| 1. |
- Smedby, Karin Ekström, et al.
(författare)
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Ultraviolet radiation exposure and risk of malignant lymphomas
- 2005
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 0027-8874 .- 1460-2105. ; 97:3, s. 199-209
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The incidence of malignant lymphomas has been increasing rapidly, but the causes of these malignancies remain poorly understood. One hypothesis holds that exposure to ultraviolet (UV) radiation increases lymphoma risk. We tested this hypothesis in a population-based case-control study in Denmark and Sweden. METHODS: A total of 3740 patients diagnosed between October 1, 1999, and August 30, 2002, with incident malignant lymphomas, including non-Hodgkin lymphoma, chronic lymphocytic leukemia, and Hodgkin lymphoma, and 3187 population controls provided detailed information on history of UV exposure and skin cancer and information on other possible risk factors for lymphomas. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by logistic regression. Statistical tests were two-sided. RESULTS: Multivariable-adjusted analyses revealed consistent, statistically significant negative associations between various measures of UV light exposure and risk of non-Hodgkin lymphoma. A high frequency of sun bathing and sunburns at age 20 years and 5-10 years before the interview and sun vacations abroad were associated with 30%-40% reduced risks of non-Hodgkin lymphoma (e.g., for sunbathing four times a week or more at age 20 versus never sunbathing, OR = 0.7, 95% CI = 0.6 to 0.9; for two or more sunburns a year at age 20 versus no sunburns, OR = 0.6, 95% CI = 0.5 to 0.8). These inverse associations increased in strength with increasing levels of exposure (all P(trend)< or =.01). Similar, albeit weaker, associations were observed for Hodgkin lymphoma. There were no clear differences among non-Hodgkin lymphoma subtypes, although associations were stronger for B-cell than for T-cell lymphomas. A history of skin cancer was associated with a doubling in risks of both non-Hodgkin and Hodgkin lymphoma. CONCLUSIONS: A history of high UV exposure was associated with reduced risk of non-Hodgkin lymphoma. The positive association between skin cancer and malignant lymphomas is, therefore, unlikely to be mediated by UV exposure.
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| 2. |
- Tornøe, Birte, et al.
(författare)
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Specific strength training compared with interdisciplinary counseling for girls with tension-type headache : A randomized controlled trial
- 2016
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Ingår i: Journal of Pain Research. - 1178-7090. ; 9, s. 257-270
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Tidskriftsartikel (refereegranskat)abstract
- Background: Childhood tension-type headache (TTH) is a prevalent and debilitating condition for the child and family. Low-cost nonpharmacological treatments are usually the first choice of professionals and parents. This study examined the outcomes of specific strength training for girls with TTH. Methods: Forty-nine girls aged 9–18 years with TTH were randomized to patient education programs with 10 weeks of strength training and compared with those who were counseled by a nurse and physical therapist. Primary outcomes were headache frequency, intensity, and duration; secondary outcomes were neck–shoulder muscle strength, aerobic power, and pericranial tenderness, measured at baseline, after 10 weeks intervention, and at 12 weeks follow-up. Health-related quality of life (HRQOL) questionnaires were assessed at baseline and after 24 months. Results: For both groups, headache frequency decreased significantly, P=0.001, as did duration, P=0.022, with no significant between-group differences. The odds of having headache on a random day decreased over the 22 weeks by 0.65 (0.50–0.84) (odds ratio [95% confidence interval]). For both groups, neck extension strength decreased significantly with a decrease in cervicothoracic extension/flexion ratio to 1.7, indicating a positive change in muscle balance. In the training group, shoulder strength increased ≥10% in 5/20 girls and predicted VO2max increased ≥15% for 4/20 girls. In the training group, 50% of girls with a headache reduction of ≥30% had an increase in VO2max >5%. For the counseling group, this was the case for 29%. A 24-month follow-up on HRQOL for the pooled sample revealed statistically significant improvements. Fifty-five percent of the girls reported little to none disability. Conclusion: The results indicate that both physical health and HRQOL can be influenced significantly by physical exercise and nurse counseling. More research is needed to examine the relationship between physical exercise, VO2max, and TTH in girls. Thus, empowering patient education to promote maximum possible outcomes for all children needs more attention.
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| 3. |
- Allentoft, Morten E., et al.
(författare)
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100 ancient genomes show repeated population turnovers in Neolithic Denmark
- 2024
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Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 625, s. 329-337
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Tidskriftsartikel (refereegranskat)abstract
- Major migration events in Holocene Eurasia have been characterized genetically at broad regional scales1–4. However, insights into the population dynamics in the contact zones are hampered by a lack of ancient genomic data sampled at high spatiotemporal resolution5–7. Here, to address this, we analysed shotgun-sequenced genomes from 100 skeletons spanning 7,300 years of the Mesolithic period, Neolithic period and Early Bronze Age in Denmark and integrated these with proxies for diet (13C and 15N content), mobility (87Sr/86Sr ratio) and vegetation cover (pollen). We observe that Danish Mesolithic individuals of the Maglemose, Kongemose and Ertebølle cultures form a distinct genetic cluster related to other Western European hunter-gatherers. Despite shifts in material culture they displayed genetic homogeneity from around 10,500 to 5,900 calibrated years before present, when Neolithic farmers with Anatolian-derived ancestry arrived. Although the Neolithic transition was delayed by more than a millennium relative to Central Europe, it was very abrupt and resulted in a population turnover with limited genetic contribution from local hunter-gatherers. The succeeding Neolithic population, associated with the Funnel Beaker culture, persisted for only about 1,000 years before immigrants with eastern Steppe-derived ancestry arrived. This second and equally rapid population replacement gave rise to the Single Grave culture with an ancestry profile more similar to present-day Danes. In our multiproxy dataset, these major demographic events are manifested as parallel shifts in genotype, phenotype, diet and land use.
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| 4. |
- Allentoft, Morten E., et al.
(författare)
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Population genomics of post-glacial western Eurasia
- 2024
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Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 625:7994, s. 301-311
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Tidskriftsartikel (refereegranskat)abstract
- Western Eurasia witnessed several large-scale human migrations during the Holocene1–5. Here, to investigate the cross-continental effects of these migrations, we shotgun-sequenced 317 genomes—mainly from the Mesolithic and Neolithic periods—from across northern and western Eurasia. These were imputed alongside published data to obtain diploid genotypes from more than 1,600 ancient humans. Our analyses revealed a ‘great divide’ genomic boundary extending from the Black Sea to the Baltic. Mesolithic hunter-gatherers were highly genetically differentiated east and west of this zone, and the effect of the neolithization was equally disparate. Large-scale ancestry shifts occurred in the west as farming was introduced, including near-total replacement of hunter-gatherers in many areas, whereas no substantial ancestry shifts happened east of the zone during the same period. Similarly, relatedness decreased in the west from the Neolithic transition onwards, whereas, east of the Urals, relatedness remained high until around 4,000 bp, consistent with the persistence of localized groups of hunter-gatherers. The boundary dissolved when Yamnaya-related ancestry spread across western Eurasia around 5,000 bp, resulting in a second major turnover that reached most parts of Europe within a 1,000-year span. The genetic origin and fate of the Yamnaya have remained elusive, but we show that hunter-gatherers from the Middle Don region contributed ancestry to them. Yamnaya groups later admixed with individuals associated with the Globular Amphora culture before expanding into Europe. Similar turnovers occurred in western Siberia, where we report new genomic data from a ‘Neolithic steppe’ cline spanning the Siberian forest steppe to Lake Baikal. These prehistoric migrations had profound and lasting effects on the genetic diversity of Eurasian populations.
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| 5. |
- Almers, Ellen
(författare)
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Handlingskompetens för hållbar utveckling : Tre berättelser om vägen dit
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Studiens mål är att bidra till kunskapsutveckling om hur unga människor utvecklar handlingskompetens för hållbar utveckling. Med handlingskompetens för hållbar utveckling avses i studien vilja och förmåga att påverka livsstil och levnadsvillkor på ett sätt sominkluderar intergenerationellt och globalt ansvar. I avhandlingen introduceras begreppet avståndsmoral för att beskriva detta ansvar, som utsträcker sig i både tid och rum, till kommande generationer och till nu levande människor globalt. En utgångspunkt för studien är att hållbar utveckling innefattar idén om avståndsmoraliskt ansvar. Studiens huvudfråga är: Hur erfar avståndsmoraliskt aktivt handlande unga människor att de utvecklat handlingskompetens för hållbar utveckling?Studiens teorigrund är livsvärldsfenomenologisk. En upplevd verklighet undersöks i studien via berättelser. Genom ett strategiskt urval har tre intervjupersoner, som motiverar sina handlingar med avståndsmoraliska argument, valts att ingå i studien. Datainsamlingen har skett genom en kombination av öppna livsberättelseintervjuer ochhalvstrukturerade intervjuer. Analys och tolkning har metodologiskt stöd i berättelseforskningstraditionen och empirisk fenomenologisk forskning.Resultaten presenteras som tre citatrika levnadsberättelser om Karin, Carl och Matilda, tre unga vuxna med flera års engagemang i hållbarhetsfrågor. Syftet med levnadsberättelserna är att bidra till förståelse av det speciella i en enskild individs upplevelse av attutveckla handlingskompetens för hållbar utveckling. En integrerande analys redovisar mönster i form av likheter och skillnader mellan de tre individernas berättelser om att utveckla olika aspekter av handlingskompetens i avståndsmoraliska frågor. Sex gemensammakärnpoänger framstår som betydelsefulla: känslomässiga reaktioner, upplevd kompetens, kontrasterande perspektiv och normativ grund, handlingsimpregnering, tillit från och tillit till vuxna samt social gemenskap kontra utanförskap. Som motiv och drivkrafterför engagemanget framstår känslomässiga reaktioner som initierar önskan om förändring och vilja till handling, längtan efter meningsfullhet, önskan om att komma till sin rätt och längtan efter gemenskap. Resultaten diskuteras i förhållande till tidigare forskningoch en modell av en möjlig väg att utveckla aspekter av handlingskompetens för hållbar utveckling presenteras. Diskussionskapitlet utmynnar i fyra didaktiska utmaningar för enutbildning för hållbar utveckling.
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| 6. |
- Armerin, Fredrik, 1971-
(författare)
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Aspects of cash-flow valuation
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis consists of five papers. In the first two papers we consider a general approach to cash flow valuation, focusing on dynamic properties of the value of a stream of cash flows. The third paper discusses immunization theory, where old results are shown to hold in general deterministic models, but often fail to be true in stochastic models. In the fourth paper we comment on the connection between arbitrage opportunities and an immunized position. Finally, in the last paper we study coherent and convex measure of risk applied to portfolio optimization and insurance.
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| 7. |
- Armerin, Fredrik, et al.
(författare)
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Term Structure Models with Parallel and Proportional Shifts
- 2007
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Ingår i: Applied Mathematical Finance. - : Informa UK Limited. - 1350-486X .- 1433-4313 .- 1466-4313. ; 14:3, s. 243-260
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the possibility of an arbitrage free model for the term structure of in-terest rates where the yield curve only changes through a parallel shift. We consider HJMtype forward rate models driven by a multidimensional Wiener process as well as by a gen-eral marked point process. Within this general framework we show that there does indeedexist a large variety of nontrivial parallel shift term structure models, and we also describethese in detail. We also show that there exists no nontrivial flat term structure model. Thesame analysis is repeated for the similar case, where the yield curve only changes throughproportional shifts.
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| 8. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 9. |
- Ericsson, Maria, 1982-
(författare)
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Stress in chickens : Effects of domestication and early experience on behaviour and welfare
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The domestication is the process where animals have adapted to human conditions. A prerequisite for domestication is tame behaviour towards humans and subsequently, selection for other desirable traits took place which led to changes in several behavioural and physiological parameters. The domestication of chickens (Gallus gallus) was initiated around 8000 years ago, and today we see clear phenotypic and genotypic alterations when comparing domestic breeds with the wild ancestor. Our modern domestic production breeds have been selected for, and still undergo heavy selection for high meat and egg yields. Beside obvious morphological changes, studies investigating behavioural differences between the ancestral Red Junglefowl and domestic breeds show, for example, differences in fearfulness, foraging strategies, exploratory behaviour and sociality. The modern production environments are intense and already from hatch chicks are exposed to harsh conditions. From an animal welfare perspective, the production environment contain many stressful aspects. The shift in stressor types between wild and captive conditions have likely contributed to alterations in stress tolerance when comparing domestic breeds to the wild ancestors. Previous research on mammalian models have underlined that early-life stressor exposure can induce negative consequences both immediately and in adulthood, but can also affect the offspring in a transgenerational fashion. The effects observed are for example disturbance of normal brain development, a hyper-reactive hypothalamic-pituitary-adrenal (HPA) -axis, decreased immune function and increased risk of developing cognitive dysfunction and abnormal behaviour. In chickens, the long-term effects of stress during the chick phase and during puberty are not well-investigated, and further, conflicting data has been presented on the hatchling HPA-axis reactivity.In this thesis, results from four projects are presented, which all concern stress and welfare at different ages in chickens. The development of the HPA-axis and how chicks respond to early stress both on the short- and long term was investigated. Furthermore, an experiment on the effects of stress exposure a different ages during puberty was conducted, in search of particularly stress-sensitive periods. Two papers address domestication effects on the stress response.In paper I, the results show that the HPA-axis is fully functioning at hatch, resulting in elevated corticosterone levels at exposure to stressful conditions. Breed differences indicate domestication effects on the reactivity and development of the HPA-axis; the Red Junglefowl displayed a lower corticosterone baseline and a lower stress response on day one, compared to a domestic breed, whereas the results were the opposite on day 23. Similar results were seen in paper IV, conducted on adult birds, where the Red Junglefowl had a more pronounced reaction to acute stress but a faster recovery period, both with respect to behaviour and physiology. In commercial hatcheries, chick are exposed to multiple potential stressors on their first day of life. In paper II, chicks who had experienced the potentially stressful environment in a commercial hatchery was compared to a quietly treated control group. The hatchery managed birds displayed a reduced growth pattern and tendencies towards altered vigilance and reduced locomotion was seen as an effect of stress in adulthood.In paper III, it was demonstrated that one week of stress exposure at different ages during the chick phase and puberty affect long-term behaviour and physiology, however depending on age of stress exposure, different parameters were affected. The early stress also induced transgenerational effects, most clearly on HPA-axis reactivity, and showed some overlapping differentially expressed genes.In summary, domestication has altered the acute stress coping behaviours as well as the development and reactivity of the HPA-axis both in young and adult birds. Furthermore, puberty can be regarded as an equally stress sensitive period as the chick stage and affect various behaviours, stress physiology and gene expression. The outcome can vary depending on timing and nature of stressor.
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| 10. |
- Hansen, Bjarne R. S., et al.
(författare)
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Hydrogen Storage Capacity Loss in a LiBH4-Al Composite
- 2013
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Ingår i: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 117:15, s. 7423-7432
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Tidskriftsartikel (refereegranskat)abstract
- A detailed investigation of the decomposition reactions and decay in the hydrogen storage capacity during repeated hydrogen release and uptake cycles for the reactive composite LiBH4-Al (2:3) is presented. Furthermore, the influence of a titanium boride, TiB2, additive is investigated. The study combines information from multiple techniques: in situ synchrotron radiation powder X-ray diffraction, Sieverts measurements, simultaneous thermogravimetric analysis, differential scanning calorimetry and mass spectroscopy, solid-state magic-angle spinning nuclear magnetic resonance (MAS NMR), and Raman spectroscopy. The decomposition of LiBH4-Al results in the formation of LiAl, AlB2, and Li2B12H12 via several reactions and intermediate compounds. The TiB2 additive appears to have a limited effect on the decomposition pathway of the samples, but seems to facilitate formation of intermediate species at lower temperatures compared to the sample without additive. Solid solutions of LixAl1-xB2 or Al1-xB2 are observed during decomposition and from Rietveld refinement the composition of the solid solution is estimated to be Li0.22Al0.78B2. The intercalation of Li in the AlB2 structure is further investigated by B-11 and Al-27 MAS NMR spectra of the LiH-AlB2 and AlB2 samples (presented in Supporting Information). Hydrogen release and uptake for LiBH4-Al reveals a significant loss in the hydrogen storage capacity, that is, after four cycles a capacity of about 45% remains, and after 10 cycles, the capacity is degraded to approximately 15% of the theoretically available hydrogen content. This capacity loss may be due to the formation of Li2B12H12, as observed by B-11 MAS NMR and Raman spectroscopy. Formation of Li2B12H12 has previously been observed during the decomposition of LiBH4, but it has not been reported earlier in the LiBH4-Al (2:3) system.
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| 11. |
- Hønge, Bo L., et al.
(författare)
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T-cell and B-cell perturbations are similar in ART-naive HIV-1 and HIV-1/2 dually infected patients
- 2019
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Ingår i: AIDS. - 0269-9370. ; 33:7, s. 1143-1153
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: HIV-2 may slow progression of a subsequently acquired HIV-1 infection through cross-neutralizing antibodies and polyfunctional CD8 T cells. We hypothesized that HIV-1/2 dually infected patients compared with HIV-1-infected patients had more preserved immune maturation subsets and less immune activation of T and B cells. METHODS: ART-naive patients with HIV-1 (n = 83) or HIV-1/2 dual (n = 27) infections were included in this cross-sectional study at an HIV clinic in Guinea-Bissau. Peripheral blood mononuclear cells (PBMCs) were analyzed by flow cytometry according to T-cell maturation and activation, regulatory T-cell fraction, and B-cell maturation and activation. RESULTS: HIV-1/2 dually infected patients had lower levels of HIV-1 RNA compared with patients with HIV-1 infection, but the levels of total HIV RNA (HIV-1 and HIV-2) were similar in the two patient groups. T-cell maturation, and proportions of regulatory T cells (FoxP3+) were also similar in the two groups. HIV-1/2 dually infected patients had higher proportions of CD4 and CD8 T cells positive for the activation marker CD38, but there was no difference in other T-cell activation markers (CD28, CTLA-4, PD-1). HIV-1/2 dually infected patients also had higher proportions of IgM-only B cells and plasmablasts. CONCLUSION: HIV-1/2 was not associated with less immune perturbations than for HIV-1 infection.
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| 12. |
- Jensen, Claus L., et al.
(författare)
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Revision Total Knee Arthroplasty With the Use of Trabecular Metal Cones A Randomized Radiostereometric Analysis With 2 Years of Follow-Up
- 2012
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Ingår i: Journal of Arthroplasty. - : Elsevier BV. - 0883-5403. ; 27:10, s. 1820-1826
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Tidskriftsartikel (refereegranskat)abstract
- "Trabecular Metal Cone" (TM Cone) (Zimmer, Inc, Warsaw, Ind) for reconstruction of bone loss in the proximal tibia during revision total knee arthroplasty is now optional. Forty patients were randomized to receive revision total knee arthroplasty with or without TM Cone (No TM Cone). The Anderson Orthopaedic Research Institute bone loss classification and NexGen revision system were used. Radiostereometric analysis was performed with 24 months of follow-up. Maximum total point motion: stable migration was seen in the TM Cone group. No statistically significant difference was found. Segment motion analysis at 24 months showed the same net direction of rotation for the groups around the y-, z-axis and around the x-, y-axis for translation. Tibial revision implants with TM Cone result in an early stable situation with less irregular migration pattern than revision without TM Cone.
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| 13. |
- Madsen, Bjarne K, et al.
(författare)
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Efficacy of strength training on tension-type headache : A randomised controlled study
- 2018
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Ingår i: Cephalalgia. - : SAGE Publications. - 0333-1024 .- 1468-2982. ; 38:6, s. 1071-1080
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Tidskriftsartikel (refereegranskat)abstract
- Background Strength training has shown effects in reducing neck pain. As neck pain is highly prevalent in tension-type headache (TTH), it is relevant to examine the effect of strength training of the shoulder muscles on TTH patients. Aim To examine the effect of strength training of the shoulder/neck muscles on TTH frequency and duration. Methods Sixty patients with TTH were randomised into strength training or a control group. The strength training group trained ten weeks with elastic resistance bands. The control group performed ergonomic and posture correction. Efficacy was evaluated at follow-up after 19-22 weeks. Results Twenty-three patients completed strength training and 21 completed ergonomic and posture correction (per-protocol). No between-group effect was detected, but within groups numerical reductions were noted in both groups from baseline to follow-up. Frequency of TTH in the strength training group decreased by 11% ( P = 0.041) and duration decreased by10% ( P = 0.036), while the ergonomic and posture correction group showed a significant reduction in frequency of 24% ( P = 0.0033) and a decrease in duration of 27% ( P = 0.041). Conclusion No significant difference between the groups was found and the within-group effects did not reach clinical significance. Combining all the elements into a multifaceted intervention could prove more useful and should be further explored in future studies. Clinical trials registration number NCT02984826.
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| 14. |
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| 15. |
- Mittelmark, Maurice, et al.
(författare)
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Salutogenesis as a system approach to health promotion
- 2011
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Ingår i: Health promotion at the system level.
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Konferensbidrag (refereegranskat)abstract
- An ongoing systematic analysis of the global evidence on the overall impact and effectiveness of a salutogenic approach to health promotion proves that people and systems that develop the ability to implement a salutogenic approch strenghening the Sense of Coherence, will create systems where people not only live longer but perceive they are in good health, enjoy a better quality of life and mental wellbeing. In addition, they can withstand stress better than the average and are inclined to more constructive health behaviours. Even if they become acutely ill or develop a chronic disease such as an NCD they will manage better than the average. Overall the approach responds positively as a system to the acation areas and policies of the Ottawa Charter.Reference: The Hitchhikers Guide to Salutogenesis, Folkhälsan Research Report 2, 2010 The IUHPE Global Working Group on Salutogenesis formed a core group of 10 research centers in December 2010. Here the Nordic Representatives covering 4 Nordic Countries will speak to the issue healthy public policy implications, mental health and quality of life, health behaviours, chronic disease (NCDs), healthy learning and empowerment, community action. Further describing how the contemporary evidence is collected, documented and analyzed.Authors: Prof. Maurice Mittelmark, HEMIL Senter, NO, Prof. Geir A. Espnes, NTNU, NO, Prof. Bjarne Bruune Jensen, STENO Center, DK, Prof. Mima Cattan, Folkhälsan, FI, Dr Monica Eriksson, University West, Sweden, Prof. Bengt Lindström, Folkhälsan, FI.
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| 16. |
- Nguyen, Quynh T., et al.
(författare)
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Seasonal variation of atmospheric particle number concentrations, new particle formation and atmospheric oxidation capacity at the high Arctic site Villum Research Station, Station Nord
- 2016
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 16:17, s. 11319-11336
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Tidskriftsartikel (refereegranskat)abstract
- This work presents an analysis of the physical properties of sub-micrometer aerosol particles measured at the high Arctic site Villum Research Station, Station Nord (VRS), northeast Greenland, between July 2010 and February 2013. The study focuses on particle number concentrations, particle number size distributions and the occurrence of new particle formation (NPF) events and their seasonality in the high Arctic, where observations and characterization of such aerosol particle properties and corresponding events are rare and understanding of related processes is lacking. A clear accumulation mode was observed during the darker months from October until mid-May, which became considerably more pronounced during the prominent Arctic haze months from March to mid-May. In contrast, nucleation- and Aitken-mode particles were predominantly observed during the summer months. Analysis of wind direction and wind speed indicated possible contributions of marine sources from the easterly side of the station to the observed summertime particle number concentrations, while southwesterly to westerly winds dominated during the darker months. NPF events lasting from hours to days were mostly observed from June until August, with fewer events observed during the months with less sunlight, i.e., March, April, September and October. The results tend to indicate that ozone (O3) might be weakly anti-correlated with particle number concentrations of the nucleation-mode range (10-30ĝ€nm) in almost half of the NPF events, while no positive correlation was observed. Calculations of air mass back trajectories using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model for the NPF event days suggested that the onset or interruption of events could possibly be explained by changes in air mass origin. A map of event occurrence probability was computed, indicating that southerly air masses from over the Greenland Sea were more likely linked to those events.
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| 17. |
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| 18. |
- Rysgaard, Søren, et al.
(författare)
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A mobile observatory powered by sun and wind for near real time measurements of atmospheric, glacial, terrestrial, limnic and coastal oceanic conditions in remote off-grid areas
- 2022
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Ingår i: HardwareX. - : Elsevier BV. - 2468-0672. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is rapidly altering the Arctic environment. Although long-term environmental observations have been made at a few locations in the Arctic, the incomplete coverage from ground stations is a main limitation to observations in these remote areas. Here we present a wind and sun powered multi-purpose mobile observatory (ARC-MO) that enables near real time measurements of air, ice, land, rivers, and marine parameters in remote off-grid areas. Two test units were constructed and placed in Northeast Greenland where they have collected data from cabled and wireless instruments deployed in the environment since late summer 2021. The two units can communicate locally via WiFi (units placed 25 km apart) and transmit near-real time data globally over satellite. Data are streamed live and accessible from (https://gios.org). The cost of one mobile observatory unit is c. 304.000€. These test units demonstrate the possibility for integrative and automated environmental data collection in remote coastal areas and could serve as models for a proposed global observatory system.
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| 19. |
- Sund, Per, 1958-
(författare)
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Att urskilja selektiva traditioner i miljöundervisningens socialisationsinnehåll - implikationer för undervisning för hållbar utveckling
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Discerning selective traditions in the socialization content of environmental education – implications for education for sustainable developmentThis thesis offers an empirical contribution to research on content issues in environmental education. One way of approaching content issues is to study the socialization content. Socialization content forms an educational context in which subject matter content can develop into meaning. Through their different actions teachers communicate companion meanings to students, which together constitute the socialization content. These are messages about the subject and about education, such as the importance of students’ participation.One important starting point for this thesis is that the learning of subject matter and socialization content is simultaneous. Learning is often regarded as an inner individual process, while socialization is more often understood as an external fostering. By using the concept of meaning making, learning and socialization can be regarded as both simultaneous and mutual.The thesis has two main purposes, namely, methodological development and a more substantial study of socialization content. An interview method and analytical tool for researchers has been developed as a result of conducting a literature review and interviewing upper secondary school teachers involved in a general science course. This tool can be used to study the qualitative aspects of socialization content by examining shifts in five important educational aspects, and has been applied to the empirical data collected from teacher and student interviews.The analytical tool can also be transformed into a reflection tool for teachers to render their educational habits more visible. Teachers’ collective habits can develop into selective traditions in environmental education. Socialization content can be regarded as an important value-laden content that needs to be critically examined in an open democratic school system. These discussions could facilitate the development of a more pluralistic environmental education, which in turn could be further developed into an education for sustainable development.
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