88 results on '"Friberg M"'
Search Results
2. PCR57 A Qualitative Interview Study to Evaluate Single-Tablet Combination Therapy (STCT) Within a Phase 3 Pulmonary Arterial Hypertension (PAH) Clinical Trial – Interim Analysis
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Davis, S., primary, Randall, J., additional, Linder, J., additional, Rafalski, J., additional, Hughes, M., additional, Rodriguez, A.A., additional, Friberg, M., additional, and Burbridge, C., additional
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- 2023
- Full Text
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3. Macitentan tadalafil Fixed Dose Combination (FDC) in treatment-naive and prior monotherapy patients with Pulmonary Arterial Hypertension (PAH): insights from A DUE
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Gruenig, E, primary, Jansa, P, additional, Fan, F, additional, Friberg, M, additional, Lassen, C, additional, Pannaux, M, additional, Rofael, H, additional, and Chin, K, additional
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- 2023
- Full Text
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4. Components of local adaptation and divergence in pollination efficacy in a coevolving species interaction
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Gross, K., Undin, Malin, Thompson, J. N., Friberg, M., Gross, K., Undin, Malin, Thompson, J. N., and Friberg, M.
- Abstract
Selection leading to adaptation to interactions may generate rapid evolutionary feedbacks and drive diversification of species interactions. The challenge is to understand how the many traits of interacting species combine to shape local adaptation in ways directly or indirectly resulting in diversification. We used the well-studied interactions between Lithophragma plants (Saxifragaceae) and Greya moths (Prodoxidae) to evaluate how plants and moths together contributed to local divergence in pollination efficacy. Specifically, we studied L. bolanderi and its two specialized Greya moth pollinators in two contrasting environments in the Sierra Nevada in California. Both moths pollinate L. bolanderi during nectaring, one of them–G. politella–also while ovipositing through the floral corolla into the ovary. First, field surveys of floral visitors and the presence of G. politella eggs and larvae in developing capsules showed that one population was visited only by G. politella and few other pollinators, whereas the other was visited by both Greya species and other pollinators. Second, L. bolanderi in these two natural populations differed in several floral traits putatively important for pollination efficacy. Third, laboratory experiments with greenhouse-grown plants and field-collected moths showed that L. bolanderi was more efficiently pollinated by local compared to nonlocal nectaring moths of both species. Pollination efficacy of ovipositing G. politella was also higher for local moths for the L. bolanderi population, which relies more heavily on this species in nature. Finally, time-lapse photography in the laboratory showed that G. politella from different populations differed in oviposition behavior, suggesting the potential for local adaptation also among Greya populations. Collectively, our results are a rare example of components of local adaptation contributing to divergence in pollination efficacy in a coevolving interaction and, thus, provide insights into
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- 2023
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5. The efficacy and safety of macitentan in Fontan-palliated patients: results of the 52-week randomised, placebo-controlled RUBATO trial
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Clift, P, primary, Berger, F, additional, Sondergaard, L, additional, Antonova, P, additional, Disney, P, additional, Nicolarsen, J, additional, Thambo, J B, additional, Tomkiewicz Pajak, L, additional, Wang, J K, additional, Schophuus Jensen, A, additional, Burgess, G, additional, Efficace, M, additional, Friberg, M, additional, Lassen, C, additional, and d'Udekem, Y, additional
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- 2022
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6. Incomplete sterility of chromosomal hybrids:implications for karyotype evolution and homoploid hybrid speciation
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Lukhtanov, V. A. (Vladimir A.), Dincă, V. (Vlad), Friberg, M. (Magne), Vila, R. (Roger), and Wiklund, C. (Christer)
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Lepidoptera ,Pieridae ,fertility ,inviability ,chromosome ,hybridization ,segregation ,inverted meiosis - 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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- 2020
7. Lack of gene flow:narrow and dispersed differentiation islands in a triplet of Leptidea butterfly species
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Talla, V. (Venkat), Johansson, A. (Anna), Dincă, V. (Vlad), Vila, R. (Roger), Friberg, M. (Magne), Wiklund, C. (Christer), and Backström, N. (Niclas)
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Lepidoptera ,cryptic species ,speciation ,genome scan ,wood white butterflies ,Leptidea - Abstract
Genome scans in recently separated species can inform on molecular mechanisms and evolutionary processes driving divergence. Large‐scale polymorphism data from multiple species pairs are also key to investigate the repeatability of divergence—whether radiations tend to show parallel responses to similar selection pressures and/or underlying molecular forces. Here, we used whole‐genome resequencing data from six wood white (Leptidea sp.) butterfly populations, representing three closely related species with karyomorph variation, to infer the species’ demographic history and characterize patterns of genomic diversity and differentiation. The analyses supported previously established species relationships, and there was no evidence for postdivergence gene flow. We identified significant intraspecific genetic structure, in particular between karyomorph extremes in the wood white (L. sinapis)—a species with a remarkable chromosome number cline across the distribution range. The genomic landscapes of differentiation were erratic, and outlier regions were narrow and dispersed. Highly differentiated (FST) regions generally had low genetic diversity (θπ), but increased absolute divergence (DXY) and excess of rare frequency variants (low Tajima’s D). A minority of differentiation peaks were shared across species and population comparisons. However, highly differentiated regions contained genes with overrepresented functions related to metabolism, response to stimulus and cellular processes, indicating recurrent directional selection on a specific set of traits in all comparisons. In contrast to the majority of genome scans in recently diverged lineages, our data suggest that divergence landscapes in Leptidea have been shaped by directional selection and genetic drift rather than stable recombination landscapes and/or introgression.
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- 2019
8. Impact of prolonged storage of clinical samples at 4 degrees C on the recovery of dermatophytes by culture or PCR analysis
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Nilsson, Kenneth, Friberg, M., Rollman, Ola, Tano, Eva, Nilsson, Kenneth, Friberg, M., Rollman, Ola, and Tano, Eva
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Dermatophytes are common pathogens in superficial mycoses that are routinely identified by culture or PCR analysis of freshly collected skin, nail or hair specimens. Although clinical samples are normally processed without delay, practical or research issues may necessitate sample storage until later analysis. However, the influence of extended sample storage on the ability to recover fungi by culture vs. PCR analysis has not been specifically studied. Here, a total of 172 dermatological samples collected from 2013-2015 were examined before and after refrigerated storage at 4 degrees C for 10.2-32.3 (mean 25.6) months. By culture, 35% of the dermatophyte-containing fresh samples remained positive at reexamination. At species level, only 19% of initially Trichophyton rubrum-positive samples yielded a positive result after refrigeration, whereas few samples containing Trichophyton violaceum, Microsporum canis or Microsporum audouinii remained culture-positive. Using PCR, 76% of dermatophyte DNA-positive fresh samples were still positive at re-analysis. Notably, 92% of the samples targeted by the T. rubrum DNA primer remained positive after storage. Hence, PCR analysis is more favourable than cultivation with regard to the detectability of dermatophytes in long-term refrigerated clinical samples.
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- 2019
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9. Ten lessons for good practice for the INHERIT triple win: Health, equity, and environmental sustainability
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Bell, R., Khan, M., Romeo-Velilla, M., Stegeman, I., Godfrey, A., Taylor, T., Morris, G., Staatsen, B., Van der, Vliet, N., Kruize, H., Anthun, K.S., Lillefjell, M., Espnes, G.A., Chiabai, A., de Jalón, S.G., Quiroga, S., Martinez-Juarez, P., Máca, V., Zverinová, I., Scasny, M., Marques, S., Craveiro, D., Westerink, J., Spelt, H., Karnaki, P., Strube, R., Merritt, A.-S., Friberg, M., Bélorgey, N., Vos, M., Gjorgjev, D., Upelniece, I., Costongs, C., Bell, R., Khan, M., Romeo-Velilla, M., Stegeman, I., Godfrey, A., Taylor, T., Morris, G., Staatsen, B., Van der, Vliet, N., Kruize, H., Anthun, K.S., Lillefjell, M., Espnes, G.A., Chiabai, A., de Jalón, S.G., Quiroga, S., Martinez-Juarez, P., Máca, V., Zverinová, I., Scasny, M., Marques, S., Craveiro, D., Westerink, J., Spelt, H., Karnaki, P., Strube, R., Merritt, A.-S., Friberg, M., Bélorgey, N., Vos, M., Gjorgjev, D., Upelniece, I., and Costongs, C.
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The world s challenges of climate change, damage to ecosystems, and social and health inequalities require changes in human behaviours at every level of organisation, among governments, business, communities, and individuals. An important question is how behaviour change can be enabled and supported at the scale and speed required. The research reported in this paper describes important lessons for good practice in changing contexts to modify behaviours for a triple win for health, equity and environmental sustainability. Authors synthesised learning from qualitative, quantitative and cost benefit evaluations of 15 case studies conducted in 12 countries in Europe. The case studies address ways of living (green spaces and energy efficient housing), moving (active transport) and consuming (healthy and sustainable diets) that support the triple win. Ten lessons for good practice were identified. These include bringing a triple win mindset to policy and practice in planning interventions, with potential to improve environmental sustainability, health and equity at the same time. The lessons for good practice are intended to support governmental and non-governmental actors, practitioners and researchers planning to work across sectors to achieve mutual benefits for health and environmental sustainability and in particular to benefit poorer and more socio-economically disadvantaged groups. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.
- Published
- 2019
10. Dissecting the effects of selection and mutation on genetic diversity in three wood white (Leptidea) butterfly species
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Talla, V. (Venkat), Soler, L. (Lucile), Kawakami, T. (Takeshi), Dincă, V. (Vlad), Vila, R. (Roger), Friberg, M. (Magne), Wiklund, C. (Christer), Backström, N. (Niclas), Talla, V. (Venkat), Soler, L. (Lucile), Kawakami, T. (Takeshi), Dincă, V. (Vlad), Vila, R. (Roger), Friberg, M. (Magne), Wiklund, C. (Christer), and Backström, N. (Niclas)
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The relative role of natural selection and genetic drift in evolution is a major topic of debate in evolutionary biology. Most knowledge spring from a small group of organisms and originate from before it was possible to generate genome-wide data on genetic variation. Hence, it is necessary to extend to a larger number of taxonomic groups, descriptive and hypothesis-based research aiming at understanding the proximate and ultimate mechanisms underlying both levels of genetic polymorphism and the efficiency of natural selection. In this study, we used data from 60 whole-genome resequenced individuals of three cryptic butterfly species (Leptidea sp.), together with novel gene annotation information and population recombination data. We characterized the overall prevalence of natural selection and investigated the effects of mutation and linked selection on regional variation in nucleotide diversity. Our analyses showed that genome-wide diversity and rate of adaptive substitutions were comparatively low, whereas nonsynonymous to synonymous polymorphism and substitution levels were comparatively high in Leptidea, suggesting small long-term effective population sizes. Still, negative selection on linked sites (background selection) has resulted in reduced nucleotide diversity in regions with relatively high gene density and low recombination rate. We also found a significant effect of mutation rate variation on levels of polymorphism. Finally, there were considerable population differences in levels of genetic diversity and pervasiveness of selection against slightly deleterious alleles, in line with expectations from differences in estimated effective population sizes.
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- 2019
11. Versatility of multivalent orientation, inverted meiosis, and rescued fitness in holocentric chromosomal hybrids
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Lukhtanov, V. A. (Vladimir A.), Dincă, V. (Vlad), Friberg, M. (Magne), Šíchová, J. (Jindra), Olofsson, M. (Martin), Vila, R. (Roger), Marec, F. (František), Wiklund, C. (Christer), Lukhtanov, V. A. (Vladimir A.), Dincă, V. (Vlad), Friberg, M. (Magne), Šíchová, J. (Jindra), Olofsson, M. (Martin), Vila, R. (Roger), Marec, F. (František), and Wiklund, C. (Christer)
- Abstract
Chromosomal rearrangements (e.g., fusions/fissions) have the potential to drive speciation. However, their accumulation in a population is generally viewed as unlikely, because chromosomal heterozygosity should lead to meiotic problems and aneuploid gametes. Canonical meiosis involves segregation of homologous chromosomes in meiosis I and sister chromatid segregation during meiosis II. In organisms with holocentric chromosomes, which are characterized by kinetic activity distributed along almost the entire chromosome length, this order may be inverted depending on their metaphase I orientation. Here we analyzed the evolutionary role of this intrinsic versatility of holocentric chromosomes, which is not available to monocentric ones, by studying F1 to F4 hybrids between two chromosomal races of the Wood White butterfly (Leptidea sinapis), separated by at least 24 chromosomal fusions/fissions. We found that these chromosomal rearrangements resulted in multiple meiotic multivalents, and, contrary to the theoretical prediction, the hybrids displayed relatively high reproductive fitness (42% of that of the control lines) and regular behavior of meiotic chromosomes. In the hybrids, we also discovered inverted meiosis, in which the first and critical stage of chromosome number reduction was replaced by the less risky stage of sister chromatid separation. We hypothesize that the ability to invert the order of the main meiotic events facilitates proper chromosome segregation and hence rescues fertility and viability in chromosomal hybrids, potentially promoting dynamic karyotype evolution and chromosomal speciation.
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- 2018
12. EFFECTS OF NATURAL AND SEXUAL SELECTION ON ADAPTIVE POPULATION DIVERGENCE AND PREMATING ISOLATION IN A DAMSELFLY
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Erik Svensson, Eroukhmanoff, F., and Friberg, M.
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Male ,Sexual Behavior, Animal ,Insecta ,Reproduction ,Genetics ,Animals ,Female ,Selection, Genetic ,General Agricultural and Biological Sciences ,Adaptation, Physiological ,Biological Evolution ,Ecology, Evolution, Behavior and Systematics - Abstract
The relative strength of different types of directional selection has seldom been compared directly in natural populations. A recent meta-analysis of phenotypic selection studies in natural populations suggested that directional sexual selection may be stronger in magnitude than directional natural selection, although this pattern may have partly been confounded by the different time scales over which selection was estimated. Knowledge about the strength of different types of selection is of general interest for understanding how selective forces affect adaptive population divergence and how they may influence speciation. We studied divergent selection on morphology in parapatric, natural damselfly (Calopteryx splendens) populations. Sexual selection was stronger than natural selection measured on the same traits, irrespective of the time scale over which sexual selection was measured. Visualization of the fitness surfaces indicated that population divergence in overall morphology is more strongly influenced by divergent sexual selection rather than natural selection. Courtship success of experimental immigrant males was lower than that of resident males, indicating incipient sexual isolation between these populations. We conclude that current and strong sexual selection promotes adaptive population divergence in this species and that premating sexual isolation may have arisen as a correlated response to divergent sexual selection. Our results highlight the importance of sexual selection, rather than natural selection in the adaptive radiation of odonates, and supports previous suggestions that divergent sexual selection promotes speciation in this group.
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- 2006
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13. Floral scent contributes to interaction specificity in coevolving plants and their insect pollinators
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Friberg, M, Schwind, C, Roark, LC, Raguso, RA, and Thompson, JN
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Plant-insect communication ,Oviposition ,Speciation ,Flowers ,Moths ,Species Specificity ,Olfactometry ,Animals ,Temperament ,Pollination ,Geographic mosaics ,Chemotaxis ,Saxifragaceae ,Host specialization ,Biological Sciences ,Olfactory Perception ,Biological Evolution ,Circadian Rhythm ,Spectrophotometry ,Odorants ,Chemical Sciences ,Diurnal rhythm ,Female ,Entomology ,Environmental Sciences ,Coevolution - Abstract
© 2014, Springer Science+Business Media New York. Chemical defenses, repellents, and attractants are important shapers of species interactions. Chemical attractants could contribute to the divergence of coevolving plant-insect interactions, if pollinators are especially responsive to signals from the local plant species. We experimentally investigated patterns of daily floral scent production in three Lithophragma species (Saxifragaceae) that are geographically isolated and tested how scent divergence affects attraction of their major pollinator—the floral parasitic moth Greya politella (Prodoxidae). These moths oviposit through the corolla while simultaneously pollinating the flower with pollen adhering to the abdomen. The complex and species-specific floral scent profiles were emitted in higher amounts during the day, when these day-flying moths are active. There was minimal divergence found in petal color, which is another potential floral attractant. Female moths responded most strongly to scent from their local host species in olfactometer bioassays, and were more likely to oviposit in, and thereby pollinate, their local host species in no-choice trials. The results suggest that floral scent is an important attractant in this interaction. Local specialization in the pollinator response to a highly specific plant chemistry, thus, has the potential to contribute importantly to patterns of interaction specificity among coevolving plants and highly specialized pollinators.
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- 2014
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14. Decoupling of female host plant preference and offspring performance in relative specialist and generalist butterflies
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Friberg, M., Posledovich, Diana, Wiklund, Christer, Friberg, M., Posledovich, Diana, and Wiklund, Christer
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The preference-performance hypothesis posits that the host plant range of plant-feeding insects is ultimately limited by larval costs associated with feeding on multiple resources, and that female egg-laying preferences evolve in response to these costs. The trade-off of either using few host plant species and being a strong competitor on them due to effective utilization or using a wide host plant range but being a poor competitor is further predicted to result in host plant specialization. This follows under the hypothesis that both females and offspring are ultimately favoured by utilizing only the most suitable host(s). We develop an experimental approach to identify such trade-offs, i.e. larval costs associated with being a host generalist, and apply a suite of experiments to two sympatric and syntopic populations of the closely related butterflies Pieris napi and Pieris rapae. These butterflies show variation in their level of host specialization, which allowed comparisons between more and less specialized species and between families within species. Our results show that, first, the link between female host preference and offspring performance was not significantly stronger in the specialist compared to the generalist species. Second, the offspring of the host plant specialist did not outperform the offspring of the generalist on the former's most preferred host plant species. Finally, the more generalized species, or families within species, did not show higher survival or consistently higher growth rates than the specialists on the less preferred plants. Thus, the preference and performance traits appear to evolve as largely separated units.
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- 2015
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15. Structural architecture of the southern and middle Urals foreland from reflection seismic profiles
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Brown, D., Juhlin, C., Tryggvason, A., Friberg, M., Rybalka, A., Puchkov, V., and Petrov, G.
- Abstract
The Urals Seismic Experiment and Integrated Studies (URSEIS), Mikhailovsky, and Europrobe's Seismic Reflection Profiling in the Urals (ESRU) reflection seismic profiles provide constraints for the construction of balanced and restored geological cross sections across the southern and middle Urals foreland. The profiles image the transition from the undeformed foreland basin to the frontal structure of the foreland thrust and fold belt, the location of the basal detachment, and the location of the ramp down into the middle or lower crust. In the URSEIS and ESRU profiles, the transition into the undeformed foreland basin is imaged as an emergent west-vergent thrust that deforms a westward thickening package of reflections related to synorogenic sediments, whereas in the Mikhailovsky profile, it is a buried system of imbricate thrusts. In all three data sets, the western flank of the foreland thrust and fold belt is imaged in the seismic data as an imbricate thrust system developed above a basal detachment located in either the upper part of the Neoproterozoic basement sediments or the lower part of the Paleozoic continental margin sediments. Truncation of reflections related to the undeformed sediments in the footwall to the imbricate thrust system mark the location of the ramp down of the basal detachment into the middle or lower crust beneath the basement-cored anticlines along the eastern flank of the thrust belt. The URSEIS and ESRU profiles image the basement-cored anticlines as predominantly east dipping reflections that extend into the middle and lower crust. Rocks in these anticlines record at least one phase of pre-Uralide deformation and, at least in part, the reflectivity is due to this deformation event. Balanced and restored cross sections constructed along the three profiles indicate that the minimum shortening is about 20–25 km.
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- 2006
16. Intraspecific variation in body size and the rate of reproduction in female insects - adaptive allometry or biophysical constraint?
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Berger, David, Olofsson, M., Friberg, M., Karlsson, B., Wiklund, C., Gotthard, K., Berger, David, Olofsson, M., Friberg, M., Karlsson, B., Wiklund, C., and Gotthard, K.
- Abstract
1. A high rate of reproduction may be costly if ecological factors limit immediate reproductive output as a fast metabolism compromises own future survival. Individuals with more reserves need more time and opportunity to realize their reproductive potential. Theory therefore predicts that the reproductive rate, defined as the investment in early reproduction in proportion to total potential, should decrease with body size within species. 2. However, metabolic constraints on body size- and temperature-dependent biological rates may impede biophysical adaptation. Furthermore, the sequential manner resources that are allocated to somatic vs. reproductive tissue during ontogeny may, when juveniles develop in unpredictable environments, further contribute to non-adaptive variation in adult reproductive rates. 3. With a model on female egg laying in insects, we demonstrate how variation in body reserves is predicted to affect reproductive rate under different ecological scenarios. Small females always have higher reproductive rates but shorter lifespans. However, incorporation of female host selectivity leads to more similar reproductive rates among female size classes, and oviposition behaviour is predicted to co-evolve with reproductive rate, resulting in small females being more selective in their choice and gaining relatively more from it. 4. We fed simulations with data on the butterfly Pararge aegeria to compare model predictions with reproductive rates of wild butterflies. However, simulated reproductive allometry was a poor predictor of that observed. Instead, reproductive rates were better explained as a product of metabolic constraints on rates of egg maturation, and an empirically derived positive allometry between reproductive potential and size. However, fitness is insensitive to moderate deviations in reproductive rate when oviposition behaviour is allowed to co-evolve in the simulations, suggesting that behavioural compensation may mitigate putative metabo
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- 2012
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17. Prediction of Transcription Factor Binding Sites using Results from Genetical Genomics Investigations
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Von Rohr, P., Friberg, M., Kadarmideen, Haja, Von Rohr, P., Friberg, M., and Kadarmideen, Haja
- Published
- 2007
18. Crustal structure of the Middle Urals based on reflection seismic data
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Kashubin, S., Juhlin, Christopher, Friberg, M., Rybalka, A., Petrov, G., Kashubin, A., Bliznetsov, M., Steer, D., Kashubin, S., Juhlin, Christopher, Friberg, M., Rybalka, A., Petrov, G., Kashubin, A., Bliznetsov, M., and Steer, D.
- Published
- 2006
19. Crustal structure of the Middle Urals based on seismic reflection data
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Kashubin, S., Juhlin, Christopher, Friberg, M., Rybalka, A., Petrov, G., Kashubin, Artem, Bliznetsov, M., Steer, D., Kashubin, S., Juhlin, Christopher, Friberg, M., Rybalka, A., Petrov, G., Kashubin, Artem, Bliznetsov, M., and Steer, D.
- Abstract
EUROPROBE-related seismic reflection surveys in the Middle Urals, Russia (latitude 56-62°) since 1993 have led to an increased understanding of the crustal structure and tectonic evolution of this region. A 400 km long profile now extends from the foreland basin in the west well into the West Siberian Basin in the east. Bivergent structures characterize the upper crust of the Uralide orogen, whereas the middle and lower crust generally contain gently west-dipping reflections. A crustal root is imaged down to almost 60 km beneath the exposed Urals. Below the foreland and the West Siberian Basin the lower crustal reflectivity is pronounced and the Moho lies at a depth of 40-45 km. Below the foreland on the recently acquired Serebrianka-Beriozovka profile, two sets of late arriving (20-25 s) reflections are present. One set reflects from a zone in the mantle at about 60-70 km depth that strikes ENE and dips about 45° to the SSE. The other set may represent imbricated lower crust. Major events during the Palaeozoic tectonic evolution of the Middle Urals were: continental and oceanic rifting (Late Cambrian to Early Ordovician); development of a passive continental margin (Mid-Ordovician to Mid-Carboniferous); intra-oceanic subduction below the Tagil arc (Silurian to Devonian); east-dipping subduction of the Baltica plate (Silurian to Early Devonian); possible subduction reversal with formation of the Alapaevsk island arc and the Krasnoturjinsk-Petrokamensk active continental margin (Devonian to Early Carboniferous); active building of a mountain belt and intrusion of collision-related granitic plutons (Carboniferous to Permian).
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- 2006
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20. Palaeozoic tectonic evolution of the Middle Urals in the light of the ESRU seismic experiments
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Friberg, M, Juhlin, C, Beckholmen, M, Petrov, M, Green, AG, Friberg, M, Juhlin, C, Beckholmen, M, Petrov, M, and Green, AG
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- 2002
21. Fully automatic segmentation of the Hippocampus in MR image
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Starck, G., Borga, Magnus, Friberg, M., Olsson, E., Ribbelin, S., Knutsson, Hans, Ekholm, S., Malmgren, H., Starck, G., Borga, Magnus, Friberg, M., Olsson, E., Ribbelin, S., Knutsson, Hans, Ekholm, S., and Malmgren, H.
- Published
- 2002
22. Europrobe seismic reflection profiling across the eastern Middle Urals and West Siberian Basin
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Friberg, M, Juhlin, Christopher, Green, AG, Horstmeyer, H, Roth, J, Rybalka, A, Bliznetsov, M, Friberg, M, Juhlin, Christopher, Green, AG, Horstmeyer, H, Roth, J, Rybalka, A, and Bliznetsov, M
- Abstract
New deep seismic reflection data provide images of the crust and uppermost mantle underlying the eastern Middle Urals and adjacent West Siberian Basin. Distinct truncations of reflections delineate the late-orogenic strike-slip Sisert Fault extending vertically to ∼28 km depth, and two gently E-dipping reflection zones, traceable to 15–18 km depth, probably represent normal faults associated with the opening of the West Siberian Basin. A possible remnant Palaeozoic subduction zone in the lower crust under the West Siberian Basin is visible as a gently SW-dipping zone of pronounced reflectivity truncated by the Moho. Continuity of shallow to intermediate-depth reflections suggest that Palaeozoic accreted island-arc terranes and overlying molasse sequences exposed in the hinterland of the Urals form the basement for Triassic and younger deposits in the West Siberian Basin. A highly reflective lower crust overlies a transparent mantle at about 43 km depth along the entire 100 km long seismic reflection section, suggesting that the lower crust and Moho below the eastern Middle Urals and West Siberian Basin have the same origin.
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- 2001
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23. Crustal structure of the Middle Urals: Results from the (ESRU) Europrobe seismic reflection profiling in the Urals experiments
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Juhlin, Christopher, Friberg, M, Echtler, HP, Hismatulin, T, Rybalka, A, Green, AG, Ansorge, J, Juhlin, Christopher, Friberg, M, Echtler, HP, Hismatulin, T, Rybalka, A, Green, AG, and Ansorge, J
- Abstract
As a contribution to Europrobe's seismic reflection profiling in the Urals (ESRU)project, three overlapping seismic reflection data sets were acquired in the Middle Urals. A 56 km long profile was registered over the Europe-Asia suture, two 25 km long intersecting profiles were collected over the Urals superdeep borehole (SG4), and an 80 km long profile was recorded eastward extending east toward the West Siberian Basin. Reflections on the seismic sections delineate several major middle to late Paleozoic thrust zones in the upper crust. These thrust zones have a bivergent geometry with westerly vergence west of the Uralian orogenic axis and easterly vergence to the east. The principal terrane boundaries are the Main Uralian Thrust Fault in the west and the Trans- Uralian Thrust Zone in the east. Normal faults are spatially associated with former thrust faults, or they crosscut them. The thrust and normal faults can be confidently correlated with surface geological features. Near-vertical and wide-angle seismic reflection profiling reveals thickening of the crust from about 45 km to approximately 53 km below the central axis of the Urals. East and west of the root zone, the lower crust is reflective, particularly toward the West Siberian Basin. We interpret the reflectivity of the crust below the East European Craton as pre-Uralian, whereas that toward the West Siberian Basin is interpreted as late orogenic. Although the principal tectonic features imaged by the seismic sections are probably of Paleozoic age, a post-Paleozoic origin for the lower crustal reflectivity in the east cannot be ruled out.
- Published
- 1998
24. Structure of the middle Urals, east of the Main Uralian Fault
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Friberg, M, Petrov, GA, Friberg, M, and Petrov, GA
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In the Middle Urals, volcanic-are and back-are basin rocks of Ordovician to Devonian age occur in the Tagil Synform. These outboard terranes were thrust westwards in the late Carboniferous onto continental margin associations of late Proterozoic and Palae, Addresses: Friberg M, Uppsala Univ, Dept Geophys, Villavagen 16, S-75236 Uppsala, Sweden. Uppsala Univ, Dept Geophys, S-75236 Uppsala, Sweden. Urals Geol Mapping Expedit, UralGeolCom, Ekaterinburg, Sverdlovsk Dist, Russia.
- Published
- 1998
25. Structure of the Middle Urals, east of the main Uralian Fault
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Friberg, M., primary and Petrov, G. A., additional
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- 1998
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26. Rapport II. a-1. Joint sans frottement à double pompe moléculaire
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Friberg, M.
- Abstract
1) Description of the Ertaud-Holweck system. Operation under laminar and molecular conditions. Leak performance. Minimum clearance requirements. Optimum design. 2) Association of an Ertaud seal with a cylindrical gas bearing. Absence of lubricating fluid. Solution of the atmospheric seal problem. Combination of a self-centring bearing with a close-clearance seal. Possible applications in the nuclear and chemical industries., 1) Exposé du dispositif Ertaud-Holweck. Fonctionnement en régime laminaire et en régime moléculaire -performances de fuites -jeu minimum nécessaire -réalisation optimum. 2) Association d’un joint Ertaud et d’un palier à gaz cylindrique -Absence de fluide de graissage -solution du problème du joint atmosphérique -mariage d’un palier auto-centreur et d’un joint à faible jeu. Utilisations possibles dans les industries nucléaires et chimiques., Friberg M. Rapport II. a-1. Joint sans frottement à double pompe moléculaire. In: Le rôle de la mécanique des fluides dans les progrès récents des techniques. 1967.
- Published
- 1967
27. Large females lose more : sexual conflicts reduce female fecundity and directional selection on body size in the butterfly Leptidea sinapis.
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Berger, D., Friberg, M., Olofsson, M., Wiklund, C., Berger, D., Friberg, M., Olofsson, M., and Wiklund, C.
- Abstract
Part of urn:nbn:se:su:diva-7498
28. Scoring functions for transcription factor binding site prediction
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Friberg Markus, von Rohr Peter, and Gonnet Gaston
- Subjects
Computer applications to medicine. Medical informatics ,R858-859.7 ,Biology (General) ,QH301-705.5 - Abstract
Abstract Background Transcription factor binding site (TFBS) prediction is a difficult problem, which requires a good scoring function to discriminate between real binding sites and background noise. Many scoring functions have been proposed in the literature, but it is difficult to assess their relative performance, because they are implemented in different software tools using different search methods and different TFBS representations. Results Here we compare how several scoring functions perform on both real and semi-simulated data sets in a common test environment. We have also developed two new scoring functions and included them in the comparison. The data sets are from the yeast (S. cerevisiae) genome. Our new scoring function LLBG (least likely under the background model) performs best in this study. It achieves the best average rank for the correct motifs. Scoring functions based on positional bias performed quite poorly in this study. Conclusion LLBG may provide an interesting alternative to current scoring functions for TFBS prediction.
- Published
- 2005
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29. Acute airway inflammation following controlled biodiesel exhaust exposure in healthy subjects.
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Sandström T, Bosson JA, Muala A, Kabéle M, Pourazar J, Boman C, Rankin G, Mudway IS, Blomberg A, and Friberg M
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- Humans, Adult, Male, Female, Bronchoalveolar Lavage Fluid cytology, Bronchoalveolar Lavage Fluid chemistry, Bronchoalveolar Lavage Fluid immunology, Young Adult, Healthy Volunteers, Neutrophils drug effects, Neutrophils immunology, Neutrophils metabolism, Antigens, CD metabolism, Mast Cells drug effects, Mast Cells metabolism, Mast Cells immunology, Antigens, Differentiation, Myelomonocytic metabolism, Bronchi drug effects, Bronchi pathology, Macrophages drug effects, Macrophages metabolism, Bronchoscopy, Respiratory Mucosa drug effects, Respiratory Mucosa immunology, Respiratory Mucosa pathology, Respiratory Mucosa metabolism, Air Pollutants toxicity, Middle Aged, CD68 Molecule, Biofuels toxicity, Vehicle Emissions toxicity, Inhalation Exposure adverse effects
- Abstract
Background: Exposure to standard petrodiesel exhaust is linked to adverse health effects. Moreover, there is a mounting request to replace fossil-based fuels with renewable and sustainable alternatives and, therefore, rapeseed methyl ester (RME) and other biofuels have been introduced. However, recent toxicological research has indicated that biodiesel exhaust may also induce adverse health-related events., Aim: To determine whether exposure to 100% RME biodiesel (BD100) exhaust would cause an acute airway neutrophilic recruitment in humans., Methods: Fourteen healthy subjects underwent exposure to diluted BD100 exhaust and filtered air for 1-h, in a blinded, random fashion. Bronchoscopy with endobronchial mucosal biopsies, bronchial wash (BW) and bronchoalveolar lavage (BAL) was performed six hours after exposure. Differential cell counts and inflammatory markers were determined in the supernatant and biopsies were stained immunohistochemically., Results: Compared with filtered air, BD100 exhaust exposure increased bronchial mucosal endothelial P-selectin adhesion molecule expression, as well as neutrophil, mast cell and CD68 + macrophage numbers. An increased influx of neutrophils and machrophages was also seen in BW., Conclusion: Exposure to biodiesel exhaust was associated with an acute airway inflammation that appeared similar to preceding petrodiesel exposure studies. The present findings, together with the recently reported adverse cardiovascular effects after similar biodiesel exposure, indicate that biodiesel is not free of toxicity and may affect human health., Competing Interests: Declarations. Ethics approval and consent to participate: The study was performed according to the Helsinki declaration and approved at the local ethics committee at Umeå university. All participants gave their written informed consent to participate. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)
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- 2024
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30. Integration of attractive and defensive phytochemicals is unlikely to constrain chemical diversification in a perennial herb.
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Thosteman HE, Eisen K, Petrén H, Boutsi S, Pace L, Halley JM, De Moraes CM, Mescher MC, Buckley J, and Friberg M
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- Odorants analysis, Glucosinolates metabolism, Phenotype, Flowers physiology, Volatile Organic Compounds metabolism, Volatile Organic Compounds analysis, Phytochemicals analysis, Brassicaceae physiology, Plant Leaves physiology, Plant Leaves chemistry
- Abstract
Diversification of plant chemical phenotypes is typically associated with spatially and temporally variable plant-insect interactions. Floral scent is often assumed to be the target of pollinator-mediated selection, whereas foliar compounds are considered targets of antagonist-mediated selection. However, floral and vegetative phytochemicals can be biosynthetically linked and may thus evolve as integrated phenotypes. Utilizing a common garden of 28 populations of the perennial herb Arabis alpina (Brassicaceae), we investigated integration within and among floral scent compounds and foliar defense compounds (both volatile compounds and tissue-bound glucosinolates). Within floral scent volatiles, foliar volatile compounds, and glucosinolates, phytochemicals were often positively correlated, and correlations were stronger within these groups than between them. Thus, we found no evidence of integration between compound groups indicating that these are free to evolve independently. Relative to self-compatible populations, self-incompatible populations experienced stronger correlations between floral scent compounds, and a trend toward lower integration between floral scent and foliar volatiles. Our study serves as a rare test of integration of multiple, physiologically related plant traits that each are potential targets of insect-mediated selection. Our results suggest that independent evolutionary forces are likely to diversify different axes of plant chemistry without major constraints., (© 2024 The Author(s). New Phytologist © 2024 New Phytologist Foundation.)
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- 2024
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31. The challenges of recruiting never-smokers with chronic obstructive pulmonary disease from the large population-based Swedish CArdiopulmonary bioImage study (SCAPIS) cohort.
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Sönnerfors P, Jacobson PK, Andersson A, Behndig A, Bjermer L, Blomberg A, Blomqvist H, Erjefält J, Friberg M, Lamberg Lundström K, Lundborg A, Malinovschi A, Persson HL, Tufvesson E, Wheelock Å, Janson C, and Sköld CM
- Abstract
Background: A substantial proportion of individuals with COPD have never smoked, and it is implied to be more common than previously anticipated but poorly studied., Aim: To describe the process of recruitment of never-smokers with COPD from a population-based cohort ( n = 30 154)., Methods: We recruited never-smokers with COPD, aged 50-75 years, from six University Hospitals, based on: 1) post broncho-dilator forced expiratory volume in 1 second/forced vital capacity (FEV
1 /FVC) < 0.70 and 2) FEV1 50-100% of predicted value and 3) being never-smokers (self-reported). In total 862 SCAPIS participants were identified, of which 652 were reachable and agreed to a first screening by telephone. Altogether 128 (20%) were excluded due to previous smoking or declined participation. We also applied a lower limit of normal (LLN) of FEV1 /FVC (z-score<-1.64) according to the Global Lung Initiative to ensure a stricter definition of airflow obstruction., Results: Data on respiratory symptoms, health status, and medical history were collected from 492 individuals, since 32 were excluded at a second data review (declined or previous smoking), prior to the first visit. Due to not matching the required lung function criteria at a second spirometry, an additional 334 (68%) were excluded. These exclusions were by reason of: FEV1 /FVC ≥0.7 (49%), FEV1 > 100% of predicted (26%) or z-score ≥ -1,64 (24%). Finally, 154 never-smokers with COPD were included: 56 (36%) women, (mean) age 60 years, FEV1 84% of predicted, FEV1 /FVC: 0.6, z-score: -2.2, Oxygen saturation: 97% and BMI: 26.8 kg/m2 ., Conclusions: The challenges of a recruitment process of never-smokers with COPD were shown, including the importance of correct spirometry testing and strict inclusion criteria. Our findings highlight the importance of repeated spirometry assessments for improved accuracy in diagnosing COPD., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)- Published
- 2024
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32. Organisational and leadership skills towards healthy workplaces: an interview study with registered nurses in Sweden.
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Rosengren K and Friberg M
- Abstract
Background: According to shortage of registered nurses, organisational and leadership aspects grounded in person-centrered approach, are highlighted to ensure high quality of care. Therefore, it is interesting to develop knowledge regarding registered nurses working environment., Aim: The aim of the study was to investigate registered nurses' reason to end their employment at a university hospital setting (internal medicine, emergency department)., Method: Qualitative content analysis with an inductive methodological approach was used to analyse registered nurses' experiences regarding their former employment. Inclusion criteria; all nurses (n = 55) who ended employment during one year (first of July 2020-30th of June 2021) were invited, and 38 semi-structured interviews were conducted., Results: Three categories were identified: Limited organisational support, Lack of visible leadership, and Limited healthy working environment, followed by six subcategories: Longing for organisational support, Being a tile in a box, Need for professional relationship, Limitation of supportive leadership, Imbalance of work versus personal life, and Ethical stress., Conclusion: To improve registered nurses working environment and commitment to work, balance between time at work and personal life is significant. Therefore, organisational support and leadership skills grounded in a person-centred approach are crucial to develop a healthy working environment. A person-centred leadership could improve collaboration and shared decision-making in partnership with those involved, managers, nurses, and team members., (© 2024. The Author(s).)
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- 2024
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33. Development of in vitro methods to model the impact of vaginal lactobacilli on Staphylococcus aureus biofilm formation on menstrual cups as well as validation of recommended cleaning directions.
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Friberg M, Woeller K, Iberi V, Mancheno PP, Riedeman J, Bohman L, and Davis CC
- Abstract
Introduction: Menstrual cups (MC) are a reusable feminine hygiene product. A recent publication suggested that Staphylococcus aureus ( S. aureus ) biofilms can form on MCs which may lead to increased risk of menstrual Toxic Shock Syndrome (mTSS). Additionally, there is concern that buildup of residual menses may contribute to microbial growth and biofilm formation further increasing mTSS risk. Quantitative and qualitative analysis of in vitro tests were utilized to determine if S. aureus biofilm could form on MC in the presence of the keystone species Lactobacillus after 12 h of incubation. The methodology was based on a modification of an anaerobic in vitro method that harnesses the keystone species hypothesis by including a representative of vaginal lactic acid bacteria., Methods: MCs were incubated anaerobically for 12 h in Vaginal Defined Media (VDM) with the two morphologically distinct bacteria, Lactobacillus gasseri ( L. gasseri ) and S. aureus . Colony Forming Units (CFU) for each organism from the VDM broth and sonicated MC were estimated. In addition, a separate experiment was conducted where S. aureus was grown for 12 h in the absence of L. gasseri . Qualitative analysis for biofilm formation utilized micro-CT (µ-CT) and cryogenic scanning electron microscopy (Cryo-SEM)., Results: Samples collected from the media control had expected growth of both organisms after 12 h of incubation. Samples collected from VDM broth were similar to media control at the end of the 12-h study. Total S. aureus cell density on MC following sonication/rinsing was minimal. Results when using a monoculture of S. aureus demonstrated that there was a significant growth of the organism in the media control and broth as well as the sonicated cups indicating that the presence of L. gasseri was important for controlling growth and adherence of S. aureus . Few rod-shaped bacteria ( L. gasseri) and cocci ( S. aureus) could be identified on the MCs when grown in a dual species culture inoculum and no biofilm was noted via µ-CT and cryo-SEM. Additionally, efforts to model and understand the validity of the current labeled recommendations for MC cleaning in-between uses are supported., Discussion: The data support continued safe use of the Tampax® cup when used and maintained as recommended., Competing Interests: All authors are current or retired employees of The Procter & Gamble Company., (© 2023 Friberg, Woeller, Iberi, Mancheno, Riedeman, Bohman and Davis.)
- Published
- 2023
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34. Pho1a (plastid starch phosphorylase) is duplicated and essential for normal starch granule phenotype in tubers of Solanum tuberosum L.
- Author
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Sharma S, Friberg M, Vogel P, Turesson H, Olsson N, Andersson M, and Hofvander P
- Abstract
Reserve starch from seeds and tubers is a crucial plant product for human survival. Much research has been devoted to quantitative and qualitative aspects of starch synthesis and its relation to abiotic factors of importance in agriculture. Certain aspects of genetic factors and enzymes influencing carbon assimilation into starch granules remain elusive after many decades of research. Starch phosphorylase (Pho) can operate, depending on metabolic conditions, in a synthetic and degradative pathway. The plastidial form of the enzyme is one of the most highly expressed genes in potato tubers, and the encoded product is imported into starch-synthesizing amyloplasts. We identified that the genomic locus of a Pho1a-type starch phosphorylase is duplicated in potato. Our study further shows that the enzyme is of importance for a normal starch granule phenotype in tubers. Null mutants created by genome editing display rounded starch granules in an increased number that contained a reduced ratio of apparent amylose in the starch., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Sharma, Friberg, Vogel, Turesson, Olsson, Andersson and Hofvander.)
- Published
- 2023
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35. Reduced bronchoalveolar macrophage phagocytosis and cytotoxic effects after controlled short-term exposure to wood smoke in healthy humans.
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Hansson A, Rankin G, Uski O, Friberg M, Pourazar J, Lindgren R, García-López N, Boman C, Sandström T, Behndig A, and Muala A
- Subjects
- Humans, Macrophages, Phagocytosis, Inflammation chemically induced, DNA, Bronchoalveolar Lavage Fluid, Inhalation Exposure adverse effects, Smoke adverse effects, Wood
- Abstract
Background: Exposure to wood smoke has been shown to contribute to adverse respiratory health effects including airway infections, but the underlying mechanisms are unclear. A preceding study failed to confirm any acute inflammation or cell influx in bronchial wash (BW) or bronchoalveolar lavage (BAL) 24 h after wood smoke exposure but showed unexpected reductions in leukocyte numbers. The present study was performed to investigate responses at an earlier phase, regarding potential development of acute inflammation, as well as indications of cytotoxicity., Methods: In a double-blind, randomised crossover study, 14 healthy participants were exposed for 2 h to filtered air and diluted wood smoke from incomplete wood log combustion in a common wood stove with a mean particulate matter concentration of 409 µg/m
3 . Bronchoscopy with BW and BAL was performed 6 h after exposure. Differential cell counts, assessment of DNA-damage and ex vivo analysis of phagocytic function of phagocytosing BAL cells were performed. Wood smoke particles were also collected for in vitro toxicological analyses using bronchial epithelial cells (BEAS-2B) and alveolar type II-like cells (A549)., Results: Exposure to wood smoke increased BAL lactate dehydrogenase (LDH) (p = 0.04) and reduced the ex vivo alveolar macrophage phagocytic capacity (p = 0.03) and viability (p = 0.02) vs. filtered air. BAL eosinophil numbers were increased after wood smoke (p = 0.02), while other cell types were unaffected in BW and BAL. In vitro exposure to wood smoke particles confirmed increased DNA-damage, decreased metabolic activity and cell cycle disturbances., Conclusions: Exposure to wood smoke from incomplete combustion did not induce any acute airway inflammatory cell influx at 6 h, apart from eosinophils. However, there were indications of a cytotoxic reaction with increased LDH, reduced cell viability and impaired alveolar macrophage phagocytic capacity. These findings are in accordance with earlier bronchoscopy findings at 24 h and may provide evidence for the increased susceptibility to infections by biomass smoke exposure, reported in population-based studies., (© 2023. The Author(s).)- Published
- 2023
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36. Components of local adaptation and divergence in pollination efficacy in a coevolving species interaction.
- Author
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Gross K, Undin M, Thompson JN, and Friberg M
- Subjects
- Animals, Female, Pollination, Flowers, Adaptation, Physiological, Plants, Moths, Saxifragaceae
- Abstract
Selection leading to adaptation to interactions may generate rapid evolutionary feedbacks and drive diversification of species interactions. The challenge is to understand how the many traits of interacting species combine to shape local adaptation in ways directly or indirectly resulting in diversification. We used the well-studied interactions between Lithophragma plants (Saxifragaceae) and Greya moths (Prodoxidae) to evaluate how plants and moths together contributed to local divergence in pollination efficacy. Specifically, we studied L. bolanderi and its two specialized Greya moth pollinators in two contrasting environments in the Sierra Nevada in California. Both moths pollinate L. bolanderi during nectaring, one of them-G. politella-also while ovipositing through the floral corolla into the ovary. First, field surveys of floral visitors and the presence of G. politella eggs and larvae in developing capsules showed that one population was visited only by G. politella and few other pollinators, whereas the other was visited by both Greya species and other pollinators. Second, L. bolanderi in these two natural populations differed in several floral traits putatively important for pollination efficacy. Third, laboratory experiments with greenhouse-grown plants and field-collected moths showed that L. bolanderi was more efficiently pollinated by local compared to nonlocal nectaring moths of both species. Pollination efficacy of ovipositing G. politella was also higher for local moths for the L. bolanderi population, which relies more heavily on this species in nature. Finally, time-lapse photography in the laboratory showed that G. politella from different populations differed in oviposition behavior, suggesting the potential for local adaptation also among Greya populations. Collectively, our results are a rare example of components of local adaptation contributing to divergence in pollination efficacy in a coevolving interaction and, thus, provide insights into how geographic mosaics of coevolution may lead to coevolutionary diversification in species interactions., (© 2023 The Authors. Ecology published by Wiley Periodicals LLC on behalf of The Ecological Society of America.)
- Published
- 2023
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37. Analysis of trait-performance-fitness relationships reveals pollinator-mediated selection on orchid pollination traits.
- Author
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Rodríguez-Otero C, Hedrén M, Friberg M, and Opedal ØH
- Subjects
- Reproduction, Pollen, Phenotype, Pollination, Orchidaceae
- Abstract
Premise: The role of pollinators in evolutionary floral divergence has spurred substantial effort into measuring pollinator-mediated phenotypic selection and its variation in space and time. For such estimates, the fitness consequences of pollination processes must be separated from other factors affecting fitness., Methods: We built a fitness function linking phenotypic traits of food-deceptive orchids to female reproductive success by including pollinator visitation and pollen deposition as intermediate performance components and used the fitness function to estimate the strength of pollinator-mediated selection through female reproductive success. We also quantified male performance as pollinarium removal and assessed similarity in trait effects on male and female performance., Results: The proportion of plants visited at least once by an effective pollinator was moderate to high, ranging from 53.7% to 85.1%. Tall, many-flowered plants were often more likely to be visited and pollinated. Given effective pollination, pollen deposition onto stigmas tended to be more likely for taller plants. Pollen deposition further depended on traits affecting the physical fit of pollinators to flowers (flower size, spur length), though the exact relationships varied in time and space. Using the fitness function to assess pollinator-mediated selection through female reproductive success acting on multiple traits, we found that selection varied detectably among taxa after accounting for sampling uncertainty. Across taxa, selection on most traits was stronger on average and more variable when pollination was less reliable., Conclusions: These results support pollination-related trait-performance-fitness relationships and thus pollinator-mediated selection on traits functionally involved in the pollination process., (© 2023 The Authors. American Journal of Botany published by Wiley Periodicals LLC on behalf of Botanical Society of America.)
- Published
- 2023
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38. The Effects of Stress on Tourniquet Application and CPR Performance in Layperson and Professional Civilian Populations.
- Author
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Friberg M, Jonson CO, Jaeger V, and Prytz E
- Subjects
- Humans, First Aid, Hemorrhage prevention & control, Task Performance and Analysis, Tourniquets, Cardiopulmonary Resuscitation
- Abstract
Objective: The purpose of this study was to compare laypeople's and professional first responders' ability to perform tourniquet application and cardiopulmonary resuscitation (CPR) during calm and stressful circumstances., Background: Life-threatening bleeding is a major cause of death that could be prevented by fast and appropriate first aid interventions. Therefore, laypeople are now being trained in bleeding control skills, transforming them from bystanders to immediate responders. However, critics have questioned whether laypeople are able to perform during more stressful conditions., Method: Twenty-four laypersons and 31 professional first responders were tested in two conditions: a calm classroom scenario and a stressful scenario consisting of paintball fire and physical exertion. Stress and workload were assessed along with task performance., Results: The experimental manipulation was successful in terms of eliciting stress reactions. Tourniquet application performance did not decline in the stressful condition, but some aspects of CPR performance did for both groups. First responders experienced higher task engagement and lower distress, worry and workload than the laypeople in both the calm and stressful conditions., Conclusion: Stress did not affect first responders and laypeople differently in terms of performance effects. Stress should therefore not be considered a major obstacle for teaching bleeding control skills to laypeople., Application: Tourniquet application can be taught to laypeople in a short amount of time, and they can perform this skill during stress in controlled settings. Concerns about laypeople's ability to perform under stress should not exclude bleeding control skills from first aid courses for civilian laypeople.
- Published
- 2023
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39. Differences in mating system and predicted parental conflict affect post-pollination reproductive isolation in a flowering plant.
- Author
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Petrén H, Thosteman H, Stift M, Toräng P, Ågren J, and Friberg M
- Subjects
- Reproductive Isolation, Crosses, Genetic, Reproduction, Seeds genetics, Flowers genetics, Pollination, Magnoliopsida genetics
- Abstract
Mating system shifts from outcrossing to selfing are frequent in plant evolution. Relative to outcrossing, selfing is associated with reduced parental conflict over seed provisioning, which may result in postzygotic, asymmetric, reproductive isolation in crosses between populations of different mating systems. To test the hypothesis that post-pollination reproductive isolation between populations increases with increasing differences in mating system and predicted parental conflict, we performed a crossing experiment involving all combinations of three self-compatible populations (with low outcrossing rates), and three self-incompatible populations (with high outcrossing rates) of the arctic-alpine herb Arabis alpina, assessing fitness-related seed and plant traits of the progeny. Predicted levels of parental conflict ("genome strength") were quantified based on strength of self-incompatibility and estimates of outcrossing rates. Crosses between self-compatible and self-incompatible populations yielded very small seeds of low viability, resulting in strong reproductive isolation. In 14 of 15 reciprocal between-population crosses, seeds were heavier when the paternal plant had the stronger genome, and seed mass differences between cross directions increased with an increased difference in parental conflict. Overall, our results suggest that, when sufficiently large, differences in mating system and hence in expected parental conflict may result in strong post-pollination reproductive barriers contributing to speciation., (© The Author(s) 2023. Published by Oxford University Press on behalf of The Society for the Study of Evolution (SSE).)
- Published
- 2023
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40. Extensive pollinator sharing does not promote character displacement in two orchid congeners.
- Author
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Joffard N, Olofsson C, Friberg M, and Sletvold N
- Subjects
- Odorants, Pollen, Sympatry, Flowers, Pollination
- Abstract
Pollinator sharing between close relatives can be costly and can promote pollination niche partitioning and floral divergence. This should be reflected by a higher species divergence in sympatry than in allopatry. We tested this hypothesis in two orchid congeners with overlapping distributions and flowering times. We characterized floral traits and pollination niches and quantified pollen limitation in 15 pure and mixed populations, and we measured phenotypic selection on floral traits and performed controlled crosses in one mixed site. Most floral traits differed between species, yet pollinator sharing was extensive. Only the timing of scent emission diverged more in mixed sites than in pure sites, and this was not mirrored by the timing of pollinator visitation. We did not detect divergent selection on floral traits. Seed production was pollen limited in most populations but not more severely in mixed sites than in pure sites. Interspecific crosses produced the same or a higher proportion of viable seeds than intraspecific crosses. The two orchid species attract the same pollinator species despite showing divergent floral traits. However, this does not promote character displacement, implying a low cost of pollinator sharing. Our results highlight the importance of characterizing both traits and ecological niches in character displacement studies., (© 2022 The Authors. Evolution © 2022 The Society for the Study of Evolution.)
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- 2022
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41. Genomic Signatures of Sexual Selection on Pollen-Expressed Genes in Arabis alpina.
- Author
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Gutiérrez-Valencia J, Fracassetti M, Horvath R, Laenen B, Désamore A, Drouzas AD, Friberg M, Kolář F, and Slotte T
- Subjects
- Genomics, Pollen genetics, Self-Fertilization, Sexual Selection, Arabis
- Abstract
Fertilization in angiosperms involves the germination of pollen on the stigma, followed by the extrusion of a pollen tube that elongates through the style and delivers two sperm cells to the embryo sac. Sexual selection could occur throughout this process when male gametophytes compete for fertilization. The strength of sexual selection during pollen competition should be affected by the number of genotypes deposited on the stigma. As increased self-fertilization reduces the number of mating partners, and the genetic diversity and heterozygosity of populations, it should thereby reduce the intensity of sexual selection during pollen competition. Despite the prevalence of mating system shifts, few studies have directly compared the molecular signatures of sexual selection during pollen competition in populations with different mating systems. Here we analyzed whole-genome sequences from natural populations of Arabis alpina, a species showing mating system variation across its distribution, to test whether shifts from cross- to self-fertilization result in molecular signatures consistent with sexual selection on genes involved in pollen competition. We found evidence for efficient purifying selection on genes expressed in vegetative pollen, and overall weaker selection on sperm-expressed genes. This pattern was robust when controlling for gene expression level and specificity. In agreement with the expectation that sexual selection intensifies under cross-fertilization, we found that the efficacy of purifying selection on male gametophyte-expressed genes was significantly stronger in genetically more diverse and outbred populations. Our results show that intra-sexual competition shapes the evolution of pollen-expressed genes, and that its strength fades with increasing self-fertilization rates., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.)
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- 2022
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42. Is There a Dose-Response Relationship between Acute Physical Activity and Sleep Length? A Longitudinal Study with Children and Adolescents Living in Sweden.
- Author
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Nordman A, Friberg M, and Forsell Y
- Abstract
A declining physical activity (PA) and sleep in children and adolescents have been observed during the previous decades. PA could benefit sleep, but the findings are mixed. The aim of the present study was to examine if there is a dose-response relationship between time spent in acute moderate and vigorous physical activity (MVPA) and sleep length in children and adolescents. Additional aims were to examine if the sleep length is higher for children and adolescents who conduct at least an average of 60 min in MVPA/day and to study differences between sex and school years. The study population consists of 262 participants in school year 5 (aged 11 years), 7 (aged 13 years), and 9 (aged 15 years). Accelerometers measured MVPA while sleep diaries measured sleep length. A linear and longitudinal mixed effect linear regression was conducted to study the primary aim. The secondary aims were studied with linear regressions. Included confounders were sex, school year, school stress, screen time, menstruation onset, family household economy, and health status. A stratified regression for sex and school year was conducted. The linear regression showed no statistically significant findings in the crude or adjusted model. The stratified linear regression found a significant positive association for girls but a negative association for school year 5. No associations were found in the longitudinal regression or when comparing sleep length for participants that did and did not spend an average of at least 60 min in MVPA/day. A dose-response relationship was found in the stratified linear regression, implying a possible weak association. The statistically non-significant differences between participants that did and did not spend an average of at least 60 min in MVPA/day implies that spending an average of at least 60 min in MVPA/day may not be associated with a higher mean sleep length.
- Published
- 2021
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43. Laypeople perception and interpretation of simulated life-threatening bleeding: a controlled experimental study.
- Author
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Prytz E, Phillips R, Lönnqvist S, Friberg M, and Jonson CO
- Subjects
- Adolescent, Adult, Female, Humans, Male, Middle Aged, Patient Simulation, Research Design, Young Adult, First Aid, Hemorrhage therapy, Tourniquets
- Abstract
Introduction: First aid performed by immediate responders can be the difference between life and death in the case of trauma with massive bleeding. To develop effective training programs to teach bleeding control to laypersons, it is important to be aware of beliefs and misconceptions people hold on bleeding and severity of bleeding situations., Method: A controlled study was conducted in which 175 American college students viewed 78 video clips of simulated bleeding injuries. The volume of blood present (between 0 and 1900 ml), rate of blood flow, and victim gender were systematically varied within participants. Participants were asked to rate injury severity, indicate the appropriate first aid action, and estimate the amount of time until death for the victim., Results: Though the Stop the Bleed® campaign recommends training laypeople to treat 165 ml of blood loss as life threatening, participants largely rated this volume of blood loss as minimal, mild, or moderate and estimated that the victim had just under one hour to live. Increased blood loss was associated with increased recommendations to use a tourniquet. However, in the 1900 ml conditions, participants still estimated that victims had around 22 minutes to live and approximately 15% recommended direct pressure as the intervention. Severity ratings and recommendations to use a tourniquet were also higher for the male victim than the female victim., Conclusions: Injury classification, intervention selection, and time to death-estimations revealed that training interventions should connect classifications of blood loss to appropriate action and focus on perceptions of how much time one has to respond to a bleeding. The study also revealed a gender related bias in terms of injury classification and first aid recommendations. Bleeding control training programs can be designed to address identified biases and misconceptions while building on existing knowledge and commonly used terminology., (© 2021. The Author(s).)
- Published
- 2021
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44. Evolution of floral scent in relation to self-incompatibility and capacity for autonomous self-pollination in the perennial herb Arabis alpina.
- Author
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Petrén H, Toräng P, Ågren J, and Friberg M
- Subjects
- Flowers, France, Greece, Italy, Odorants, Reproduction, Spain, Arabis, Pollination
- Abstract
Background and Aims: The transition from outcrossing to selfing is a frequent evolutionary shift in flowering plants and is predicted to result in reduced allocation to pollinator attraction if plants can self-pollinate autonomously. The evolution of selfing is associated with reduced visual floral signalling in many systems, but effects on floral scent have received less attention. We compared multiple populations of the arctic-alpine herb Arabis alpina (Brassicaceae), and asked whether the transition from self-incompatibility to self-compatibility has been associated with reduced visual and chemical floral signalling. We further examined whether floral signalling differ between self-compatible populations with low and high capacity for autonomous self-pollination, as would be expected if benefits of signalling decrease with reduced dependence on pollinators for pollen transfer., Methods: In a common garden we documented flower size and floral scent emission rate and composition in eight self-compatible and nine self-incompatible A. alpina populations. These included self-compatible Scandinavian populations with high capacity for autonomous self-pollination, self-compatible populations with low capacity for autonomous self-pollination from France and Spain, and self-incompatible populations from Italy and Greece., Key Results: The self-compatible populations produced smaller and less scented flowers than the self-incompatible populations. However, flower size and scent emission rate did not differ between self-compatible populations with high and low capacity for autonomous self-pollination. Floral scent composition differed between self-compatible and self-incompatible populations, but also varied substantially among populations within the two categories., Conclusions: Our study demonstrates extensive variation in floral scent among populations of a geographically widespread species. Contrary to expectation, floral signalling did not differ between self-compatible populations with high and low capacity for autonomous self-pollination, indicating that dependence on pollinator attraction can only partly explain variation in floral signalling. Additional variation may reflect adaptation to other aspects of local environments, genetic drift, or a combination of these processes., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Annals of Botany Company.)
- Published
- 2021
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45. Innate preference hierarchies coupled with adult experience, rather than larval imprinting or transgenerational acclimation, determine host plant use in Pieris rapae .
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Petrén H, Gloder G, Posledovich D, Wiklund C, and Friberg M
- Abstract
The evolution of host range drives diversification in phytophagous insects, and understanding the female oviposition choices is pivotal for understanding host specialization. One controversial mechanism for female host choice is Hopkins' host selection principle, where females are predicted to increase their preference for the host species they were feeding upon as larvae. A recent hypothesis posits that such larval imprinting is especially adaptive in combination with anticipatory transgenerational acclimation, so that females both allocate and adapt their offspring to their future host. We study the butterfly Pieris rapae , for which previous evidence suggests that females prefer to oviposit on host individuals of similar nitrogen content as the plant they were feeding upon as larvae, and where the offspring show higher performance on the mother's host type. We test the hypothesis that larval experience and anticipatory transgenerational effects influence female host plant acceptance (no-choice) and preference (choice) of two host plant species ( Barbarea vulgaris and Berteroa incana ) of varying nitrogen content. We then test the offspring performance on these hosts. We found no evidence of larval imprinting affecting female decision-making during oviposition, but that an adult female experience of egg laying in no-choice trials on the less-preferred host Be. incana slightly increased the P. rapae propensity to oviposit on Be. incana in subsequent choice trials. We found no transgenerational effects on female host acceptance or preference, but negative transgenerational effects on larval performance, because the offspring of P. rapae females that had developed on Be. incana as larvae grew slower on both hosts, and especially on Be. incana . Our results suggest that among host species, preferences are guided by hard-wired preference hierarchies linked to species-specific host traits and less affected by larval experience or transgenerational effects, which may be more important for females evaluating different host individuals of the same species., Competing Interests: The authors declare that they have no conflict of interest., (© 2020 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)
- Published
- 2020
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46. Visual estimates of blood loss by medical laypeople: Effects of blood loss volume, victim gender, and perspective.
- Author
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Phillips R, Friberg M, Lantz Cronqvist M, Jonson CO, and Prytz E
- Subjects
- Adolescent, Adult, Female, Humans, Male, Perception, Sex Factors, Health Knowledge, Attitudes, Practice, Hemorrhage psychology
- Abstract
A severe hemorrhage can result in death within minutes, before professional first responders have time to arrive. Thus, intervention by bystanders, who may lack medical training, may be necessary to save a victim's life in situations with bleeding injuries. Proper intervention requires that bystanders accurately assess the severity of the injury and respond appropriately. As many bystanders lack tools and training, they are limited in terms of the information they can use in their evaluative process. In hemorrhage situations, visible blood loss may serve as a dominant cue to action. Therefore, understanding how medically untrained bystanders (i.e., laypeople) perceive hemorrhage is important. The purpose of the current study was to investigate the ability of laypeople to visually assess blood loss and to examine factors that may impact accuracy and the classification of injury severity. A total of 125 laypeople watched 78 short videos each of individuals experiencing a hemorrhage. Victim gender, volume of blood lost, and camera perspective were systematically manipulated in the videos. The results revealed that laypeople overestimated small volumes of blood loss (from 50 to 200 ml), and underestimated larger volumes (from 400 to 1900 ml). Larger volumes of blood loss were associated with larger estimation errors. Further, blood loss was underestimated more for female victims than male victims and their hemorrhages were less likely to be classified as life-threatening. These results have implications for training and intervention design., Competing Interests: I have read the journal's policy and the authors of this manuscript have the following competing interests: CJ is a member of the Red Cross; EP and CJ have filed a patent application for a Tourniquet Training Device (application number 20200170649). This does not alter our adherence to PLOS ONE policies on sharing data and materials.
- Published
- 2020
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47. Incomplete Sterility of Chromosomal Hybrids: Implications for Karyotype Evolution and Homoploid Hybrid Speciation.
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Lukhtanov VA, Dincă V, Friberg M, Vila R, and Wiklund C
- 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., (Copyright © 2020 Lukhtanov, Dincă, Friberg, Vila and Wiklund.)
- Published
- 2020
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48. School-related physical activity interventions and mental health among children: a systematic review and meta-analysis.
- Author
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Andermo S, Hallgren M, Nguyen TT, Jonsson S, Petersen S, Friberg M, Romqvist A, Stubbs B, and Elinder LS
- Abstract
Background: Low levels of physical activity, sedentary behaviour and mental health problems are issues that have received considerable attention in the last decade. The aim of this systematic review and meta-analysis was to investigate effects of interventions targeting school-related physical activity or sedentary behaviour on mental health in children and adolescents and to identify the features of effective interventions., Methods: Scientific articles published between January 2009 and October 2019 fulfilling the following criteria were included: general populations of children and adolescents between age 4 and 19, all types of school-related efforts to promote physical activity or reduce sedentary behaviour. Study selection, data extraction and quality assessment were done by at least two authors independently of each other. Data were analysed with a random effects meta-analysis and by narrative moderator analyses., Results: The literature search resulted in 10265 unique articles. Thirty-one articles, describing 30 interventions, were finally included. Eleven relevant outcomes were identified: health-related quality of life, well-being, self-esteem and self-worth, resilience, positive effect, positive mental health, anxiety, depression, emotional problems, negative effect and internalising mental health problems. There was a significant beneficial effect of school-related physical activity interventions on resilience (Hedges' g = 0.748, 95% CI = 0.326; 1.170, p = 0.001), positive mental health (Hedges' g = 0.405, 95% CI = 0.208; 0.603, p = < 0.001), well-being (Hedges' g = 0.877, 95% CI = 0.356; 1.398, p = < 0.001) and anxiety (Hedges' g = 0.347, 95% CI = 0.072; 0.623, p = 0.013). Heterogeneity was moderate to high (I
2 = 59-98%) between studies for all outcomes except positive effect, where heterogeneity was low (I2 = 2%). The narrative moderator analyses of outcomes based on 10 or more studies showed that age of the children moderated the effect of the intervention on internalising mental health problems. Interventions in younger children showed a significantly negative or no effect on internalising mental health problems while those in older children showed a significant positive or no effect. Moreover, studies with a high implementation reach showed a significant negative or no effect while those with a low level of implementation showed no or a positive effect. No signs of effect moderation were found for self-esteem, well-being or positive mental health. Risk of publication bias was evident for several outcomes, but adjustment did not change the results., Conclusions: School-related physical activity interventions may reduce anxiety, increase resilience, improve well-being and increase positive mental health in children and adolescents. Considering the positive effects of physical activity on health in general, these findings may reinforce school-based initiatives to increase physical activity. However, the studies show considerable heterogeneity. The results should therefore be interpreted with caution. Future studies should report on implementation factors and more clearly describe the activities of the control group and whether the activity is added to or replacing ordinary physical education lessons in order to aid interpretation of results., Trial Registration: PROSPERO, CRD42018086757.- Published
- 2020
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49. Ten Lessons for Good Practice for the INHERIT Triple Win: Health, Equity, and Environmental Sustainability.
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Bell R, Khan M, Romeo-Velilla M, Stegeman I, Godfrey A, Taylor T, Morris G, Staatsen B, van der Vliet N, Kruize H, Anthun KS, Lillefjell M, Espnes GA, Chiabai A, de Jalón SG, Quiroga S, Martinez-Juarez P, Máca V, Zvěřinová I, Ščasný M, Marques S, Craveiro D, Westerink J, Spelt H, Karnaki P, Strube R, Merritt AS, Friberg M, Bélorgey N, Vos M, Gjorgjev D, Upelniece I, and Costongs C
- Subjects
- Europe, Humans, Climate Change, Ecosystem, Health Equity economics, Health Status, Housing economics, Socioeconomic Factors
- Abstract
The world's challenges of climate change, damage to ecosystems, and social and health inequalities require changes in human behaviours at every level of organisation, among governments, business, communities, and individuals. An important question is how behaviour change can be enabled and supported at the scale and speed required. The research reported in this paper describes important lessons for good practice in changing contexts to modify behaviours for a triple win for health, equity and environmental sustainability. Authors synthesised learning from qualitative, quantitative and cost benefit evaluations of 15 case studies conducted in 12 countries in Europe. The case studies address ways of living (green spaces and energy efficient housing), moving (active transport) and consuming (healthy and sustainable diets) that support the triple win. Ten lessons for good practice were identified. These include bringing a triple win mindset to policy and practice in planning interventions, with potential to improve environmental sustainability, health and equity at the same time. The lessons for good practice are intended to support governmental and non-governmental actors, practitioners and researchers planning to work across sectors to achieve mutual benefits for health and environmental sustainability and in particular to benefit poorer and more socio-economically disadvantaged groups., Competing Interests: The authors declare no conflict of interest. The funding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.
- Published
- 2019
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50. Dissecting the Effects of Selection and Mutation on Genetic Diversity in Three Wood White (Leptidea) Butterfly Species.
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Talla V, Soler L, Kawakami T, Dincă V, Vila R, Friberg M, Wiklund C, and Backström N
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- Animals, Base Composition, Genetic Variation, Molecular Sequence Annotation, Recombination, Genetic, Butterflies genetics, Mutation, Selection, Genetic
- Abstract
The relative role of natural selection and genetic drift in evolution is a major topic of debate in evolutionary biology. Most knowledge spring from a small group of organisms and originate from before it was possible to generate genome-wide data on genetic variation. Hence, it is necessary to extend to a larger number of taxonomic groups, descriptive and hypothesis-based research aiming at understanding the proximate and ultimate mechanisms underlying both levels of genetic polymorphism and the efficiency of natural selection. In this study, we used data from 60 whole-genome resequenced individuals of three cryptic butterfly species (Leptidea sp.), together with novel gene annotation information and population recombination data. We characterized the overall prevalence of natural selection and investigated the effects of mutation and linked selection on regional variation in nucleotide diversity. Our analyses showed that genome-wide diversity and rate of adaptive substitutions were comparatively low, whereas nonsynonymous to synonymous polymorphism and substitution levels were comparatively high in Leptidea, suggesting small long-term effective population sizes. Still, negative selection on linked sites (background selection) has resulted in reduced nucleotide diversity in regions with relatively high gene density and low recombination rate. We also found a significant effect of mutation rate variation on levels of polymorphism. Finally, there were considerable population differences in levels of genetic diversity and pervasiveness of selection against slightly deleterious alleles, in line with expectations from differences in estimated effective population sizes., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.)
- Published
- 2019
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