| 1. |
- Bijl, Wouter, et al.
(författare)
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Butterfly dichromatism primarily evolved via Darwin's, not Wallace's, model
- 2020
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Ingår i: Evolution letters. - : Oxford University Press (OUP). - 2056-3744. ; 4:6, s. 545-555
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Tidskriftsartikel (refereegranskat)abstract
- Sexual dimorphism is typically thought to result from sexual selection for elaborated male traits, as proposed by Darwin. However, natural selection could reduce expression of elaborated traits in females, as proposed by Wallace. Darwin and Wallace debated the origins of dichromatism in birds and butterflies, and although evidence in birds is roughly equal, if not in favor of Wallace's model, butterflies lack a similar scale of study. Here, we present a large‐scale comparative phylogenetic analysis of the evolution of butterfly coloration, using all European non‐hesperiid butterfly species (n = 369). We modeled evolutionary changes in coloration for each species and sex along their phylogeny, thereby estimating the rate and direction of evolution in three‐dimensional color space using a novel implementation of phylogenetic ridge regression. We show that male coloration evolved faster than female coloration, especially in strongly dichromatic clades, with male contribution to changes in dichromatism roughly twice that of females. These patterns are consistent with a classic Darwinian model of dichromatism via sexual selection on male coloration, suggesting this model was the dominant driver of dichromatism in European butterflies.
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| 2. |
- Ekström, Magnus, et al.
(författare)
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Risk of Rehospitalization and Death in Patients Hospitalized Due to Asthma
- 2021
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Ingår i: Journal of Allergy and Clinical Immunology: In Practice. - : Elsevier BV. - 2213-2198 .- 2213-2201. ; 9:5
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Tidskriftsartikel (refereegranskat)abstract
- Background: Asthma is a heterogeneous inflammatory airway disease that continues to cause considerable morbidity across the world, with poor asthma control leading to hospitalizations. Objective: The present study investigated the risk of rehospitalization, mortality, and the management of patients with asthma who had been hospitalized because of an asthma exacerbation. Methods: National Swedish health registries were linked for patients 6 years or older who were admitted to hospital because of asthma (index date) between January 1, 2006, and December 31, 2015. Exacerbations were defined as asthma-related hospitalization, emergency visits, or collection of oral steroids. Patients were followed for rehospitalizations 12 months after the index date, health care resource utilization and treatment for 36 months, and mortality to study end. Regression models for time-to-event analyses were applied to assess risk factors for rehospitalization and mortality. Results: A total of 15,691 patients (mean age, 51.5 years; 63% females) were included, of whom 1,892 (12%) were rehospitalized for asthma within 12 months. Rehospitalized patients had a markedly increased risk of subsequent asthma-related mortality (adjusted hazard ratio, 2.80; 95% CI, 1.95-4.01) compared with those not rehospitalized. Two-third of the patients were not followed up by a hospital-based specialist, and 60% did not collect enough inhaled corticosteroid doses to cover daily treatment the year postindex. Conclusions: In this study, more than 1 in 10 patients were rehospitalized because of asthma within 12 months, and rehospitalizations were associated with asthma-related mortality. Few patients were seen by a hospital-based specialist, and few used inhaled corticosteroid continuously. Closer monitoring after hospitalization is needed. © 2020 The Authors
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| 3. |
- Friberg, Magne, et al.
(författare)
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Autumn mass change and winter mass loss differ between migratory and nonmigratory butterflies
- 2023
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Ingår i: Animal Behaviour. - 0003-3472 .- 1095-8282. ; 204, s. 67-75
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Tidskriftsartikel (refereegranskat)abstract
- Poikilotherms have two major alternative strategies to deal with the inhospitable conditions of temperate winters: hibernation or migration. The vast majority of insects spend winter in a speciesspecific diapause resting stage, while others remain reproductively active after having migrated to more hospitable environments in the autumn. The butterfly clade Nymphalini offers an interesting possibility for comparisons among species adopting different strategies. Whereas most genera in this clade have evolved adult diapause, species in the genus Vanessa engage in an annual multigeneration migration cycle, leaving northern latitudes during autumn. Here, we compared two species of diapausing Aglais butterflies, A. io and A. urtica, two species of the migratory genus Vanessa, V. atalanta and V. cardui, and two morphs of Polygonia c-album, the diapausing winter morph and the direct developing hutchinsoni morph. We tested how these different species differ in resource acquisition strategy during early adult life, how the acquisition of resources affects survival in cold winter conditions and how A. io, Aglais urticae and V. atalanta differ in resting metabolism under cold conditions. The butterflies set for adult diapause (1) acquired more mass during early adult life and (2) lost less mass and had a lower resting metabolism under cold conditions. In addition, (3) the life span under cold conditions was positively related to the weight increase during early adult life in the diapausing species, but not in the migratory species. Our laboratory results demonstrate how different developmental pathways, such as diapause or direct development, can be studied by measuring mass change in living butterflies. Our expectation that migratory species would increase in mass like species set for overwintering were not met, perhaps because such studies should ideally be performed under natural conditions. (c) 2023 The Author(s). Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour. This is an open access article under the CC BY license (http://creativecommons.org/licenses/ by/4.0/).
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| 4. |
- Höök, Lars, et al.
(författare)
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High-density linkage maps and chromosome level genome assemblies unveil direction and frequency of extensive structural rearrangements in wood white butterflies (Leptidea spp.)
- 2023
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Ingår i: Chromosome Research. - : Springer Science and Business Media LLC. - 0967-3849 .- 1573-6849. ; 31:1
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Tidskriftsartikel (refereegranskat)abstract
- Karyotypes are generally conserved between closely related species and large chromosome rearrangements typically have negative fitness consequences in heterozygotes, potentially driving speciation. In the order Lepidoptera, most investigated species have the ancestral karyotype and gene synteny is often conserved across deep divergence, although examples of extensive genome reshuffling have recently been demonstrated. The genus Leptidea has an unusual level of chromosome variation and rearranged sex chromosomes, but the extent of restructuring across the rest of the genome is so far unknown. To explore the genomes of the wood white (Leptidea) species complex, we generated eight genome assemblies using a combination of 10X linked reads and HiC data, and improved them using linkage maps for two populations of the common wood white (L. sinapis) with distinct karyotypes. Synteny analysis revealed an extensive amount of rearrangements, both compared to the ancestral karyotype and between the Leptidea species, where only one of the three Z chromosomes was conserved across all comparisons. Most restructuring was explained by fissions and fusions, while translocations appear relatively rare. We further detected several examples of segregating rearrangement polymorphisms supporting a highly dynamic genome evolution in this clade. Fusion breakpoints were enriched for LINEs and LTR elements, which suggests that ectopic recombination might be an important driver in the formation of new chromosomes. Our results show that chromosome count alone may conceal the extent of genome restructuring and we propose that the amount of genome evolution in Lepidoptera might still be underestimated due to lack of taxonomic sampling.
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| 5. |
- Ittonen, Mats, 1989-, et al.
(författare)
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Local adaptation to seasonal cues at the fronts of two parallel, climate-induced butterfly range expansions
- 2022
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 25:9, s. 2022-2033
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Tidskriftsartikel (refereegranskat)abstract
- Climate change allows species to expand polewards, but non-changing environmental features may limit expansions. Daylength is unaffected by climate and drives life cycle timing in many animals and plants. Because daylength varies over latitudes, poleward-expanding populations must adapt to new daylength conditions. We studied local adaptation to daylength in the butterfly Lasiommata megera, which is expanding northwards along several routes in Europe. Using common garden laboratory experiments with controlled daylengths, we compared diapause induction between populations from the southern-Swedish core range and recently established marginal populations from two independent expansion fronts in Sweden. Caterpillars from the northern populations entered diapause in clearly longer daylengths than those from southern populations, with the exception of caterpillars from one geographically isolated population. The northern populations have repeatedly and rapidly adapted to their local daylengths, indicating that the common use of daylength as seasonal cue need not strongly limit climate-induced insect range expansions.
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| 6. |
- Janson, Christer, et al.
(författare)
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High use of short-acting beta(2)-agonists in COPD is associated with an increased risk of exacerbations and mortality
- 2023
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Ingår i: ERJ Open Research. - : European Respiratory Society. - 2312-0541. ; 9:3
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Tidskriftsartikel (refereegranskat)abstract
- Background: Short-acting beta(2)-agonist (SABA) overuse has been associated with an increased risk of exacerbations in asthma; however, less is known about SABA use in COPD. Our aim was to describe SABA use and investigate potential associations between high SABA use and the risk of future exacerbations and mortality in COPD.Methods: This observational study identified COPD patients in primary care medical records in Sweden. Data were linked to the National Patient Registry, the Prescribed Drug Registry and the Cause of Death Registry. The index date was 12 months after the date of COPD diagnosis. During a 12-month prior to index baseline period, information on SABA use was collected. Patients were followed with respect to exacerbations and mortality for 12 months post index.Results: Of the 19 794 COPD patients included (mean age 69.1 years, 53.3% females), 15.5% and 7.0% had collected >= 3 or >= 6 SABA canisters during the baseline period, respectively. A higher level of SABA use (>= 6 canisters) was independently associated with a higher risk of both moderate and severe exacerbations (hazard ratio (HR) 1.28 (95% CI 1.17.1.40) and 1.76 (95% CI 1.50.2.06), respectively) during follow-up. In total, 673 (3.4%) patients died during the 12-month follow-up period. An independent association was found between high SABA use and overall mortality (HR 1.60, 95% CI 1.07.2.39). This association, however, was not found in patients using inhaled corticosteroids as maintenance treatment.Conclusion: In COPD patients in Sweden, high SABA use is relatively common and associated with a higher risk of exacerbations and all-cause mortality.
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| 7. |
- Janson, Christer, et al.
(författare)
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Management and Risk of Mortality in Patients Hospitalised Due to a First Severe COPD Exacerbation
- 2020
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Ingår i: The International Journal of Chronic Obstructive Pulmonary Disease. - : DOVE MEDICAL PRESS LTD. - 1176-9106 .- 1178-2005. ; 15, s. 2673-2682
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Tidskriftsartikel (refereegranskat)abstract
- Background: Reducing the need for hospitalisation in patients with chronic obstructive pulmonary disease (COPD) is an important goal in COPD management. The aim of this study was to evaluate re-hospitalisation, treatment, comorbidities and mortality in patients with COPD who were hospitalised for the first time due to a COPD exacerbation.Methods: This was a retrospective, population-based observational cohort study of Swedish patients using linked data from three mandatory national health registries to assess re-hospitalisation rates, medication use and mortality. Rate of hospitalisation was calculated using the number of events divided by the number of person-years at risk; risk of all-cause and COPD-related mortality were assessed using Cox proportional hazard models.Results: In total, 51,247 patients were identified over 10 years; 35% of patients were not using inhaled corticosteroid, long-acting muscarinic antagonist or long-acting beta(2)-agonist treatment prior to hospitalisation, 38% of whom continued without treatment after being discharged. Re-hospitalisation due to a second severe exacerbation occurred in 11.5%, 17.8% and 24% of the patients within 30, 90 and 365 days, respectively. Furthermore, 24% died during the first year following hospitalisation and risk of all-cause and COPD-related mortality increased with every subsequent re-hospitalisation. Comorbidities, including ischaemic heart disease, heart failure and pneumonia, were more common amongst patients who were re-hospitalised than those who were not.Conclusion: Following hospitalisation for first severe COPD exacerbation, many patients did not collect the treatment recommended by current guidelines. Risk of mortality increased with every subsequent re-hospitalisation. Patients with concurrent comorbidities had an increased risk of being re-hospitalised.
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| 8. |
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| 9. |
- Lukhtanov, Vladimir A., et al.
(författare)
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Incomplete Sterility of Chromosomal Hybrids : Implications for Karyotype Evolution and Homoploid Hybrid Speciation
- 2020
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Ingår i: Frontiers in Genetics. - : Frontiers Media SA. - 1664-8021. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Heterozygotes for major chromosomal rearrangements such as fusions and fissions are expected to display a high level of sterility due to problems during meiosis. However, some species, especially plants and animals with holocentric chromosomes, are known to tolerate chromosomal heterozygosity even for multiple rearrangements. Here, we studied male meiotic chromosome behavior in four hybrid generations (F1-F4) between two chromosomal races of the Wood White butterfly Leptidea sinapis differentiated by at least 24 chromosomal fusions/fissions. Previous work showed that these hybrids were fertile, although their fertility was reduced as compared to crosses within chromosomal races. We demonstrate that (i) F1 hybrids are highly heterozygous with nearly all chromosomes participating in the formation of trivalents at the first meiotic division, and (ii) that from F1 to F4 the number of trivalents decreases and the number of bivalents increases. We argue that the observed process of chromosome sorting would, if continued, result in a new homozygous chromosomal race, i.e., in a new karyotype with intermediate chromosome number and, possibly, in a new incipient homoploid hybrid species. We also discuss the segregational model of karyotype evolution and the chromosomal model of homoploid hybrid speciation.
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| 10. |
- Melén, Erik, et al.
(författare)
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Short-acting β2 -agonist use and asthma exacerbations in Swedish children: A SABINA Junior study.
- 2022
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Ingår i: Pediatric allergy and immunology : official publication of the European Society of Pediatric Allergy and Immunology. - : Wiley. - 1399-3038 .- 0905-6157. ; 33:11
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Tidskriftsartikel (refereegranskat)abstract
- In adults and adolescents with asthma, use of ≥3 short-acting β2 -agonist (SABA) canisters/year is associated with increased exacerbation risk. Whether this association is present in younger children remains unknown. In this SABA use IN Asthma (SABINA) Junior study, we assessed the association of SABA collection with exacerbation risk in the general Swedish pediatric asthma population.This population-based cohort study utilized linked data from the Swedish national healthcare registries involving patients with asthma (<18years) treated in secondary care between 2006-2015. Exacerbation risk, by baseline SABA collection (0-2 vs. ≥3 canisters, further examined as ordinal/continuous variable) and stratified on comorbid atopic disease (allergic rhinitis, dermatitis and eczema, and food/other allergies), was assessed for 1-year follow-up using negative binomial regression.Of 219,561 patients assessed, 45.4%, 31.7%, and 26.5% of patients aged 0-5, 6-11, and 12-17years, respectively, collected ≥3 SABA canisters during the baseline year (high use). Collection of ≥3 SABA canisters (vs. 0-2) was associated with increased exacerbation risk during follow-up (incidence rate ratios [95% confidence interval]: 1.35 [1.29-1.42], 1.22 [1.15-1.29], and 1.26 [1.19-1.34] for 0-5-, 6-11-, and 12-17-year-olds, respectively); the association persisted with SABA as a continuous variable and was stronger among patients without atopic diseases (32%-44% increased risk versus. 14%-21% for those with atopic disease across groups).High SABA use was associated with increased asthma exacerbation risk in children, particularly in those without comorbid atopic diseases, emphasizing the need for asthma medication reviews and reformative initiatives by caregivers and healthcare providers on SABA use.
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