conserving the red kite under global change, including enhancing conservation actions within and outside protected areas, recovering depleted populations, accounting for climate change, and transboundary coordination in adaptive conservation and management actions. The integrated conservation strategy is sufficiently general such that it can be adapted to inform conservation of other highly mobile species subject to global change.
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| 28. |
- Mattsson, Lars, et al.
(författare)
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Dust-driven mass loss from carbon stars as a function of stellar parameters : II. Effects of grain size on wind properties
- 2011
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 533, s. A42-
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Tidskriftsartikel (refereegranskat)abstract
- Context. It is well established that the winds of carbon-rich AGB stars (carbon stars) can be driven by radiation pressure on grains of amorphous carbon and collisional transfer of momentum to the gas. This has been demonstrated convincingly by different numerical wind models that include time-dependent dust formation. To simplify the treatment of dust opacities, radiative cross sections are usually computed using the assumption that the dust grains are small compared to wavelengths around the stellar flux maximum. Considering the typical grain sizes that result from these models, however, the applicability of this small-particle limit (SPL) seems questionable.Aims. We explore grain size effects on wind properties of carbon stars, using a generalized description of radiative cross sections valid for particles of arbitrary sizes. The purpose of the study is to investigate under which circumstances the SPL may give acceptable results, and to quantify the possible errors that may occur when the SPL does not hold.Methods. The time-dependent description of grain growth in our detailed radiation-hydrodynamical models gives information about dust particle radii in every layer at every instant of time. Theses grain radii are used for computing opacities and determining the radiative acceleration of the dust-gas mixture. From the large number of models presented in the first paper of this series (based on SPL dust opacities) we selected two samples, i.e., a group of models with strong, well-developed outflows that are probably representative of the majority of wind-forming models, and another group, close to thresholds in stellar parameter space for dust-driven winds, which are referred to as critical cases.Results. We show that in the critical cases the effect of the generalized description of dust opacities can be significant, resulting in more intense mass loss and higher wind velocities compared to models using SPL opacities. For well-developed winds, however, grain size effects on mass-loss rates and wind velocities are found to be small. Both groups of models tend towards lower degrees of dust condensation compared to corresponding SPL models, owing to a self-regulating feedback between grain growth and radiative acceleration. Consequently, the "dust-loss rates" are lower in the models with the generalized treatment of grain opacities.Conclusions. We conclude that our previous results on mass-loss rates obtained with SPL opacities are reliable within a wide region of stellar parameter space, except for critical cases close to thresholds of dust-driven outflows where SPL models will tend to underestimate the mass-loss rates and wind velocities.
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| 29. |
- Mattsson, Lars, 1974-, et al.
(författare)
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Dust driven mass loss from carbon stars as a function of stellar parameters I : A grid of solar-metallicity wind models
- 2010
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 509:1, s. 13-
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Tidskriftsartikel (refereegranskat)abstract
- Context. Knowing how the mass loss of carbon-rich AGB stars depends on stellar parameters is crucial for stellar evolution modelling, as well as for the understanding of when and how circumstellar structures emerge around these stars, e.g., dust shells and so-called detached shells of expelled gas.Aims. The purpose of this paper is to explore the stellar parameter space using a numerical radiation hydrodynamic (RHD) model of carbon-star atmospheres, including a detailed description of dust formation and frequency-dependent radiative transfer, in order to determine how the mass loss of carbon stars changes with stellar parameters.Methods. We have computed a grid of 900 numeric dynamic model atmospheres (DMAs) using a well-tested computer code. This grid of models covers most of the expected combinations of stellar parameters, which are the stellar temperature, the stellar luminosity, the stellar mass, the abundance of condensible carbon, and the velocity amplitude of the pulsation.Results. The resultant mass-loss rates and wind speeds are clearly affected by the choice of stellar temperature, mass, luminosity and the abundance of available carbon. In certain parts of the parameter space there is also an inevitable mass-loss threshold, below which a dust-driven wind is not possible. Contrary to some previous studies, we find a strong dependence on the abundance of free carbon, which turns out to be a critical parameter. Furthermore, we have found that the dust grains that form in the atmosphere may grow too large for the commonly-used small-particle approximation of the dust opacity to be strictly valid. This may have some bearing on the wind properties, although further study of this problem is needed before quantitative conclusions can be drawn.Conclusions. The wind properties show relatively simple dependences on stellar parameters above the mass-loss threshold, while the threshold itself is of a more complicated nature. Hence, we chose not to derive any simplistic mass-loss formula, but rather provide a mass-loss prescription in the form of aeasy-to-use FORTRAN routine. Since this mass-loss routine is based on data coming from an essentially self-consistent model of mass loss, it may therefore serve as a better mass-loss prescription for stellar evolution calculations than empirical formulae. Furthermore, we conclude that there are still some issues that need to be investigated, such as the role of grain-sizes.
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| 30. |
- Mattsson, Lars, 1974-, et al.
(författare)
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Dust Driven Mass Loss from Carbon Stars as Function of Stellar Parameters II : Effects of Relaxing the Small Particle Approximation
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Context. It is well-established that the winds of carbon-rich AGB stars (carbon stars) can be driven by radiation pressure on grains of amorphous carbon and collisional transfer of momentum to the gas. This has been demonstrated by different numerical wind models including time-dependent dust formation, where it has been assumed that the dust grains that form never grow to sizes comparable to wavelengths around the stellar flux maximum (or beyond), which simplifies the treatment of grain opacities considerably. It is not clear, however, if this small particle approximation (SPA) is always valid. Aims. In this paper we explore the effects of relaxing the SPA by considering a few less severe approximations for the radiation pressure efficiency, which include the effects of grain sizes. The purpose of the study is mainly to establish when the SPA can be applied and to quantify the possible errors that may occur when it does not hold. Methods. We have computed wind models with time-dependent dust formation and grain-size dependent opacities, where (1) the radiation pressure efficiency is approximated using grain sizes based on various means of the grain size distribution, and (2) where the problem is simplified by assuming a single dust-grain size. Results. It is shown that in critical cases, the effect of grain sizes can be significant. Mass-loss rates may increase by a factor of two, or more, and wind speeds may be an order of magnitude higher. Furthermore, all models with grain-size dependent opacities that have resultant winds appear to have much lower degrees of dust condensation, compared to corresponding SPA models. Consequently, the "dust-loss rates" are much lower in the new models. However, for well-developed dust-driven winds, where the dust formation has saturated, the effect of grain sizes on the mass-loss rate and wind speed is almost negligible. Conclusions. We conclude that the SPA is, under many circumstances, a reasonable simplification in models of carbon star mass loss. However, critical cases do exist, where especially the effects of momentum transfer due to scattering become significant. It is therefore uncertain whether previous results for winds in the transition regions (between no dust-driven mass loss and well-developed winds) are quantitatively correct. However, we argue that the SPA is a reasonable simplification for strong dust-driven winds. Furthermore, we note that there are other effects (not yet included in the model) than those of grain-size dependent opacities, which may become important in the critical wind regime.
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| 31. |
- Mattsson, Lars, 1974-, et al.
(författare)
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Effects of Carbon-excess dependent Mass Loss and Molecular Opacities on Models of C-star Evolution
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- We present models of stellar evolution for a 2Msun-star of initial metallicity Z = 0.01 (scaled solar), with focus on the carbon-star phase, the effects of increasing carbon excess on mass loss and molecular opacities. We employ a new, state-of-the-art theoretical mass-loss prescription for dust-driven winds, which takes effects of the carbon excess into account and implement a set of composition-dependent molecular opacities, which incorporates the changes due to the evolution of the carbon excess. This work should be regarded as an exploratory and comparative study. The stellar evolution models were computed using the MESA code-package (http://mesa.sourceforge.net), which includes a new fast and efficient code for stellar evolution, but still needs further calibration before quantitative comparisons with observations can be made. We find that the development of the carbon excess is controlling much of the carbon-star evolution. A very pronounced superwind is forming and the termination of the AGB happens soon after the star becomes carbon rich, in fact, after only 4-5 thermal pulses, which is much less than in existing models.
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| 32. |
- Mattsson, Lars, 1974-, et al.
(författare)
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Intense mass loss from C-rich AGB stars at low metallicity?
- 2008
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 484:1, s. L5-L8
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Tidskriftsartikel (refereegranskat)abstract
- We argue that the energy injection of pulsations may be of greater importance to the mass-loss rate of AGB stars than metallicity, and that the mass-loss trend with metallicity is not as simple as sometimes assumed. Using our detailed radiation hydrodynamical models that include dust formation, we illustrate the effects of pulsation energy on wind properties. We find that the mass-loss rate scales with the kinetic energy input by pulsations as long as a dust-saturated wind does not occur, and all other stellar parameters are kept constant. This includes the absolute abundance of condensible carbon (not bound in CO), which is more relevant than keeping the C/O-ratio constant when comparing stars of different metallicity. The pressure and temperature gradients in the atmospheres of stars, become steeper and flatter, respectively, when the metallicity is reduced, while the radius where the atmosphere becomes opaque is typically associated with a higher gas pressure. This effect can be compensated for by adjusting the velocity amplitude of the variable inner boundary (piston), which is used to simulate the effects of pulsation, to obtain models with comparable kinetic-energy input. Hence, it is more relevant to compare models with similar energy-injections than of similar velocity amplitude. Since there is no evidence for weaker pulsations in low-metallicity AGB stars, we conclude that it is unlikely that low-metallicity C-stars have lower mass-loss rates, than their more metal-rich counterparts with similar stellar parameters, as long as they have a comparable amount of condensible carbon.
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| 33. |
- Mattsson, Lars, et al.
(författare)
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Mass loss evolution and the formation of detached shells around TP-AGB stars
- 2007
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 470:1, s. 339-352
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Tidskriftsartikel (refereegranskat)abstract
- Context: The origin of the so called “detached shells” around AGB stars is not fully understood, but two common hypotheses state that these shells form either through the interaction of distinct wind phases or an eruptive mass loss associated with a He-shell flash. We present a model of the formation of detached shells around thermal pulse asymptotic giant branch (TP-AGB) stars, based on detailed modelling of mass loss and stellar evolution, leading to a combination of eruptive mass loss and wind interaction. Aims: The purpose of this paper is first of all to connect stellar evolution with wind and mass loss evolution and demonstrate its consistency with observations, but also to show how thin detached shells around TP-AGB stars can be formed. Previous attempts to link mass loss evolution with the formation of detached shells were based on approximate prescriptions for the mass loss and have not included detailed modelling of the wind formation as we do here. Methods: Using stellar parameters sampled from an evolutionary track for a 2 ~M_ȯ star, we have computed the time evolution of the atmospheric layers and wind acceleration region during a typical thermal pulse with detailed radiation hydrodynamical models including dust formation. Based on these results, we simulate the subsequent circumstellar envelope (CSE) evolution using a spherical hydrodynamic model. Results: We find that existing simple mass loss prescriptions all suggest different mass loss evolutions and that they differ from our detailed wind modelling. The most important factor for the formation of a detached shell is the wind velocity evolution which has a strong impact on the wind interaction and the resulting pile-up of matter. Our CSE model shows that a thin shell structure may be formed as a consequence of a rather short phase of intense mass loss in combination with a significant variation in the wind velocity, as obtained by our wind models. This situation can only be obtained for a limited range of amplitudes for the piston boundary used in the dynamic atmosphere models. Conclusions: The combined mass loss eruption and wind interaction scenario for the formation of detached shells around AGB stars (suggested by previous work) is confirmed by the present modelling. Changes in mass loss rate and wind velocity due to a He-shell flash are adequate for creating distinct wind phases and a “snow plow effect” that is necessary to form a geometrically thin detached shell. The derived properties of the shell (i.e. radius, thickness and density) are more or less consistent with existing observational constraints.
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| 34. |
- Mattsson, Lars, et al.
(författare)
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On the Connection between Mass Loss and Evolution of C-rich AGB Stars
- 2007
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Ingår i: Why Galaxies Care About AGB Stars: Their Importance as Actors and Probes. - 9781583813188 ; , s. 239-243
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The mass-loss properties of carbon rich AGB stars are not very well constrained at present. A variety of empirical or theoretical formulae with different parameterisations are available in the literature and the agreement between them is anything but good. These simple mass-loss prescriptions are nonetheless used in many models of stellar evolution without much consideration of their applicability in various cases. We present here an on-going project aiming at a better description of the mass loss, that could be used to improve stellar evolution models -- especially the evolution during the TP-AGB phase. As a first step, we have considered the mass-loss evolution during a He-shell flash. Using stellar parameters sampled from a stellar evolutionary track, we have computed the time evolution of the atmospheric layers and wind acceleration region during a flash event with detailed frequency-dependent radiation-hydrodynamical models including dust formation. We find that existing simple mass-loss prescriptions imply mass-loss evolutions different than our model. Based on these results, we have also simulated the subsequent long-term dynamical evolution of the circumstellar envelope (CSE), including the formation of a detached shell. The second step of the project deals with the dependence of mass loss on the basic stellar parameters. At the moment we are computing a large grid of wind models for C-rich AGB stars. Preliminary results show that simple parameterisations are difficult to obtain in certain regions of the parameter space considered, due to strong non-linearities in the wind mechanism.
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| 35. |
- Mattsson, Lars, 1974-
(författare)
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On the Winds of Carbon Stars and the Origin of Carbon : A Theoretical Study
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Carbon is the basis for life, as we know it, but its origin is still largely unclear. Carbon-rich Asymptotic Giant Branch (AGB) stars (carbon stars) play an important rôle in the cosmic matter cycle and may contribute most of the carbon in the Galaxy. In this thesis it is explored how the dust-driven mass loss of these stars depends on the basic stellar parameters by computing a large grid of wind models. The existence of a critical wind regime and mass-loss thresholds for dust-driven winds are confirmed. Furthermore, a steep dependence of mass loss on carbon excess is found. Exploratory work on the effects of different stellar metallicities and the sizes of dust grains shows that strong dust-driven winds develop also at moderately low metallicities, and that typical sizes of dust grains affect the wind properties near a mass-loss threshold. It is demonstrated that the mass-loss rates obtained with the wind models have dramatic consequences when used in models of carbon-star evolution. A pronounced superwind develops soon after the star becomes carbon rich, and it therefore experiences only a few thermal pulses as a carbon star before the envelope is lost. The number of dredge-up events and the thermal pulses is limited by a self-regulating mechanism: each thermal pulse dredges up carbon, which increases the carbon excess and hence also the mass-loss rate. In turn, this limits the number of thermal pulses. The mass-loss evolution during a thermal pulse (He-shell flash) is considered as an explanation of the observations of so-called detached shells around carbon stars. By combining models of dust-driven winds with a stellar evolution model, and a simple hydrodynamic model of the circumstellar envelope, it is shown that wind properties change character during a He-shell flash such that a thin detached gas shell can form by wind-wind interaction. Finally, it is suggested that carbon stars are responsible for much of the carbon in the interstellar medium, but a scenario where high-mass stars are major carbon producers cannot be excluded. In either case, however, the carbon abundances of the outer Galactic disc are relatively low, and most of the carbon has been released quite recently. Thus, there may neither be enough carbon, nor enough time, for more advanced carbon-based life to emerge in the outer Galaxy. This lends some support to the idea that only the mid-part of the Galactic disc can be a “Galactic habitable zone”, since the inner parts of the Galaxy are plagued by frequent supernova events that are presumably harmful to all forms of life.
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| 36. |
- Mattsson, L., et al.
(författare)
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Relaxing the Small Particle Approximation for Dust-Grain Opacities in Carbon-star Wind Models
- 2011
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Ingår i: Why Galaxies Care about AGB Stars II.
-
Konferensbidrag (refereegranskat)abstract
- We have computed wind models with time-dependent dust formation and grain-size dependent opacities, where (1) the problem is simplified by assuming a fixed dust-grain size, and where (2) the radiation pressure efficiency is approximated using grain sizes based on various means of the actual grain size distribution. It is shown that in critical cases, the effect of grain sizes can be significant. For well-developed winds, however, the effects on the mass-loss rate and the wind speed are small.
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| 37. |
- Mattsson, Lars, et al.
(författare)
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Thresholds for the Dust Driven Mass Loss from C-rich AGB Stars
- 2007
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Ingår i: Stellar Populations as Building Blocks of Galaxies. ; , s. 37-38
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- It is well established that mass loss from AGB stars due to dust driven winds cannot be arbitrarily low. We model the mass loss from carbon rich AGB stars using detailed frequency-dependent radiation hydrodynamics including dust formation. We present a study of the thresholds for the mass loss rate as a function of stellar parameters based on a subset of a larger grid of such models and compare these results to previous observational and theoretical work. Furthermore, we demonstrate the impact of the pulsation mechanism and dust formation for the creation of a stellar wind and how it affects these thresholds and briefly discuss the consequences for stellar evolution.
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| 38. |
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| 39. |
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| 40. |
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| 41. |
- Mattsson, Susanne, 1978-
(författare)
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Health-related Internet use and screening for emotional distress in people with cancer
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of this thesis was to investigate the preferences and incentives for using Internet-delivered support among people with cancer and to develop and test a generic questionnaire measuring health-related Internet use, the Health Online Support Questionnaire (HOSQ). Another aim was to examine the psychometric properties of the online-administered Hospital Anxiety and Depression Scale (HADS) and Visual Analogue Scale (VAS) regarding anxiety and depression in psychosocial screening among people with cancer, in comparisons with the longer instruments Montgomery Åsberg Depression Rating Scale – Self-report (MADRS-S) and the State Trait Anxiety Inventory – State (STAI-S).Study I was a correlational and descriptive study on the development and psychometric properties of the HOSQ. Study II was a cross-sectional and descriptive study on health related Internet use in patients with cancer. Study III was a cross-sectional and descriptive study examining preferences for psychological treatments. Study IV was a psychometric comparison study of two short instruments and two longer instruments measuring anxiety and depression.Findings from study I showed that the HOSQ might be a reliable and valid instrument for measuring the use of online support for people with health problems. Results ought to be replicated though in larger and other groups to confirm the results for different diagnoses. Findings from study II confirmed results from other studies showing that people with cancer turn to the Internet for informational support that enables them to influence their care and to stay in touch with friends and relatives. Demographical differences regarding the uptake of Internet-based support remains, which indicates a need for research on how to bridge this digital gap. In study III, we found that a large majority preferred psychological treatment face to face whereas Internet-based interventions were reported as the preferred choice by a minority. Findings from the content analysis suggest that Internet-based interventions have specific advantages that may facilitate help-seeking among some individuals and some disadvantages that may be perceived as barriers. Initiatives to increase treatment acceptability may benefit from addressing the advantages and disadvantages reported in this study. In study IV we found that the use of the short and ultrashort tools HADS and VAS identified anxiety and depression in patients with cancer with high accuracy in comparisons with the longer instruments.In conclusion, online screening with the HADS and VAS may be a suitable initial method to identify anxiety and depression in patients with cancer. There is still a large proportion of patients who lack the interest or eHealth literacy to use health-related support on the Internet. By learning more about the barriers, use and perception of eHealth and Internet-based interventions, adequate support may be offered.
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| 42. |
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| 43. |
- Mattsson, Susanne, et al.
(författare)
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Identification of Anxiety and Depression Symptoms in Patients With Cancer : Comparison Between Short and Long Web-Based Questionnaires
- 2019
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Ingår i: Journal of Medical Internet Research. - : JMIR Publications Inc.. - 1438-8871. ; 21:4
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Physicians and nurses in cancer care easily fail to detect symptoms of psychological distress because of barriers such as lack of time, training on screening methods, and knowledge about how to diagnose anxiety and depression. National guidelines in several countries recommend routine screening for emotional distress in patients with cancer, but in many clinics, this is not implemented. By inventing screening methods that are time-efficient, such as digitalized and automatized screenings with short instruments, we can alleviate the burden on patients and staff.OBJECTIVE: The aim of this study was to compare Web-based versions of the ultrashort electronic Visual Analogue Scale (eVAS) anxiety and eVAS depression and the short Hospital Anxiety and Depression Scale (HADS) with Web-based versions of the longer Montgomery Åsberg Depression Rating Scale-Self-report (MADRS-S) and the State Trait Anxiety Inventory- State (STAI-S) with regard to their ability to identify symptoms of anxiety and depression in patients with cancer.METHODS: Data were obtained from a consecutive sample of patients with newly diagnosed (<6 months) breast, prostate, or colorectal cancer or with recurrence of colorectal cancer (N=558). The patients were recruited at 4 hospitals in Sweden between April 2013 and September 2015, as part of an intervention study administered via the internet. All questionnaires were completed on the Web at the baseline assessment in the intervention study.RESULTS: The ultrashort and short Web-based-delivered eVAS anxiety, eVAS depression and HADS were found to have an excellent ability to discriminate between persons with and without clinical levels of symptoms of anxiety and depression compared with recommended cutoffs of the longer instruments MADRS-S and STAI-S (area under the curve: 0.88-0.94). Cutoffs of >6 on HADS anxiety and >7 hundredths (hs) on eVAS anxiety identified patients with anxiety symptoms with high accuracy. For HADS depression, at a cutoff of >5 and eVAS depression at a cutoff of >7 hs, the accuracy was very high likewise.CONCLUSIONS: The use of the short and ultrashort tools, eVAS and HADS, may be a suitable initial method of Web-based screening in busy clinical settings. However, there are still a proportion of patients who lack access to the internet or the ability to use it. There is a need to find solutions for this group to find all the patients with psychological distress.
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| 44. |
- Mattsson, Susanne, et al.
(författare)
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Internet-based stepped care with interactive support and cognitive behavioral therapy for reduction of anxiety and depressive symptoms in cancer : a clinical trial protocol
- 2013
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 13, s. 414-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Approximately 20-30% of patients with cancer experience a clinically relevant level of emotional distress in response to disease and treatment. This in itself is alarming but it is even more problematic because it is often difficult for physicians and nurses to identify cancer patients who experience clinically relevant levels of anxiety and depression symptoms. This can result in persistent distress and can cause human suffering as well as costs for individuals and to the community. Methods: Applying a multi-disciplinary and design-oriented approach aimed at attaining new evidence-based knowledge in basic and applied psychosocial oncology, this protocol will evaluate an intervention to be implemented in clinical practice to reduce cancer patient anxiety and depression. A prospective randomized design will be used. The overarching goal of the intervention is to promote psychosocial health among patients suffering from cancer by means of self-help programmes delivered via an Internet platform. Another goal is to reduce costs for individuals and society, caused by emotional distress in response to cancer. Following screening to detect levels of patient distress, patients will be randomized to standard care or a stepped care intervention. For patients randomized to the intervention, step 1 will consist of self-help material, a chat forum where participants will be able to communicate with each other, and a Frequently Asked Questions (FAQ) section where they can ask questions and get answers from an expert. Patients in the intervention group who still report symptoms of anxiety or depression after access to step 1 will be offered step 2, which will consist of cognitive behavioral therapy (CBT) administered by a personal therapist. The primary end point of the study is patients' levels of anxiety and depression, evaluated longitudinally during and after the intervention. Discussion: There is a lack of controlled studies of the psychological and behavioral processes involved in this type of intervention for anxiety and depressive disorders. Since anxiety and depressive symptoms are relatively common in patients with cancer and the availability of adequate support efforts is limited, there is a need to develop evidence-based stepped care for patients with cancer, to be delivered via the Internet.
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| 45. |
- Mattsson, Susanne, et al.
(författare)
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Measuring Use of Health-Related Support on the Internet : Development of the Health Online Support Questionnaire (HOSQ)
- 2015
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Ingår i: Journal of Medical Internet Research. - : JMIR Publications Inc.. - 1438-8871. ; 17:11
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Tidskriftsartikel (refereegranskat)abstract
- Background: Social support plays an important role for the perceived health in people with health problems and chronic diseases.Provision of different kinds of support during the disease trajectory is crucial for many people. Online support is ubiquitous andrepresents a promising modality for people with chronic diseases. There are no existing instruments that measure various aspectsof online support.Objective: The objective of this study was to create a generic questionnaire regarding health-related support online that can beapplied to people with various health problems and illnesses. Additionally, we wanted to test the questionnaire in a cancerpopulation to assess its adequacy in the context of severe disease.Methods: Initial items for the Health Online Support Questionnaire (HOSQ) were inspired by sociologist James House regardingsocial support. An exploratory factor analysis was conducted in healthy persons or with minor health problems (n=243) on 31initial items. The scale was reduced to 18 items and the internal consistency and reliability of the scale was examined along withcontent validity. Further validation was conducted by a confirmatory analysis on the 18-item scale in a cancer population (n=215).In addition, data on demographics, health problems experienced, and Internet use were collected.Results: The exploratory factor analysis on the final 18-item scale resulted in 2 factors. After scrutinizing the content, thesefactors were labeled “reading” and “interacting” and they demonstrated good internal consistency (Cronbach alphas .88 and .77,respectively). The factors were confirmed in the cancer population. The response pattern revealed expected differences bothbetween the interaction and reading scales and according to age, gender, education, and health problems thereby supporting thevalidity of the HOSQ.Conclusions: The HOSQ may be a reliable and valid instrument for measuring the use of online support for people with healthproblems, but the results ought to be replicated in more studies to confirm the results for different diagnoses. If the results of thisstudy are corroborated by future studies, the HOSQ may be used as a basis for the development of different forms of support onthe Internet.
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| 46. |
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| 47. |
- Mattsson, Susanne, et al.
(författare)
-
Post-separation abuse and women's expriences of quality of life, safety and space for action
- 2023
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Separation from a perpetrator of domestic violence does not necessarily mean that violence and abuse ends. Instead, abuse may continue through different tactics a long time after separation. There is currently a lack of research examining post-separation abuse as a coherent phenomenon in a Swedish context. This project intends to investigate post-separation abuse with different research approaches and from different perspectives. More specifically the project studies subjection to different tactics of post-separation abuse among women, how the post-separation abuse interferes with women's living conditions, physical and psychological health, space for action and safety. Another purpose of the projects is to study women’s experiences of how authorities and agencies respond to post-separation abuse and how women experience the support offered.The project includes a quantitative survey to measure prevalence, correlates and consequences of post-separation abuse, and an interview study exploring women’s experiences of post-separation abuse. Selected results, based on a qualitative content analysis of interviews with twenty women recruited in a Swedish clinical setting for women who has been subjected to IPV, will be presented. The results will highlight women’s experiences of post-separation abuse and its impact on their living conditions, safety, and space for action. The project as a whole will contribute with theoretical knowledge on post-separation abuse, increase the understanding of how perpetrators can use legal rights in different ways to perpetrate continued violence and threats and what the consequences might be for the victims. Through knowledge and conceptualization of the extent, expressions, responses and consequences of post-separation abuse, different tactics can be counteracted and prevented by adequate interventions.
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| 48. |
- Mattsson, Tuve, et al.
(författare)
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Towards a wood based material biorefinery - A demonstrator
- 2015
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Ingår i: 6th Nordic Wood Biorefinery Conference, NWBC 2015. - : VTT Technical Research Centre of Finland. - 9789513883539 ; , s. 92-101
-
Konferensbidrag (refereegranskat)abstract
- Wood, the most abundant ligno-cellulosic raw material available, is a key potential feedstock for production of more sustainable alternatives to fossil-based materials. However advances within the fields of extraction and treatment processes within what is often referred to as the biorefinery concept is essential to allow for such transition. In this study, several different methods for the extraction and separation of wood constituents have been combined in a single process with the purpose of achieving a high overall efficiency of material extraction and utilisation. The work builds on several activities within the Wallenberg Wood Science Center (WWSC). The aim is to present a laboratory-scale demonstrator that illustrates how the different constituents can be separated from the wood matrix for later use in the production of bio-based materials and chemicals. The process steps involved have been tested as integral steps in a linked process for a scale of operations that range from the kilogram-scale down to the gram-scale. Industrially chipped softwood, containing mainly spruce with some pine, was used as raw material.
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| 49. |
- Mattsson-Thorngren, Linnea, et al.
(författare)
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Developing methods for assessing abundance and distribution of European oysters (Ostrea edulis) using towed video
- 2017
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 12:11
-
Tidskriftsartikel (refereegranskat)abstract
- Due to large-scale habitat losses and increasing pressures, benthic habitats in general, and perhaps oyster beds in particular, are commonly in decline and severely threatened on regional and global scales. Appropriate and cost-efficient methods for mapping and monitoring of the distribution, abundance and quality of remaining oyster populations are fundamental for sustainable management and conservation of these habitats and their associated values. Towed video has emerged as a promising method for surveying benthic communities in a both non-destructive and cost-efficient way. Here we examine its use as a tool for quantification and monitoring of oyster populations by (i) analysing how well abundances can be estimated and how living Ostrea edulis individuals can be distinguished from dead ones, (ii) estimating the variability within and among observers as well as the spatial variability at a number of scales, and finally (iii) evaluating the precision of estimated abundances under different scenarios for monitoring. Overall, the results show that the can be used to quantify abundance and occurrence of Ostrea edulis in heterogeneous environments. There was a strong correlation between abundances determined in the field and abundances estimated by video-analyses (r2 = 0.93), even though video analyses underestimated the total abundance of living oysters by 20%. Additionally, the method was largely repeatable within and among observers and revealed no evident bias in identification of living and dead oysters. We also concluded that the spatial variability was an order of magnitude larger than that due to observer errors. Subsequent modelling of precision showed that the total area sampled was the main determinant of precision and provided general method for determining precision. This study provides a thorough validation of the application of towed video on quantitative estimations of live oysters. The results suggest that the method can indeed be very useful for this purpose and we therefor recommend it for future monitoring of oysters and other threatened habitats and species. © 2017 Thorngren et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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| 50. |
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