| 1. |
- Häfner, Sophia J., et al.
(författare)
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Ribosomal RNA 2′-O-methylation dynamics impact cell fate decisions
- 2023
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Ingår i: Developmental Cell. - 1534-5807. ; 58:17, s. 9-1609
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Tidskriftsartikel (refereegranskat)abstract
- Translational regulation impacts both pluripotency maintenance and cell differentiation. To what degree the ribosome exerts control over this process remains unanswered. Accumulating evidence has demonstrated heterogeneity in ribosome composition in various organisms. 2′-O-methylation (2′-O-me) of rRNA represents an important source of heterogeneity, where site-specific alteration of methylation levels can modulate translation. Here, we examine changes in rRNA 2′-O-me during mouse brain development and tri-lineage differentiation of human embryonic stem cells (hESCs). We find distinct alterations between brain regions, as well as clear dynamics during cortex development and germ layer differentiation. We identify a methylation site impacting neuronal differentiation. Modulation of its methylation levels affects ribosome association of the fragile X mental retardation protein (FMRP) and is accompanied by an altered translation of WNT pathway-related mRNAs. Together, these data identify ribosome heterogeneity through rRNA 2′-O-me during early development and differentiation and suggest a direct role for ribosomes in regulating translation during cell fate acquisition.
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| 2. |
- Knudsen, Gitte M, et al.
(författare)
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Guidelines for the content and format of PET brain data in publications and archives : A consensus paper
- 2020
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Ingår i: Journal of Cerebral Blood Flow and Metabolism. - : SAGE Publications. - 0271-678X .- 1559-7016. ; 40:8, s. 1576-1585
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Tidskriftsartikel (refereegranskat)abstract
- It is a growing concern that outcomes of neuroimaging studies often cannot be replicated. To counteract this, the magnetic resonance (MR) neuroimaging community has promoted acquisition standards and created data sharing platforms, based on a consensus on how to organize and share MR neuroimaging data. Here, we take a similar approach to positron emission tomography (PET) data. To facilitate comparison of findings across studies, we first recommend publication standards for tracer characteristics, image acquisition, image preprocessing, and outcome estimation for PET neuroimaging data. The co-authors of this paper, representing more than 25 PET centers worldwide, voted to classify information as mandatory, recommended, or optional. Second, we describe a framework to facilitate data archiving and data sharing within and across centers. Because of the high cost of PET neuroimaging studies, sample sizes tend to be small and relatively few sites worldwide have the required multidisciplinary expertise to properly conduct and analyze PET studies. Data sharing will make it easier to combine datasets from different centers to achieve larger sample sizes and stronger statistical power to test hypotheses. The combining of datasets from different centers may be enhanced by adoption of a common set of best practices in data acquisition and analysis.
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| 3. |
- Bergfelt Lennmyr, Emma, 1984-
(författare)
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Registry-Based Studies in Adult Acute Lymphoblastic Leukemia in Sweden : Survival and Quality of Life
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Acute lymphoblastic leukemia (ALL), a common child malignancy, also constitutes a minor fraction of adult cancer with approximately 50 new cases per year in Sweden. While the five-year overall survival (OS) in pediatric ALL is more than 90%, the prognosis in adults is dismal. Using the Swedish ALL quality registry, this thesis investigates treatment and outcome of adult ALL according to national guidelines. In addition, the introduction of patient-reported outcome in the ALL and Acute Myeloid Leukemia registries is evaluated. In Paper I, measurement of minimal residual disease by flow cytometry was found to be feasible but not consistently applied in the 35 patients with Philadelphia (Ph)-negative B-ALL investigated. In Paper II, treatment, toxicity and outcome of 155 patients, 55-85 years (y) with ALL diagnosis between 2005 and 2012 were studied in detail by patient charts review. An age-adopted protocol recommended from 2009 did not result in better outcome. In Paper III, disease recurrence in the same cohort as Paper II was studied. The median overall survival (OS) after ALL relapse was 3.6 months. In Paper IV, the whole ALL registry was studied and OS was estimated in 930 adult patients diagnosed in the periods 1997-2006 and 2007-2015. Five year OS improved in patients 18-45y from 50% to 65%, in patients 46-65y from 25% to 46%, and in patients >65y from 7% to 11%. This demonstrates that young patients have the best prognosis, in part due to the introduction of a dose-intense “pediatric-like” chemotherapy protocol. Compared to women, middle-aged men were found to have a worse outcome.Historically, Philadelphia-positive (Ph-pos) ALL has a poor prognosis compared to Ph-negative ALL. In this material, the frequency of Ph-pos ALL was 34% of examined B-ALL. Analysis of the whole registry revealed that in 2007-2015, i.e. after the introduction of the tyrosine kinase inhibitor imatinib, Ph-pos ALL was no longer associated with inferior OS. In Paper V, ALL and Acute Myeloid Leukemia patients, six months after diagnosis, completed a web or paper questionnaire regarding quality of life, symptoms and experience with care. The response rate was 64%. Depression symptoms were frequent (18%), especially in young women who reported worrying about fertility.In summary, although OS in adult ALL has improved, more effective and less toxic therapies in upfront treatment are highly warranted. Collection of patient-reported outcome in a national quality registry is feasible and can add important aspects of cancer care that are not usually addressed.
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| 4. |
- Hatemi, Peter, et al.
(författare)
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Genetic Influences on Political Ideologies : Twin Analyses of 19 Measures of Political Ideologies from Five Democraciesand Genome-Wide Findings from Three Populations
- 2014
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Ingår i: Behavior Genetics. - : Springer Science and Business Media LLC. - 0001-8244 .- 1573-3297. ; 44:3, s. 282-294
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Tidskriftsartikel (refereegranskat)abstract
- Almost 40 years ago, evidence from large studies of adult twins and their relatives suggested that between 30 and 60 % of the variance in social and political attitudes could be explained by genetic influences. However, these findings have not been widely accepted or incorporated into the dominant paradigms that explain the etiology of political ideology. This has been attributed in part to measurement and sample limitations, as well the relative absence of molecular genetic studies. Here we present results from original analyses of a combined sample of over 12,000 twins pairs, ascertained from nine different studies conducted in five democracies, sampled over the course of four decades. We provide evidence that genetic factors play a role in the formation of political ideology, regardless of how ideology is measured, the era, or the population sampled. The only exception is a question that explicitly uses the phrase “Left–Right”. We then present results from one of the first genome-wide association studies on political ideology using data from three samples: a 1990 Australian sample involving 6,894 individuals from 3,516 families; a 2008 Australian sample of 1,160 related individuals from 635 families and a 2010 Swedish sample involving 3,334 individuals from 2,607 families. No polymorphisms reached genome-wide significance in the meta-analysis. The combined evidence suggests that political ideology constitutes a fundamental aspect of one’s genetically informed psychological disposition, but as Fisher proposed long ago, genetic influences on complex traits will be composed of thousands of markers of very small effects and it will require extremely large samples to have enough power in order to identify specific polymorphisms related to complex social traits.
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| 5. |
- Jacobsen, Ramune, et al.
(författare)
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Online and Blended Learning Courses for Healthcare Professionals and Policymakers on Patients' Perspectives on Medicine : A Project Report.
- 2022
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Ingår i: Pharmacy. - : MDPI AG. - 2226-4787. ; 10:2
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Tidskriftsartikel (refereegranskat)abstract
- In order for healthcare professionals to better engage with patients, they need to understand and integrate the perspectives of patients into their daily work. In this project, we developed two courses for healthcare professionals on patients' perspectives on medicine. One course was an online course that introduced the patients' perspectives on medicine and explained its importance for healthcare and health policy. The second course was a blended learning course, consisting of online modules and face-to-face webinars, which specified how to explore patients' perspectives in qualitative interviews, and how to develop implementation plans. Patients participated in the development, execution, and evaluation of both courses. Overall, more than 2000 healthcare professionals enrolled in the first course and, in just over a year, 191 participants completed the online course; 57 healthcare professionals registered in the second blended learning course and six participants completed both components of the course. The relevance of knowledge gained was positively evaluated. Participants especially appreciated the participation of patients. Based on the feedback, the second blended learning course was adapted to run online and both courses continue to be freely available to all interested healthcare professionals on the Coursera platform.
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| 6. |
- Jakobsson, Martin, et al.
(författare)
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Arctic Ocean glacial history
- 2014
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Ingår i: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791 .- 1873-457X. ; 92, s. 40-67
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Forskningsöversikt (refereegranskat)abstract
- While there are numerous hypotheses concerning glacial interglacial environmental and climatic regime shifts in the Arctic Ocean, a holistic view on the Northern Hemisphere's late Quaternary ice-sheet extent and their impact on ocean and sea-ice dynamics remains to be established. Here we aim to provide a step in this direction by presenting an overview of Arctic Ocean glacial history, based on the present state-of-the-art knowledge gained from field work and chronological studies, and with a specific focus on ice-sheet extent and environmental conditions during the Last Glacial Maximum (LGM). The maximum Quaternary extension of ice sheets is discussed and compared to LGM. We bring together recent results from the circum-Arctic continental margins and the deep central basin; extent of ice sheets and ice streams bordering the Arctic Ocean as well as evidence for ice shelves extending into the central deep basin. Discrepancies between new results and published LGM ice-sheet reconstructions in the high Arctic are highlighted and outstanding questions are identified. Finally, we address the ability to simulate the Arctic Ocean ice sheet complexes and their dynamics, including ice streams and ice shelves, using presently available ice-sheet models. Our review shows that while we are able to firmly reject some of the earlier hypotheses formulated to describe Arctic Ocean glacial conditions, we still lack information from key areas to compile the holistic Arctic Ocean glacial history.
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| 7. |
- Nors Perdersen, Martin, et al.
(författare)
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Direct Correlation Between Ligand-Induced α-Synuclein Oligomers and Amyloid-like Fibril Growth.
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 5, s. 10422-
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Tidskriftsartikel (refereegranskat)abstract
- Aggregation of proteins into amyloid deposits is the hallmark of several neurodegenerative diseases such as Alzheimer's and Parkinson's disease. The suggestion that intermediate oligomeric species may be cytotoxic has led to intensified investigations of pre-fibrillar oligomers, which are complicated by their transient nature and low population. Here we investigate alpha-synuclein oligomers, enriched by a 2-pyridone molecule (FN075), and the conversion of oligomers into fibrils. As probed by leakage assays, the FN075 induced oligomers potently disrupt vesicles in vitro, suggesting a potential link to disease related degenerative activity. Fibrils formed in the presence and absence of FN075 are indistinguishable on microscopic and macroscopic levels. Using small angle X-ray scattering, we reveal that FN075 induced oligomers are similar, but not identical, to oligomers previously observed during alpha-synuclein fibrillation. Since the levels of FN075 induced oligomers correlate with the amounts of fibrils among different FN075:protein ratios, the oligomers appear to be on-pathway and modeling supports an 'oligomer stacking model' for alpha-synuclein fibril elongation.
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| 8. |
- Nørgaard, Jesper, et al.
(författare)
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Absence of Large-Scale Ice Masses in Central Northeast Siberia During the Late Pleistocene
- 2023
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 50:10
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Tidskriftsartikel (refereegranskat)abstract
- Ongoing speculation regarding the existence of large Late Pleistocene ice masses in Northeast Eurasia reflects the dearth of age constraints on glaciations across this vast region. Here, we report the first dates from the central part of Northeast Siberia, consisting of 22 cosmogenic 10Be exposure ages from boulders deriving from a sequence of three moraines in the Chersky Range. The dated moraine sequence indicates progressive contraction of maximum glacier extent from Marine Isotope Stage 6 to the Last Glacial Maximum, while the remotely-sensed mapping indicates an older, more expansive glaciation in the region yet undated. Our results show that Late Pleistocene glaciations were limited to the highlands, and Northeast Siberia did not host a large, coalescent ice sheet during the Last Glacial Maximum or Marine Isotope Stage 6.
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| 9. |
- Nørgaard, Martin, et al.
(författare)
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Cerebral serotonin transporter measurements with [11C]DASB : A review on acquisition and preprocessing across 21 PET centres
- 2019
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Ingår i: Journal of Cerebral Blood Flow and Metabolism. - 0271-678X .- 1559-7016. ; 39:2, s. 210-222
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Tidskriftsartikel (refereegranskat)abstract
- Positron Emission Tomography (PET) imaging has become a prominent tool to capture the spatiotemporal distribution of neurotransmitters and receptors in the brain. The outcome of a PET study can, however, potentially be obscured by suboptimal and/or inconsistent choices made in complex processing pipelines required to reach a quantitative estimate of radioligand binding. Variations in subject selection, experimental design, data acquisition, preprocessing, and statistical analysis may lead to different outcomes and neurobiological interpretations. We here review the approaches used in 105 original research articles published by 21 different PET centres, using the tracer [11C]DASB for quantification of cerebral serotonin transporter binding, as an exemplary case. We highlight and quantify the impact of the remarkable variety of ways in which researchers are currently conducting their studies, while implicitly expecting generalizable results across research groups. Our review provides evidence that the foundation for a given choice of a preprocessing pipeline seems to be an overlooked aspect in modern PET neuroscience. Furthermore, we believe that a thorough testing of pipeline performance is necessary to produce reproducible research outcomes, avoiding biased results and allowing for better understanding of human brain function.
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| 10. |
- Nørgaard, Thomas, et al.
(författare)
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Animal or plant: which is the better fog water collector?
- 2012
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:4
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Tidskriftsartikel (refereegranskat)abstract
- Occasional fog is a critical water source utilised by plants and animals in the Namib Desert. Fog basking beetles (Onymacris unguicularis, Tenebrionidae) and Namib dune bushman grass (Stipagrostris sabulicola, Poaceae) collect water directly from the fog. While the beetles position themselves optimally for fog water collection on dune ridges, the grass occurs predominantly at the dune base where less fog water is available. Differences in the fog-water collecting abilities in animals and plants have never been addressed. Here we place beetles and grass side-by-side in a fog chamber and measure the amount of water they collect over time. Based on the accumulated amount of water over a two hour period, grass is the better fog collector. However, in contrast to the episodic cascading water run-off from the grass, the beetles obtain water in a steady flow from their elytra. This steady trickle from the beetles' elytra to their mouth could ensure that even short periods of fog basking - while exposed to predators - will yield water. Up to now there is no indication of specialised surface properties on the grass leafs, but the steady run-off from the beetles could point to specific property adaptations of their elytra surface.
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| 11. |
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