| 1. |
- Chapman, Henry N, et al.
(författare)
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Femtosecond X-ray protein nanocrystallography.
- 2011
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 470:7332, s. 73-7
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Tidskriftsartikel (refereegranskat)abstract
- X-ray crystallography provides the vast majority of macromolecular structures, but the success of the method relies on growing crystals of sufficient size. In conventional measurements, the necessary increase in X-ray dose to record data from crystals that are too small leads to extensive damage before a diffraction signal can be recorded. It is particularly challenging to obtain large, well-diffracting crystals of membrane proteins, for which fewer than 300 unique structures have been determined despite their importance in all living cells. Here we present a method for structure determination where single-crystal X-ray diffraction 'snapshots' are collected from a fully hydrated stream of nanocrystals using femtosecond pulses from a hard-X-ray free-electron laser, the Linac Coherent Light Source. We prove this concept with nanocrystals of photosystem I, one of the largest membrane protein complexes. More than 3,000,000 diffraction patterns were collected in this study, and a three-dimensional data set was assembled from individual photosystem I nanocrystals (∼200nm to 2μm in size). We mitigate the problem of radiation damage in crystallography by using pulses briefer than the timescale of most damage processes. This offers a new approach to structure determination of macromolecules that do not yield crystals of sufficient size for studies using conventional radiation sources or are particularly sensitive to radiation damage.
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| 2. |
- Kjær, Kurt H., et al.
(författare)
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A 2-million-year-old ecosystem in Greenland uncovered by environmental DNA
- 2022
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Ingår i: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 612:7939, s. 283-291
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Tidskriftsartikel (refereegranskat)abstract
- Late Pliocene and Early Pleistocene epochs 3.6 to 0.8 million years ago1 had climates resembling those forecasted under future warming2. Palaeoclimatic records show strong polar amplification with mean annual temperatures of 11–19 °C above contemporary values3,4. The biological communities inhabiting the Arctic during this time remain poorly known because fossils are rare5. Here we report an ancient environmental DNA6 (eDNA) record describing the rich plant and animal assemblages of the Kap København Formation in North Greenland, dated to around two million years ago. The record shows an open boreal forest ecosystem with mixed vegetation of poplar, birch and thuja trees, as well as a variety of Arctic and boreal shrubs and herbs, many of which had not previously been detected at the site from macrofossil and pollen records. The DNA record confirms the presence of hare and mitochondrial DNA from animals including mastodons, reindeer, rodents and geese, all ancestral to their present-day and late Pleistocene relatives. The presence of marine species including horseshoe crab and green algae support a warmer climate than today. The reconstructed ecosystem has no modern analogue. The survival of such ancient eDNA probably relates to its binding to mineral surfaces. Our findings open new areas of genetic research, demonstrating that it is possible to track the ecology and evolution of biological communities from two million years ago using ancient eDNA.
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| 3. |
- Abbott, Benjamin W., et al.
(författare)
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Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire : an expert assessment
- 2016
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%-85% of permafrost carbon release can still be avoided if human emissions are actively reduced.
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| 4. |
- Andresen, Louise C., 1974, et al.
(författare)
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Shifting Impacts of Climate Change: Long-Term Patterns of Plant Response to Elevated CO2, Drought, and Warming Across Ecosystems
- 2016
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Ingår i: Large-Scale Ecology: Model Systems to Global Perspectives. - : Elsevier. - 9780081009352 ; , s. 437-473
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Bokkapitel (refereegranskat)abstract
- Field experiments that expose terrestrial ecosystems to climate change factors by manipulations are expensive to maintain, and typically only last a few years. Plant biomass is commonly used to assess responses to climate treatments and to predict climate change impacts. However, response to the treatments might be considerably different between the early years and a decade later. The aim of this data analysis was to develop and apply a method for evaluating changes in plant biomass responses through time, in order to provide a firm basis for discussing how the ‘short-term’ response might differ from the ‘long-term’ response. Across 22 sites situated in the northern hemisphere, which covered three continents, and multiple ecosystems (grasslands, shrublands, moorlands, forests, and deserts), we evaluated biomass datasets from long-term experiments with exposure to elevated CO2 (eCO2), warming, or drought. We developed methods for assessing biomass response patterns to the manipulations using polynomial and linear (piecewise) model analysis and linked the responses to sitespecific variables such as temperature and rainfall. Polynomial patterns across sites indicated changes in response direction over time under eCO2, warming, and drought. In addition, five distinct pattern types were confirmed within sites: ‘no response’, ‘delayed response’, ‘directional response’, ‘dampening response’, and ‘altered response’ patterns. We found that biomass response direction was as likely to change over time as it was to be consistent, and therefore suggest that climate manipulation experiments should be carried out over timescales covering both short- and long-term responses, in order to realistically assess future impacts of climate change.
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| 5. |
- Baun, Michael, et al.
(författare)
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Pharmacological characterization and expression of VIP and PACAP receptors in isolated cranial arteries of the rat
- 2011
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Ingår i: European Journal of Pharmacology. - : Elsevier BV. - 1879-0712 .- 0014-2999. ; 670:1, s. 186-194
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Tidskriftsartikel (refereegranskat)abstract
- Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating peptide (PACAP) are potent vasodilators in animals and humans. PACAP infusion but not VIP infusion precipitates migraine attacks in migraine patients. The vascular effects of VIP and the two varieties of PACAP (PACAP-27 and PACAP-38) were investigated versus selective antagonists in segments of rat middle cerebral arteries (MCA), basilar arteries (BA) and middle meningeal arteries (MMA) using myographs. The luminal and abluminal effects of VIP were studied using perfusion myograph. mRNA expression of the relevant receptors (VPAC(1), VPAC(2) and PAC(1)) was examined by in situ hybridization. There was no significant difference in relaxant potency of the peptides in the MCA. In BA the relaxant potency was VIP>PACAP-27 = PACAP-38. Relaxant responses were either absent or very weak in MMA. VIP was found to be somewhat more potent in BA than in the MCA. Maxadilan, a selective PAC(1)-receptor agonist, showed no relaxant effect in either vessel. The VPAC(2)-antagonist PG 99-465 alone proved ineffective in the MCA, while it had a weak effect on BA. The VPAC(1)-antagonist PG 97269 inhibited relaxation induced by both VIP and the PACAPs in cerebral vessels. In combination, the two antagonists demonstrated better effect than either alone. VIP applied luminally via perfusion myograph caused no dilatation, indicating lack of endothelial involvement. In situ hybridization demonstrated the presence of mRNA for all three receptors in the smooth muscle cells of the vessels. In conclusion, migraine-like headache induced by PACAP-38 infusion is unlikely to be caused by direct vasodilator action on intracranial vessels. (C) 2011 Elsevier B.V. All rights reserved.
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| 6. |
- Bentham, James, et al.
(författare)
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A century of trends in adult human height
- 2016
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Ingår i: eLIFE. - 2050-084X. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.522.7) and 16.5 cm (13.319.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries.
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| 7. |
- Bentham, James, et al.
(författare)
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A century of trends in adult human height
- 2016
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Ingår i: eLIFE. - : eLife Sciences Publications Ltd. - 2050-084X. ; 5
-
Tidskriftsartikel (refereegranskat)abstract
- Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5–22.7) and 16.5 cm (13.3– 19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8– 144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries.
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| 8. |
- Björkman, Ingeborg, et al.
(författare)
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Developing the role of the drug and therapeutics committees : Perceptions of chairs
- 2007
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Ingår i: International Journal of Health Care Quality Assurance. - : Emerald. - 0952-6862. ; 20:2, s. 161-178
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Tidskriftsartikel (refereegranskat)abstract
- Purpose – According to Swedish law, every county is required to have a local drug and therapeutics committee (DTC) to contribute to safe and cost-effective drug use. The law presents merely a framework and gives no detailed instructions addressing, for example, organisation and methods. The aim of this study is to explore the variation of conceptions of the role of the DTCs among committee Chairs and to compare the results with an earlier study. Design/methodology/approach – Data were collected by questionnaires and telephone interviews with committee chairs, which were analysed using a phenomenographic approach. Findings – Four conceptions were identified, namely: traditional, patient-aware, influential, holistic and cooperative, which all involved prescribers. In one conception the DTC acted as an expert to decision-makers. One conception included the notion that cooperation across the bureaucratic borders was important. Patients were involved in two conceptions. Comparison with the earlier study showed a trend toward higher patient awareness and a higher agreement on DTC goals with an increased focus on quality issues. Originality/value – This study demonstrates an alternative research method bringing in new perspectives when exploring activities within healthcare. Patient involvement in the work of the DTCs is increasing, but should be further explored and developed.
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| 9. |
- Björkman, Ingeborg, et al.
(författare)
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The role of drug and therapeutics committees : Perceptions of chairs and information officers
- 2005
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Ingår i: International Journal of Health Care Quality Assurance. - : Emerald. - 0952-6862. ; 18:4, s. 235-48
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Tidskriftsartikel (refereegranskat)abstract
- Purpose – Improved quality and safety in drug use is a public health goal of major importance. In Sweden, local drug and therapeutics committees (DTCs) have adopted the task of working for safe and rational drug use. This study aimed to explore how chairs conceived the role of the DTCs, to explore how information officers conceived their own role, and to determine whether the respondents included patients in their answers. Design/methodology/approach – Data were collected using questionnaires and the answers were analysed according to phenomenographic method to identify conceptions. “Patient awareness” was studied by content analysis. Findings – In both groups the prescribers were the focus of attention, and only a few respondents mentioned patients. A variation of four conceptions was found among chairs and three among information officers. It would be beneficial if DTCs used this knowledge in their development. Originality/value – The importance of “patient awareness” within DTCs must be further explored.
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| 10. |
- Cornelissen, Johannes H C, et al.
(författare)
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Global negative vegetation feedback to climate warming responses of leaf litter decomposition rates in cold biomes
- 2007
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 10:7, s. 619-627
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Tidskriftsartikel (refereegranskat)abstract
- Whether climate change will turn cold biomes from large long-term carbon sinks into sources is hotly debated because of the great potential for ecosystem-mediated feedbacks to global climate. Critical are the direction, magnitude and generality of climate responses of plant litter decomposition. Here, we present the first quantitative analysis of the major climate-change-related drivers of litter decomposition rates in cold northern biomes worldwide.Leaf litters collected from the predominant species in 33 global change manipulation experiments in circum-arctic-alpine ecosystems were incubated simultaneously in two contrasting arctic life zones. We demonstrate that longer-term, large-scale changes to leaf litter decomposition will be driven primarily by both direct warming effects and concomitant shifts in plant growth form composition, with a much smaller role for changes in litter quality within species. Specifically, the ongoing warming-induced expansion of shrubs with recalcitrant leaf litter across cold biomes would constitute a negative feedback to global warming. Depending on the strength of other (previously reported) positive feedbacks of shrub expansion on soil carbon turnover, this may partly counteract direct warming enhancement of litter decomposition.
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| 11. |
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| 12. |
- Djukic, Ika, et al.
(författare)
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Early stage litter decomposition across biomes
- 2018
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 628, s. 1369-1394
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Tidskriftsartikel (refereegranskat)abstract
- Through litter decomposition enormous amounts of carbon is emitted to the atmosphere. Numerous large-scale decomposition experiments have been conducted focusing on this fundamental soil process in order to understand the controls on the terrestrial carbon transfer to the atmosphere. However, previous studies were mostly based on site-specific litter and methodologies, adding major uncertainty to syntheses, comparisons and meta-analyses across different experiments and sites. In the TeaComposition initiative, the potential litter decomposition is investigated by using standardized substrates (Rooibos and Green tea) for comparison of litter mass loss at 336 sites (ranging from −9 to +26 °C MAT and from 60 to 3113 mm MAP) across different ecosystems. In this study we tested the effect of climate (temperature and moisture), litter type and land-use on early stage decomposition (3 months) across nine biomes. We show that litter quality was the predominant controlling factor in early stage litter decomposition, which explained about 65% of the variability in litter decomposition at a global scale. The effect of climate, on the other hand, was not litter specific and explained <0.5% of the variation for Green tea and 5% for Rooibos tea, and was of significance only under unfavorable decomposition conditions (i.e. xeric versus mesic environments). When the data were aggregated at the biome scale, climate played a significant role on decomposition of both litter types (explaining 64% of the variation for Green tea and 72% for Rooibos tea). No significant effect of land-use on early stage litter decomposition was noted within the temperate biome. Our results indicate that multiple drivers are affecting early stage litter mass loss with litter quality being dominant. In order to be able to quantify the relative importance of the different drivers over time, long-term studies combined with experimental trials are needed.
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| 13. |
- Do, Ron, et al.
(författare)
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Common variants associated with plasma triglycerides and risk for coronary artery disease
- 2013
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 45:11, s. 1345-
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Tidskriftsartikel (refereegranskat)abstract
- Triglycerides are transported in plasma by specific triglyceride-rich lipoproteins; in epidemiological studies, increased triglyceride levels correlate with higher risk for coronary artery disease (CAD). However, it is unclear whether this association reflects causal processes. We used 185 common variants recently mapped for plasma lipids (P < 5 x 10(-8) for each) to examine the role of triglycerides in risk for CAD. First, we highlight loci associated with both low-density lipoprotein cholesterol (LDL-C) and triglyceride levels, and we show that the direction and magnitude of the associations with both traits are factors in determining CAD risk. Second, we consider loci with only a strong association with triglycerides and show that these loci are also associated with CAD. Finally, in a model accounting for effects on LDL-C and/or high-density lipoprotein cholesterol (HDL-C) levels, the strength of a polymorphism's effect on triglyceride levels is correlated with the magnitude of its effect on CAD risk. These results suggest that triglyceride-rich lipoproteins causally influence risk for CAD.
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| 14. |
- Ekeberg, Tomas, et al.
(författare)
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Single-shot diffraction data from the Mimivirus particle using an X-ray free-electron laser
- 2016
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Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Free-electron lasers (FEL) hold the potential to revolutionize structural biology by producing X-ray pules short enough to outrun radiation damage, thus allowing imaging of biological samples without the limitation from radiation damage. Thus, a major part of the scientific case for the first FELs was three-dimensional (3D) reconstruction of non-crystalline biological objects. In a recent publication we demonstrated the first 3D reconstruction of a biological object from an X-ray FEL using this technique. The sample was the giant Mimivirus, which is one of the largest known viruses with a diameter of 450 nm. Here we present the dataset used for this successful reconstruction. Data-analysis methods for single-particle imaging at FELs are undergoing heavy development but data collection relies on very limited time available through a highly competitive proposal process. This dataset provides experimental data to the entire community and could boost algorithm development and provide a benchmark dataset for new algorithms.
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| 15. |
- Ekeberg, Tomas, 1983-, et al.
(författare)
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Three-dimensional structure determination with an X-ray laser
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Three-dimensional structure determination of a non-crystalline virus has been achieved from a set of randomly oriented continuous diffraction patterns captured with an X-ray laser. Intense, ultra-short X-ray pulses intercepted a beam of single mimivirus particles, producing single particle X-ray diffraction patterns that are assembled into a three-dimensional amplitude distribution based on statistical consistency. Phases are directly retrieved from the assembled Fourier distribution to synthesize a three-dimensional image. The resulting electron density reveals a pseudo-icosahedral asymmetric virion structure with a compartmentalized interior, within which the DNA genome occupies only about a fifth of the volume enclosed by the capsid. Additional electron microscopy data indicate the genome has a chromatin-like fiber structure that has not previously been observed in a virus.
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| 16. |
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| 17. |
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| 18. |
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| 19. |
- Heděnec, Petr, et al.
(författare)
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Mycorrhizal association of common European tree species shapes biomass and metabolic activity of bacterial and fungal communities in soil
- 2020
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Ingår i: Soil Biology and Biochemistry. - : Elsevier BV. - 0038-0717. ; 149
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies have revealed effects of various tree species on soil physical and chemical properties. However, effects of various tree species on composition and activity of soil microbiota and the relevant controls remain poorly understood. We evaluated the influence of tree species associated with two different mycorrhizal types, ectomycorrhiza (EcM) and arbuscular mycorrhiza (AM), on growth, biomass and metabolic activity of soil fungal and bacterial communities using common garden tree species experiments throughout Denmark. The soil microbial communities differed between six European tree species as well as between EcM (beech, lime, oak and spruce) and AM (ash and maple) tree species. The EcM tree species had higher fungal biomass, fungal growth and bacterial biomass, while AM species showed higher bacterial growth. The results indicated that microbial community composition and functioning differed between groups of tree species with distinct litter qualities that generate soil C/N ratio and soil pH differences. The mycorrhizal association only partly explained litter quality and soil microbial species differences since lime was more similar to AM tree species. In addition, our results indicated that tree species-mediated soil pH and C/N ratio were the most important variables shaping microbial communities with a positive effect on bacterial and a negative effect on fungal growth rates. The results suggest that tree species-mediated microbial community composition and activity may be important drivers of the different vertical soil C distribution previously observed in AM and EcM tree species.
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| 20. |
- Heděnec, Petr, et al.
(författare)
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Tree species traits and mycorrhizal association shape soil microbial communities via litter quality and species mediated soil properties
- 2023
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127. ; 527
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Tidskriftsartikel (refereegranskat)abstract
- Soils harbor a vast diversity of soil microbiota, which play a crucial role in key ecosystem processes such as litter transformation and mineralization, but how complex plant-soil interactions shape the diversity and composition of soil microbiota remains elusive. We performed amplicon sequencing of DNA isolated from mineral topsoil of six common European trees planted in multi-site common garden monoculture stands of broadleaved maple and ash associated with arbuscular mycorrhiza (AM), broadleaved beech, lime and oak associated with ectomycorrhizal fungi (ECM) and coniferous spruce associated with ECM. The main aim of this study was to evaluate the effects of tree species identity, traits and mycorrhizal associations on diversity, community structure, cohesion, and shift in the relative abundance of taxonomic and functional groups of soil bacteria, fungi and nematodes. Our results revealed that soils beneath broadleaved trees hosted higher OTU richness of bacteria, fungi, and nematodes than under Norway spruce. Broadleaved tree species associated with AM fungi showed higher cohesion of bacterial and fungal communities than broadleaved trees associated with ECM fungi, but the cohesion of nematode communities was higher under trees associated with ECM fungi than under trees associated with AM fungi. Copiotrophic bacteria, fungal saprotrophs and bacterivorous nematodes were associated with ash, maple and lime having high soil pH, and high litter decomposition indices, while oligotrophic bacteria, ectomycorrhizal fungi and fungivorous nematodes were associated with beech, oak and Norway spruce that had low soil pH and low litter decomposition indices. Tree species associated with AM fungi had a high proportion of copiotrophic bacteria and saprotrophic fungi while trees associated with ECM fungi showed a high relative abundance of oligotrophic bacteria, ECM fungi and fungivorous nematodes. The different abundances of these functional groups support the more inorganic nutrient economy of AM tree species vs the more organic dominated nutrient economy of ECM tree species. The bacterial community was indirectly affected by litter quality via soil properties, while the fungal community was directly affected by litter quality and tree species. The functional groups of nematodes mirrored the communities of bacteria and fungi, thereby indicating the main and active groups of the tree species-specific microbial communities. Our study suggested that tree species identity, traits, and mycorrhizal association substantially shape microbial communities via a direct effect of litter chemistry as well as via litter-mediated soil properties.
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| 21. |
- Holmstrup, Martin, et al.
(författare)
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Long-term and realistic global change manipulations had low impact on diversity of soil biota in temperate heathland
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- In a dry heathland ecosystem we manipulated temperature (warming), precipitation (drought) and atmospheric concentration of CO2 in a full-factorial experiment in order to investigate changes in below-ground biodiversity as a result of future climate change. We investigated the responses in community diversity of nematodes, enchytraeids, collembolans and oribatid mites at two and eight years of manipulations. We used a structural equation modelling (SEM) approach analyzing the three manipulations, soil moisture and temperature, and seven soil biological and chemical ariables. The analysis revealed a persistent and positive effect of elevated CO2 on litter C:N ratio. After two years of treatment, the fungi to bacteria ratio was increased by warming, and the diversities within oribatid mites, collembolans and nematode groups were all affected by elevated CO2 mediated through increased litter C:N ratio. After eight years of treatment, however, the CO2-increased litter C:N ratio did not influence the diversity in any of the four fauna groups. The number of significant correlations between treatments, food source quality, and soil biota diversities was reduced from six to three after two and eight years, respectively. These results suggest a remarkable resilience within the soil biota against global climate change treatments in the long term.
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| 22. |
- Ismaili, Elgerta, et al.
(författare)
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Fourth consensus of the International Society for Premenstrual Disorders (ISPMD) : auditable standards for diagnosis and management of premenstrual disorder
- 2016
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Ingår i: Archives of Women's Mental Health. - : Springer Science and Business Media LLC. - 1434-1816 .- 1435-1102. ; 19:6, s. 953-958
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Tidskriftsartikel (refereegranskat)abstract
- Whilst professional bodies such as the Royal College and the American College of Obstetricians and Gynecologists have well-established standards for audit of management for most gynaecology disorders, such standards for premenstrual disorders (PMDs) have yet to be developed. The International Society of Premenstrual Disorders (ISPMD) has already published three consensus papers on PMDs covering areas that include definition, classification/quantification, clinical trial design and management (American College Obstetricians and Gynecologists 2011; Brown et al. in Cochrane Database Syst Rev 2:CD001396, 2009; Dickerson et al. in Am Fam Physician 67(8):1743-1752, 2003). In this fourth consensus of ISPMD, we aim to create a set of auditable standards for the clinical management of PMDs. All members of the original ISPMD consensus group were invited to submit one or more auditable standards to be eligible in the inclusion of the consensus. Ninety-five percent of members (18/19) responded with at least one auditable standard. A total of 66 auditable standards were received, which were returned to all group members who then ranked the standards in order of priority, before the results were collated. Proposed standards related to the diagnosis of PMDs identified the importance of obtaining an accurate history, that a symptom diary should be kept for 2 months prior to diagnosis and that symptom reporting demonstrates symptoms in the premenstrual phase of the menstrual cycle and relieved by menstruation. Regarding treatment, the most important standards were the use of selective serotonin reuptake inhibitors (SSRIs) as a first line treatment, an evidence-based approach to treatment and that SSRI side effects are properly explained to patients. A set of comprehensive standards to be used in the diagnosis and treatment of PMD has been established, for which PMD management can be audited against for standardised and improved care.
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| 23. |
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| 24. |
- Kaltsouni, Elisavet, et al.
(författare)
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Electroencephalography findings in menstrually-related mood disorders : A critical review
- 2024
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Ingår i: Frontiers in Neuroendocrinology. - : Elsevier. - 0091-3022 .- 1095-6808. ; 72
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Forskningsöversikt (refereegranskat)abstract
- The female reproductive years are characterized by fluctuations in ovarian hormones across the menstrual cycle, which have the potential to modulate neurophysiological and behavioral dynamics. Menstrually-related mood disorders (MRMDs) comprise cognitive-affective or somatic symptoms that are thought to be triggered by the rapid fluctuations in ovarian hormones in the luteal phase of the menstrual cycle. MRMDs include premenstrual syndrome (PMS), premenstrual dysphoric disorder (PMDD), and premenstrual exacerbation (PME) of other psychiatric disorders. Electroencephalography (EEG) non-invasively records in vivo synchronous activity from populations of neurons with high temporal resolution. The present overview sought to systematically review the current state of task-related and resting-state EEG investigations on MRMDs. Preliminary evidence indicates lower alpha asymmetry at rest being associated with MRMDs, while one study points to the effect being lutealphase specific. Moreover, higher luteal spontaneous frontal brain activity (slow/fast wave ratio as measured by the delta/beta power ratio) has been observed in persons with MRMDs, while sleep architecture results point to potential circadian rhythm disturbances. In this review, we discuss the quality of study designs as well as future perspectives and challenges of supplementing the diagnostic and scientific toolbox for MRMDs with EEG.
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| 25. |
- Locke, Adam E, et al.
(författare)
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Genetic studies of body mass index yield new insights for obesity biology.
- 2015
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 518:7538, s. 197-401
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Tidskriftsartikel (refereegranskat)abstract
- Obesity is heritable and predisposes to many diseases. To understand the genetic basis of obesity better, here we conduct a genome-wide association study and Metabochip meta-analysis of body mass index (BMI), a measure commonly used to define obesity and assess adiposity, in up to 339,224 individuals. This analysis identifies 97 BMI-associated loci (P < 5 × 10(-8)), 56 of which are novel. Five loci demonstrate clear evidence of several independent association signals, and many loci have significant effects on other metabolic phenotypes. The 97 loci account for ∼2.7% of BMI variation, and genome-wide estimates suggest that common variation accounts for >20% of BMI variation. Pathway analyses provide strong support for a role of the central nervous system in obesity susceptibility and implicate new genes and pathways, including those related to synaptic function, glutamate signalling, insulin secretion/action, energy metabolism, lipid biology and adipogenesis.
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| 26. |
- Malavelle, Florent F., et al.
(författare)
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Strong constraints on aerosol-cloud interactions from volcanic eruptions
- 2017
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 546:7659, s. 485-491
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Tidskriftsartikel (refereegranskat)abstract
- Aerosols have a potentially large effect on climate, particularly through their interactions with clouds, but the magnitude of this effect is highly uncertain. Large volcanic eruptions produce sulfur dioxide, which in turn produces aerosols; these eruptions thus represent a natural experiment through which to quantify aerosol-cloud interactions. Here we show that the massive 2014-2015 fissure eruption in Holuhraun, Iceland, reduced the size of liquid cloud droplets-consistent with expectations-but had no discernible effect on other cloud properties. The reduction in droplet size led to cloud brightening and global-mean radiative forcing of around -0.2 watts per square metre for September to October 2014. Changes in cloud amount or cloud liquid water path, however, were undetectable, indicating that these indirect effects, and cloud systems in general, are well buffered against aerosol changes. This result will reduce uncertainties in future climate projections, because we are now able to reject results from climate models with an excessive liquid-water-path response.
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| 27. |
- Maschler, Julia, et al.
(författare)
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Links across ecological scales: Plant biomass responses to elevated CO2
- 2022
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 28:21, s. 6115-6134
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Tidskriftsartikel (refereegranskat)abstract
- The degree to which elevated CO2 concentrations (e[CO2]) increase the amount of carbon (C) assimilated by vegetation plays a key role in climate change. However, due to the short-term nature of CO2 enrichment experiments and the lack of reconciliation between different ecological scales, the effect of e[CO2] on plant biomass stocks remains a major uncertainty in future climate projections. Here, we review the effect of e[CO2] on plant biomass across multiple levels of ecological organization, scaling from physiological responses to changes in population-, community-, ecosystem-, and global-scale dynamics. We find that evidence for a sustained biomass response to e[CO2] varies across ecological scales, leading to diverging conclusions about the responses of individuals, populations, communities, and ecosystems. While the distinct focus of every scale reveals new mechanisms driving biomass accumulation under e[CO2], none of them provides a full picture of all relevant processes. For example, while physiological evidence suggests a possible long-term basis for increased biomass accumulation under e[CO2] through sustained photosynthetic stimulation, population-scale evidence indicates that a possible e[CO2]-induced increase n mortality rates might potentially outweigh the effect of increases in plant growth rates on biomass levels. Evidence at the global scale may indicate that e[CO2] has contributed to increased biomass cover over recent decades, but due to the difficulty to disentangle the effect of e[CO2] from a variety of climatic and land-use-related drivers of plant biomass stocks, it remains unclear whether nutrient limitations or other ecological mechanisms operating at finer scales will dampen the e[CO2] effect over time. By exploring these discrepancies, we identify key research gaps in our understanding of the effect of e[CO2] on plant biomass and highlight the need to integrate knowledge across scales of ecological organization so that large-scale modeling can represent the finer-scale mechanisms needed to constrain our understanding of future terrestrial C storage.
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| 28. |
- Matta, Michèle, et al.
(författare)
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Dietary intake of trans fatty acids and breast cancer risk in 9 European countries
- 2021
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Ingår i: BMC Medicine. - : Springer Science and Business Media LLC. - 1741-7015. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Trans fatty acids (TFAs) have been hypothesised to influence breast cancer risk. However, relatively few prospective studies have examined this relationship, and well-powered analyses according to hormone receptor-defined molecular subtypes, menopausal status, and body size have rarely been conducted. Methods: In the European Prospective Investigation into Cancer and Nutrition (EPIC), we investigated the associations between dietary intakes of TFAs (industrial trans fatty acids [ITFAs] and ruminant trans fatty acids [RTFAs]) and breast cancer risk among 318,607 women. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models, adjusted for other breast cancer risk factors. Results: After a median follow-up of 8.1 years, 13,241 breast cancer cases occurred. In the multivariable-adjusted model, higher total ITFA intake was associated with elevated breast cancer risk (HR for highest vs lowest quintile, 1.14, 95% CI 1.06–1.23; P trend = 0.001). A similar positive association was found between intake of elaidic acid, the predominant ITFA, and breast cancer risk (HR for highest vs lowest quintile, 1.14, 95% CI 1.06–1.23; P trend = 0.001). Intake of total RTFAs was also associated with higher breast cancer risk (HR for highest vs lowest quintile, 1.09, 95% CI 1.01–1.17; P trend = 0.015). For individual RTFAs, we found positive associations with breast cancer risk for dietary intakes of two strongly correlated fatty acids (Spearman correlation r = 0.77), conjugated linoleic acid (HR for highest vs lowest quintile, 1.11, 95% CI 1.03–1.20; P trend = 0.001) and palmitelaidic acid (HR for highest vs lowest quintile, 1.08, 95% CI 1.01–1.16; P trend = 0.028). Similar associations were found for total ITFAs and RTFAs with breast cancer risk according to menopausal status, body mass index, and breast cancer subtypes. Conclusions: These results support the hypothesis that higher dietary intakes of ITFAs, in particular elaidic acid, are associated with elevated breast cancer risk. Due to the high correlation between conjugated linoleic acid and palmitelaidic acid, we were unable to disentangle the positive associations found for these fatty acids with breast cancer risk. Further mechanistic studies are needed to identify biological pathways that may underlie these associations.
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| 29. |
- Nevatte, Tracy, et al.
(författare)
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ISPMD consensus on the management of premenstrual disorders
- 2013
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Ingår i: Archives of Women's Mental Health. - : Springer Science and Business Media LLC. - 1434-1816 .- 1435-1102. ; 16:4, s. 279-291
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Tidskriftsartikel (refereegranskat)abstract
- The second consensus meeting of the International Society for Premenstrual Disorders (ISPMD) took place in London during March 2011. The primary goal was to evaluate the published evidence and consider the expert opinions of the ISPMD members to reach a consensus on advice for the management of premenstrual disorders. Gynaecologists, psychiatrists, psychologists and pharmacologists each formally presented the evidence within their area of expertise; this was followed by an in-depth discussion leading to consensus recommendations. This article provides a comprehensive review of the outcomes from the meeting. The group discussed and agreed that careful diagnosis based on the recommendations and classification derived from the first ISPMD consensus conference is essential and should underlie the appropriate management strategy. Options for the management of premenstrual disorders fall under two broad categories, (a) those influencing central nervous activity, particularly the modulation of the neurotransmitter serotonin and (b) those that suppress ovulation. Psychotropic medication, such as selective serotonin reuptake inhibitors, probably acts by dampening the influence of sex steroids on the brain. Oral contraceptives, gonadotropin-releasing hormone agonists, danazol and estradiol all most likely function by ovulation suppression. The role of oophorectomy was also considered in this respect. Alternative therapies are also addressed, with, e.g. cognitive behavioural therapy, calcium supplements and Vitex agnus castus warranting further exploration.
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| 30. |
- Nielsen, Jonas B., et al.
(författare)
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Genome-wide Study of Atrial Fibrillation Identifies Seven Risk Loci and Highlights Biological Pathways and Regulatory Elements Involved in Cardiac Development
- 2018
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Ingår i: American Journal of Human Genetics. - : Elsevier BV. - 0002-9297 .- 1537-6605. ; 102:1, s. 103-115
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Tidskriftsartikel (refereegranskat)abstract
- Atrial fibrillation (AF) is a common cardiac arrhythmia and a major risk factor for stroke, heart failure, and premature death. The pathogenesis of AF remains poorly understood, which contributes to the current lack of highly effective treatments. To understand the genetic variation and biology underlying AF, we undertook a genome-wide association study (GWAS) of 6,337 AF individuals and 61,607 AF-free individuals from Norway, including replication in an additional 30,679 AF individuals and 278,895 AF-free individuals. Through genotyping and dense imputation mapping from whole-genome sequencing, we tested almost nine million genetic variants across the genome and identified seven risk loci, including two novel loci. One novel locus (lead single-nucleotide variant [SNV] rs12614435; p = 6.76 × 10−18) comprised intronic and several highly correlated missense variants situated in the I-, A-, and M-bands of titin, which is the largest protein in humans and responsible for the passive elasticity of heart and skeletal muscle. The other novel locus (lead SNV rs56202902; p = 1.54 × 10−11) covered a large, gene-dense chromosome 1 region that has previously been linked to cardiac conduction. Pathway and functional enrichment analyses suggested that many AF-associated genetic variants act through a mechanism of impaired muscle cell differentiation and tissue formation during fetal heart development.
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| 31. |
- Pilotto, Francesca, et al.
(författare)
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Meta-analysis of multidecadal biodiversity trends in Europe
- 2020
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Local biodiversity trends over time are likely to be decoupled from global trends, as local processes may compensate or counteract global change. We analyze 161 long-term biological time series (15-91 years) collected across Europe, using a comprehensive dataset comprising ~6,200 marine, freshwater and terrestrial taxa. We test whether (i) local long-term biodiversity trends are consistent among biogeoregions, realms and taxonomic groups, and (ii) changes in biodiversity correlate with regional climate and local conditions. Our results reveal that local trends of abundance, richness and diversity differ among biogeoregions, realms and taxonomic groups, demonstrating that biodiversity changes at local scale are often complex and cannot be easily generalized. However, we find increases in richness and abundance with increasing temperature and naturalness as well as a clear spatial pattern in changes in community composition (i.e. temporal taxonomic turnover) in most biogeoregions of Northern and Eastern Europe. The global biodiversity decline might conceal complex local and group-specific trends. Here the authors report a quantitative synthesis of longterm biodiversity trends across Europe, showing how, despite overall increase in biodiversity metric and stability in abundance, trends differ between regions, ecosystem types, and taxa.
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| 32. |
- Rothwell, Joseph A., et al.
(författare)
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Metabolic signatures of healthy lifestyle patterns and colorectal cancer risk in a European cohort
- 2022
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Ingår i: Clinical Gastroenterology and Hepatology. - : Elsevier. - 1542-3565 .- 1542-7714. ; 20:5, s. e1061-e1082
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Colorectal cancer risk can be lowered by adherence to the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) guidelines. We derived metabolic signatures of adherence to these guidelines and tested their associations with colorectal cancer risk in the European Prospective Investigation into Cancer and Nutrition cohort.Methods: Scores reflecting adherence to the WCRF/AICR recommendations (scale, 1–5) were calculated from participant data on weight maintenance, physical activity, diet, and alcohol among a discovery set of 5738 cancer-free European Prospective Investigation into Cancer and Nutrition participants with metabolomics data. Partial least-squares regression was used to derive fatty acid and endogenous metabolite signatures of the WCRF/AICR score in this group. In an independent set of 1608 colorectal cancer cases and matched controls, odds ratios (ORs) and 95% CIs were calculated for colorectal cancer risk per unit increase in WCRF/AICR score and per the corresponding change in metabolic signatures using multivariable conditional logistic regression.Results: Higher WCRF/AICR scores were characterized by metabolic signatures of increased odd-chain fatty acids, serine, glycine, and specific phosphatidylcholines. Signatures were inversely associated more strongly with colorectal cancer risk (fatty acids: OR, 0.51 per unit increase; 95% CI, 0.29–0.90; endogenous metabolites: OR, 0.62 per unit change; 95% CI, 0.50–0.78) than the WCRF/AICR score (OR, 0.93 per unit change; 95% CI, 0.86–1.00) overall. Signature associations were stronger in male compared with female participants.Conclusions: Metabolite profiles reflecting adherence to WCRF/AICR guidelines and additional lifestyle or biological risk factors were associated with colorectal cancer. Measuring a specific panel of metabolites representative of a healthy or unhealthy lifestyle may identify strata of the population at higher risk of colorectal cancer.
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| 33. |
- Rydhmer, Klas, et al.
(författare)
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Photonic sensors reflect variation in insect abundance and diversity across habitats
- 2024
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Ingår i: Ecological Indicators. - 1470-160X. ; 158
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Tidskriftsartikel (refereegranskat)abstract
- To mitigate ongoing insect biodiversity declines, there is a need for efficient yet accurate monitoring methods. The use of traditional catch-based survey methods is constrained both by costs and need for expertise for manual taxonomic identification. Emerging methods, such as eDNA and robotic sorting, have the potential to reduce workload but still require resource-intensive sample collection in the field. Recently, remote sensing methods such as photonic sensors have shown promise for recording large numbers of insect observations. However, accurately determining species composition in collected data remains a challenge. In this study, we investigated the potential of photonic sensors for quantifying species richness of flying insects in the field and at five sites and compared the results with estimates based on conventional Malaise traps. Firstly, we evaluated two unsupervised clustering methods using a library of measured insect signals from 42 known species. Secondly, we correlated estimated number of clusters in data recorded at five sites with species richness assessment of catches from Malaise traps. This study is based on 84,770 library- and 238,584 field individual insect recordings. Our results demonstrate that both clustering methods perform well and reflect estimates obtained by Malaise traps, indicating the potential of automated insect biodiversity monitoring. This offers the possibility of more efficient but still accurate methods for studying insect biodiversity with broader temporal and spatial coverage.
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| 34. |
- Rydhmer, Klas, et al.
(författare)
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Scheimpflug lidar range profiling of bee activity patterns and spatial distributions
- 2022
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Ingår i: Animal Biotelemetry. - : Springer Science and Business Media LLC. - 2050-3385. ; 10:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Recent declines of honeybees and simplifications of wild bee communities, at least partly attributed to changes of agricultural landscapes, have worried both the public and the scientific community. To understand how wild and managed bees respond to landscape structure it is essential to investigate their spatial use of foraging habitats. However, such studies are challenging since the foraging behaviour of bees differs between species and can be highly dynamic. Consequently, the necessary data collection is laborious using conventional methods and there is a need for novel methods that allow for automated and continuous monitoring of bees. In this work, we deployed an entomological lidar in a homogenous white clover seed crop and profiled the activity of honeybees and other ambient insects in relation to a cluster of beehives. Results: In total, 566,609 insect observations were recorded by the lidar. The total measured range distribution was separated into three groups, out of which two were centered around the beehives and considered to be honeybees, while the remaining group was considered to be wild insects. The validity of this model in separating honeybees from wild insects was verified by the average wing modulation frequency spectra in the dominating range interval for each group. The temporal variation in measured activity of the assumed honeybee observations was well correlated with honeybee activity indirectly estimated using hive scales as well as directly observed using transect counts. Additional insight regarding the three-dimensional distribution of bees close to the hive was provided by alternating the beam between two heights, revealing a “funnel like” distribution around the beehives, widening with height. Conclusions: We demonstrate how lidar can record very high numbers of insects during a short time period. In this work, a spatial model, derived from the detection limit of the lidar and two Gaussian distributions of honeybees centered around their hives was sufficient to reproduce the observations of honeybees and background insects. This methodology can in the future provide valuable new information on how external factors influence pollination services and foraging habitat selection and range of both managed bees and wild pollinators.
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| 35. |
- Sarneel, Judith M., et al.
(författare)
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Reading tea leaves worldwide : decoupled drivers of initial litter decomposition mass-loss rate and stabilization
- 2024
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Ingår i: Ecology Letters. - : John Wiley & Sons. - 1461-023X .- 1461-0248. ; 27:5
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Tidskriftsartikel (refereegranskat)abstract
- The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.
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| 36. |
- Schmidt, Catarina, et al.
(författare)
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”Att vara mellan språken” Studiehandledning för nyanlända elever Rapport från Språkcentrum, Göteborgs stad
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Föreliggande rapport handlar om den studiehandledning som riktas till nyanlända elever på högstadiet och gymnasiets språkintroduktion. De resultat som redovisas utgår från en studie där intervjuer med elever respektive lärare, studiehandledare och rektorer genomförts under 2018. Analysen av dessa intervjuer tar avstamp i forskning kring flerspråkiga hänsynstaganden tillsammans med tillgänglig nationell policy och visar på flera viktiga utvecklingsområden: a) att kartläggning genomförs på ett dialogiskt sätt med berörda elever, lärare och studiehandledare b) att studiehandledning tar avstamp i dokumenterad och fortsatt kartläggning och c) integreras med övrig undervisning. För att studiehandledning ska bli meningsfull och stötta eleven på ett effektivt sätt, krävs pedagogisk delgivning och samverkan mellan studiehandledare och berörda ämneslärare. Studiens resultat belyser rektors tydliga ansvar, när det gäller att leda verksamheten, så att dessa utvecklingsområden kan förbättras. Bortom utvecklingsområden och rutiner för dokumentation visar rapporten på det stora behovet av integration mellan nyanlända och andra jämnåriga elever på skolan och i närområdet. Det handlar om integration för att komma in i språket och för att känna sig välkommen i och delaktig i samhället.
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| 37. |
- Schmidt, Caroline, 1966, et al.
(författare)
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How can the variability in ultrasound measurement of intima-media thickness be reduced? Studies of inteobserver variability in carotid and femoral arteries.
- 1999
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Ingår i: Clinical Physiology. ; 19:1, s. 45-55
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Tidskriftsartikel (refereegranskat)abstract
- A critical component in scientific studies of most biological variables is the variation or error in measurements which leads to non-identical results of repeated measurements from the same subject. The aim of this study was to investigate whether the interobserver error (s) in measurement of intima-media thickness (IMT) in carotid and femoral arteries could be decreased if the mean value obtained using two ultrasound images from each of the right and left arteries was used in the analyses instead of the mean value obtained using images from only the right artery. In addition, we wished to evaluate two different reading procedures, one based on manual tracing of echo interfaces and the other on automated edge detection. In a methodological study, 50 subjects were examined with ultrasound twice in the same day by two independent laboratory technologists. The ultrasound images were analysed in two ways: using a computerized manual tracing analysing system and an automated analysing system. When both right and left carotid arteries were examined (manual reading), the interobserver error was smaller than that determined for the examination of only the right artery, for IMTmean in both the common carotid artery (P = 0·06) and the carotid artery bulb (P<0·05). The interobserver error was also significantly smaller for double-sided vs. one-sided examination with automated reading of IMTmean in the common carotid artery (P<0·01) and in the carotid artery bulb (P<0·01). The coefficient of variation (CV) for measurement in the common carotid artery decreased from 8·6% (one-sided, manual reading) to 5·3% (double-sided, automated reading). The interobserver error in measurement of IMT in the common femoral artery did not improve by examination of both right and left arteries. The results from this study show that the interobserver errors in measurement of IMT can be decreased by using ultrasound images from both the right and the left carotid arteries, and that the use of an automated analysing system greatly simplifies the reading of ultrasound images with sustained low variability.
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| 38. |
- Schmidt, Johanna, 1974, et al.
(författare)
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High androgen levels protect against hypothyroidism
- 2017
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Ingår i: Acta Obstetricia Et Gynecologica Scandinavica. - : Wiley. - 0001-6349. ; 96:1, s. 39-46
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Tidskriftsartikel (refereegranskat)abstract
- IntroductionHypothyroidism is a common disorder, appearing mainly in women although less frequently found in women with polycystic ovary syndrome (PCOS). The objective was to test the hypothesis that hyperandrogenism might protect against hypothyroidism. Material and methodsThe data from three prospective follow-up studies (up to 21years) and one register study were compared: women with PCOS (Rotterdam criteria), n=25, women with Turner syndrome, n=217, a random population sample of women, n=315, and men, n=95 (the WHO MONICA study). Findings were to be verified or rejected in all females, n=553 716, from the same region. The proportion of hypothyroidism was calculated and thyroid peroxidase antibodies (TPO) in serum were measured. ResultsHypothyroidism at >50years of age was found in 8% of women with PCOS, 4% in men (PCOS vs. men; ns), 43% of women with Turner syndrome, irrespective of karyotype (p<0.001 vs. PCOS), and in 17% of postmenopausal women in the population (p<0.01 vs. PCOS). Elevated TPO were similar in PCOS and women and men in the population but higher in Turner syndrome. Hypothyroidism increased with age in all groups except PCOS women and men. In the register study, hypothyroidism was less common in women with PCOS >25years (5.5%) than in women without PCOS (6.8%) from the same region (p<0.01). ConclusionsHypothyroidism was less frequently seen in women with PCOS and in men compared with women in the general population and among women with Turner syndrome. This was not explained by altered autoimmunity or the Y-chromosome. Androgens seem to protect against hypothyroidism.
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| 39. |
- Seibert, M. Marvin, et al.
(författare)
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Single mimivirus particles intercepted and imaged with an X-ray laser
- 2011
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 470:7332, s. 78-81
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Tidskriftsartikel (refereegranskat)abstract
- X-ray lasers offer new capabilities in understanding the structure of biological systems, complex materials and matter under extreme conditions(1-4). Very short and extremely bright, coherent X-ray pulses can be used to outrun key damage processes and obtain a single diffraction pattern from a large macromolecule, a virus or a cell before the sample explodes and turns into plasma(1). The continuous diffraction pattern of non-crystalline objects permits oversampling and direct phase retrieval(2). Here we show that high-quality diffraction data can be obtained with a single X-ray pulse from a noncrystalline biological sample, a single mimivirus particle, which was injected into the pulsed beam of a hard-X-ray free-electron laser, the Linac Coherent Light Source(5). Calculations indicate that the energy deposited into the virus by the pulse heated the particle to over 100,000 K after the pulse had left the sample. The reconstructed exit wavefront (image) yielded 32-nm full-period resolution in a single exposure and showed no measurable damage. The reconstruction indicates inhomogeneous arrangement of dense material inside the virion. We expect that significantly higher resolutions will be achieved in such experiments with shorter and brighter photon pulses focused to a smaller area. The resolution in such experiments can be further extended for samples available in multiple identical copies.
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| 40. |
- Shungin, Dmitry, et al.
(författare)
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New genetic loci link adipose and insulin biology to body fat distribution.
- 2015
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 518:7538, s. 187-378
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Tidskriftsartikel (refereegranskat)abstract
- Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms.
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| 41. |
- Volgsten, Helena, 1959-, et al.
(författare)
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Psychiatric disorders in women and men up to five years after undergoing assisted reproductive technology treatment : a prospective cohort study
- 2019
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Ingår i: Human Fertility. - : Taylor & Francis Group. - 1464-7273 .- 1742-8149. ; 22:4, s. 277-282
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Tidskriftsartikel (refereegranskat)abstract
- This is a prospective cohort study with the objective to describe psychiatric disorders, such as any mood and anxiety disorders, in both women and men five years after assisted reproductive technology (ART). The Primary Care Evaluation of Mental Disorders (PRIME-MD) questionnaire, based on the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), was used as the diagnostic tool to evaluate psychiatric disorders. Logistic regression analysis was used to calculate odds ratios (ORs) and confidence interval (CI) for factors associated with psychiatric disorders at the follow-up. Overall, 278 (63.3%) women and 183 (41.7%) men filled in and returned the questionnaire. Approximately 11.5% of women and 5.5% of men fulfilled the criteria for any psychiatric diagnosis. Of these, any mood disorder was present in 9.4% of women and 4.4% of men. The major risk factor for mood or anxiety disorders at follow-up was mood or anxiety disorders at the time of the index ART. Mood disorders were not more common in women who remained childless after ART. In conclusion, these findings indicate that psychiatric disorders at five years follow-up after ART are less common than at the baseline assessment in conjunction with the ART.
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| 42. |
- Willer, Cristen J., et al.
(författare)
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Discovery and refinement of loci associated with lipid levels
- 2013
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 45:11, s. 1274-1283
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Tidskriftsartikel (refereegranskat)abstract
- Levels of low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides and total cholesterol are heritable, modifiable risk factors for coronary artery disease. To identify new loci and refine known loci influencing these lipids, we examined 188,577 individuals using genome-wide and custom genotyping arrays. We identify and annotate 157 loci associated with lipid levels at P < 5 x 10(-8), including 62 loci not previously associated with lipid levels in humans. Using dense genotyping in individuals of European, East Asian, South Asian and African ancestry, we narrow association signals in 12 loci. We find that loci associated with blood lipid levels are often associated with cardiovascular and metabolic traits, including coronary artery disease, type 2 diabetes, blood pressure, waist-hip ratio and body mass index. Our results demonstrate the value of using genetic data from individuals of diverse ancestry and provide insights into the biological mechanisms regulating blood lipids to guide future genetic, biological and therapeutic research.
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| 43. |
- Zheng, Haifeng, et al.
(författare)
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Ecoenzymatic stoichiometry can reflect microbial resource limitation, substrate quality, or both in forest soils
- 2022
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Ingår i: Soil Biology and Biochemistry. - : Elsevier BV. - 0038-0717. ; 167
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Tidskriftsartikel (refereegranskat)abstract
- Many studies have used the relative activities of extracellular enzymes associated with microbial carbon (C), nitrogen (N) and phosphorus (P) acquisition to infer the relative C vs. nutrient limitation of the microbial community. However, recent experimental and theoretical evidence has shown that the use of ecoenzymatic ratio to infer limiting microbial resources may be invalid. We added the two contrasting leaf litters ash (Fraxinus excelsior L., relatively more labile and nutrient rich) and oak (Quercus robur L.), into samples of mineral soils to validate the use of ecoenzymatic stoichiometry to reflect microbial resource limitation. The litter treatments were also combined with N and P addition treatments to push microbial communities toward stronger C limitation. The microbial resource limitations were examined in all treatments by the responses in microbial respiration, bacterial and fungal growth, microbial community composition, and by detecting the responses of microbial growth to factorial C and nutrient additions in short-term limiting factor assays (LFAs). High ratios of β-1,4-glucosidase (BG) to β-1,4-N-acetylglucosaminidase (NAG) + leucine aminopeptidase (LAP) (>2:1) contrasted with the expected reduction in C limitation after initial litter inputs. The high ratio was mainly driven by an increase in BG activity associated with high energy supply and high microbial rates of metabolism induced by added labile C substrates. During the later incubation period (7–56 days), decreasing respiration and bacterial and fungal growth rates reflected increased microbial C limitation in all treatments. An increasing BG/(NAG + LAP) ratio was in line with increasing microbial C limitation in the ash treatment where cellulose dominated as microbial C source, but a decreasing BG/(NAG + LAP) ratio was inconsistent with the temporal dynamics in microbial C limitation in the oak treatment where substrates other than cellulose (i.e., microbial necromass and lignin) dominated as C source late in the incubation. The increased BG/(NAG + LAP) ratio was in line with intensified microbial C limitation by NP addition, which was mainly due to the stimulated BG activity. In the oak and litter plus NP treatments, fungal growth was stimulated and NAG - an enzyme targeting amino sugars - was increased, presumably to meet the fungal C demand by utilizing microbial necromass - partly consisting of amino sugar polymers. Taken together, these results suggest that variation in substrate quality, availability and how these matched the present microbial energy allocation strategy and resource allocation to enzyme production caused a substantial variation in the BG/(NAG + LAP) ratio, thereby disconnecting the ratio from unambiguously reflecting the microbial resource limitation.
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| 44. |
- Zheng, Haifeng, et al.
(författare)
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Effects of common European tree species on soil microbial resource limitation, microbial communities and soil carbon
- 2022
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Ingår i: Soil Biology and Biochemistry. - : Elsevier BV. - 0038-0717. ; 172
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Tidskriftsartikel (refereegranskat)abstract
- Studies of tree species effects on soils have revealed a significant impact on soil organic carbon (SOC) stocks and the carbon (C) distribution between forest floor and mineral soil, but the underlying mechanisms including the roles of litter traits, soil properties, and microbiome remain unclear. To address this challenge, we tested the effect of six common European tree species on the quality and nutrient availability of soil organic matter (SOM) as perceived by the naturally assembled microbial communities and explored the possible links between soil enzyme activities (EAs), microbial resource limitation, and microbial community with SOC stocks. The six studied tree species (Acer pseudoplatanus L., Fraxinus excelsior L, Fagus sylvatica L., Quercus robur L., Tilia cordata L., and Picea abies L.) were planted in common garden monocultures more than 40 years ago at six sites across Denmark. In forest floor, microbial biomass C, fungal and total microbial biomass and fungi to bacteria (F/B) ratios decreased with decreasing litter quality. Ecoenzymatic stoichiometry and relative EAs indicated that microbes in spruce forest floor were more limited by phosphorus (P) than in maple, lime, and beech, while microbes in mineral soils were less P limited in spruce than in other monocultures. Mineral soil under the tree species associated with arbuscular mycorrhizal (AM) fungi had higher microbial C and P limitation, bacterial biomass and total microbial biomass than under tree species associated with ectomycorrhizal (EcM) fungi. Our results indicated that tree species with high-quality litter (i.e. AM-associated trees) had (i) higher microbial biomass and less nutrient limitation that were conducive to higher decomposition rates and lower C stocks in the forest floor, and (ii) such tree species could lead to both greater stabilization of mineral soil C by mineral-associated OM formation and greater microbial mineralization of SOM with higher microbial resource demand. The results suggest that tree species-mediated EA, microbial resource limitation and microbial community composition are important drivers of stocks and vertical distribution of SOC among tree species and between the two types of associated mycorrhiza.
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| 45. |
- Zheng, Haifeng, et al.
(författare)
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Imprint of tree species mycorrhizal association on microbial-mediated enzyme activity and stoichiometry
- 2023
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Ingår i: Functional Ecology. - : Wiley. - 0269-8463 .- 1365-2435. ; 37:5, s. 1366-1376
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the effects of tree species and their mycorrhizal association on soil processes is critical for predicting the ecosystem consequences of species shifts owing to global change and forest management decisions. While it is well established that forests dominated by different mycorrhizal types can vary in how they cycle carbon (C), nitrogen (N) and phosphorus (P), the degree to which these patterns are driven by microbial-mediated enzyme activity (EA) and ecoenzymatic stoichiometry (ES) remains elusive. Here, we synthesized the effects of mycorrhizal association on seven soil enzymes involved in microbial C, N and P acquisition and ES using data from 56 peer-reviewed papers. We found that relative to soil in ectomycorrhizal (EcM) trees, soil in arbuscular mycorrhizal (AM) trees exhibited greater activity of some C acquisition enzymes (e.g. beta-glucosidase; BG) and higher ecoenzymatic ratios of BG/NAG (N-acetyl-glucosaminidase) and BG/AP (acid phosphatase). These results supported that AM trees had rapid C and nutrient turnover rates, inorganic nutrient economics and high soil microbial C limitation. We also found evidence for an organic nutrient economy and greater soil microbial demand for nutrients in EcM trees compared to AM trees. In addition, the effect of mycorrhizal association on the activity of certain soil enzymes and enzymatic stoichiometry (i.e. BG and BG/NAG ratio) appeared to be associated with the differences in soil pH, phylogenetic group (i.e. conifers and broadleaves) and leaf habit (i.e. evergreen and deciduous) between AM and EcM trees. The results from the global meta-analysis suggested that soil EA and ES appear to play critical roles in shaping the differences in the nutrient economy between AM and EcM tree species, but leaf morphology and soil conditions should be considered in evaluations of soil processes in forests of different mycorrhizal associations. Given that most of the studies in the database were from the temperate and subtropical regions, further research in other biomes is needed to elucidate the underlying mechanisms driving the mycorrhizal effect at the global scale.
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