| 1. |
- Bamia, Christina, et al.
(author)
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Dietary patterns and survival of older Europeans : the EPIC-Elderly Study (European Prospective Investigation into Cancer and Nutrition)
- 2007
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In: Public Health Nutrition. - : Cambridge University Press. - 1368-9800 .- 1475-2727. ; 10:6, s. 590-598
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Journal article (peer-reviewed)abstract
- Objective: To investigate the association of a posteriori dietary patterns with overall survival of older Europeans.Design and setting: This is a multi-centre cohort study. Cox regression analysis was used to investigate the association of the prevailing, a posteriori-derived, plant-based dietary pattern with all-cause mortality in a population of subjects who were 60 years or older at recruitment to the European Prospective Investigation into Cancer and Nutrition (EPIC-Elderly cohort). Analyses controlled for all known potential risk factors.Subjects: In total, 74 607 men and women, 60 years or older at enrolment and without previous coronary heart disease, stroke or cancer, with complete information about dietary intakes and potentially confounding variables, and with known survival status as of December 2003, were included in the analysis.Results: An increase in the score which measures the adherence to the plant-based diet was associated with a lower overall mortality, a one standard deviation increment corresponding to a statistically significant reduction of 14% (95% confidence interval 5–23%). In country-specific analyses the apparent association was stronger in Greece, Spain, Denmark and The Netherlands, and absent in the UK and Germany.Conclusions: Greater adherence to the plant-based diet that was defined a posteriori in this population of European elders is associated with lower all-cause mortality. This dietary score is moderately positively correlated with the Modified Mediterranean Diet Score that has been constructed a priori and was also shown to be beneficial for the survival of the same EPIC-Elderly cohort.
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| 2. |
- Bjursten, Henrik, et al.
(author)
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Characteristics and Outcomes of Patients Receiving a Second Rescue Valve During Transcatheter Aortic Valve Implantation
- 2024
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In: Structural Heart. - : Elsevier. - 2474-8706 .- 2474-8714. ; 8:2
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Journal article (peer-reviewed)abstract
- Background: Transcatheter aortic valve implantation (TAVI) has become a safe procedure. However, complications occur, including uncommon complications such as valve malposition, which requires the implantation of an additional rescue valve (rescue-AV). The aim was to study the occurrence and outcomes of rescue-AV in a nationwide registry. Methods: The Swedish national TAVI registry was used as the primary data source, where all 6706 TAVI procedures from 2016 to 2021 were retrieved. Nontransfemoral access and planned valve-in-valve were excluded. In total, 79 patients were identified as having had a rescue-AV, and additional detailed data were collected for these patients. This dataset was analyzed for any characteristics that could predispose patients to a rescue-AV. The outcome of patients receiving rescue-AV also was studied. Results: Of the 5948 patients in the study, 1.3% had a rescue-AV. There were few differences between patients receiving 1 valve and rescue-AV patients. For patients receiving a rescue-AV, the 30-day mortality was 15.2% compared to 1.6% in the control group. A poor outcome after rescue-AV was often associated with a second complication; for example, stroke, need for emergency surgery, or heart failure. Among the patients with rescue-AV who survived at least 30 days, landmark analyses showed similar survival rates compared to the control group. Conclusions: Among TAVI patients in a nationwide register, rescue-AV occurred in 1.3% of patients. The 30-day mortality in patients receiving rescue-AV was high, but long-term outcome among 30-day survivors was similar to the control group.
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| 3. |
- Brännström, Åke, et al.
(author)
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Modelling the ecology and evolution of communities : a review of past achievements, current efforts, and future promises
- 2012
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In: Evolutionary Ecology Research. - 1522-0613 .- 1937-3791. ; 14:5, s. 601-625
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Journal article (peer-reviewed)abstract
- Background: The complexity and dynamical nature of community interactions make modelling a useful tool for understanding how communities develop over time and how they respond to external perturbations. Large community-evolution models (LCEMs) are particularly promising, since they can address both ecological and evolutionary questions, and can give rise to richly structured and diverse model communities.Questions: Which types of models have been used to study community structure and what are their key features and limitations? How do adaptations and/or invasions affect community formation? Which mechanisms promote diverse and stable communities? What are the implications of LCEMs for management and conservation? What are the key challenges for future research?Models considered: Static models of community structure, demographic community models, and small and large community-evolution models.Conclusions: Large community-evolution models encompass a variety of modelled traits and interactions, demographic dynamics, and evolutionary dynamics. They are able to reproduce empirical community structures. They have already generated new insights, such as the dual role of competition, which limits diversity through competitive exclusion yet facilitates diversity through speciation. Other critical factors determining eventual community structure are the shape of trade-off functions, inclusion of adaptive foraging, and energy availability. A particularly interesting feature of LCEMs is that these models not only help to contrast outcomes of community formation via species assembly with those of community formation via gradual evolution and speciation, but that they can furthermore unify the underlying invasion processes and evolutionary processes into a single framework.
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| 4. |
- Brännström, Åke, et al.
(author)
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The Hitchhiker's guide to adaptive dynamics
- 2013
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In: Games. - : MDPI AG. - 2073-4336. ; 4:3, s. 304-328
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Journal article (peer-reviewed)abstract
- Adaptive dynamics is a mathematical framework for studying evolution. It extends evolutionary game theory to account for more realistic ecological dynamics and it can incorporate both frequency- and density-dependent selection. This is a practical guide to adaptive dynamics that aims to illustrate how the methodology can be applied to the study of specific systems. The theory is presented in detail for a single, monomorphic, asexually reproducing population. We explain the necessary terminology to understand the basic arguments in models based on adaptive dynamics, including invasion fitness, the selection gradient, pairwise invasibility plots (PIP), evolutionarily singular strategies, and the canonical equation. The presentation is supported with a worked-out example of evolution of arrival times in migratory birds. We show how the adaptive dynamics methodology can be extended to study evolution in polymorphic populations using trait evolution plots (TEPs). We give an overview of literature that generalises adaptive dynamics techniques to other scenarios, such as sexual, diploid populations, and spatially-structured populations. We conclude by discussing how adaptive dynamics relates to evolutionary game theory and how adaptive-dynamics techniques can be used in speciation research.
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| 5. |
- Buhlin, Kare, et al.
(author)
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Association of periodontitis with persistent, pro-atherogenic antibody responses
- 2015
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In: Journal of Clinical Periodontology. - : Wiley-Blackwell. - 0303-6979 .- 1600-051X. ; 42:11, s. 1006-1014
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Journal article (peer-reviewed)abstract
- AIM: To study antibody responses associated with molecular mimicry in periodontitis.MATERIAL AND METHODS: Fifty-four periodontitis cases (mean age 54.0 years) and 44 controls (53.6 years) were examined, after which cases received periodontal treatment. Established immunoassays were used to analyse levels of antibodies against two pathogens, Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg), heat shock proteins (Hsp), Hsp60, Hsp65, and Hsp70, and epitopes of oxidized low density lipoprotein (oxLDL) (CuOx-LDL and MDA-LDL) in plasma samples that were collected at baseline, after 3 (n=48) and 6 (n=30) months.RESULTS: When age, sex, smoking habit, and the number of teeth were considered in multivariate logistic regressions, Aa and Pg IgG, Hsp65-IgA, CuOx-LDL-IgG and -IgM and MDA-LDL-IgG antibody levels were associated with periodontitis, whereas Hsp60-IgG2 antibody levels were inversely associated. The Aa antibody levels significantly correlated with the levels of IgA antibodies to Hsp65 and Hsp70, and both OxLDL IgA-antibody levels. The levels of antibodies to Pg correlated with IgG antibodies to Hsp60, Hsp70 and both oxLDL antibody epitopes. None of the antibody levels changed significantly after treatment.CONCLUSIONS: Periodontitis is associated with persistently high levels of circulating antibodies that are reactive with pathogen- and host-derived antigens.
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| 6. |
- Cantwell-Jones, Aoife, et al.
(author)
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Mapping trait versus species turnover reveals spatiotemporal variation in functional redundancy and network robustness in a plant-pollinator community
- 2023
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In: Functional Ecology. - : John Wiley & Sons. - 0269-8463 .- 1365-2435. ; 37:3, s. 748-762
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Journal article (peer-reviewed)abstract
- Functional overlap among species (redundancy) is considered important in shaping competitive and mutualistic interactions that determine how communities respond to environmental change. Most studies view functional redundancy as static, yet traits within species—which ultimately shape functional redundancy—can vary over seasonal or spatial gradients. We therefore have limited understanding of how trait turnover within and between species could lead to changes in functional redundancy or how loss of traits could differentially impact mutualistic interactions depending on where and when the interactions occur in space and time. Using an Arctic bumblebee community as a case study, and 1277 individual measures from 14 species over three annual seasons, we quantified how inter- and intraspecific body-size turnover compared to species turnover with elevation and over the season. Coupling every individual and their trait with a plant visitation, we investigated how grouping individuals by a morphological trait or by species identity altered our assessment of network structure and how this differed in space and time. Finally, we tested how the sensitivity of the network in space and time differed when simulating extinction of nodes representing either morphological trait similarity or traditional species groups. This allowed us to explore the degree to which trait-based groups increase or decrease interaction redundancy relative to species-based nodes. We found that (i) groups of taxonomically and morphologically similar bees turn over in space and time independently from each other, with trait turnover being larger over the season; (ii) networks composed of nodes representing species versus morphologically similar bees were structured differently; and (iii) simulated loss of bee trait groups caused faster coextinction of bumblebee species and flowering plants than when bee taxonomic groups were lost. Crucially, the magnitude of these effects varied in space and time, highlighting the importance of considering spatiotemporal context when studying the relative importance of taxonomic and trait contributions to interaction network architecture. Our finding that functional redundancy varies spatiotemporally demonstrates how considering the traits of individuals within networks is needed to understand the impacts of environmental variation and extinction on ecosystem functioning and resilience. Read the free Plain Language Summary for this article on the Journal blog.
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| 7. |
- Franklin, Oskar, et al.
(author)
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Modeling carbon allocation in trees : a search for principles
- 2012
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In: Tree Physiology. - : Oxford University Press (OUP). - 0829-318X .- 1758-4469. ; 32:6, s. 648-666
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Research review (peer-reviewed)abstract
- We review approaches to predicting carbon and nitrogen allocation in forest models in terms of their underlying assumptions and their resulting strengths and limitations. Empirical and allometric methods are easily developed and computationally efficient, but lack the power of evolution-based approaches to explain and predict multifaceted effects of environmental variability and climate change. In evolution-based methods, allocation is usually determined by maximization of a fitness proxy, either in a fixed environment, which we call optimal response (OR) models, or including the feedback of an individual's strategy on its environment (game-theoretical optimization, GTO). Optimal response models can predict allocation in single trees and stands when there is significant competition only for one resource. Game-theoretical optimization can be used to account for additional dimensions of competition, e.g., when strong root competition boosts root allocation at the expense of wood production. However, we demonstrate that an OR model predicts similar allocation to a GTO model under the root-competitive conditions reported in free-air carbon dioxide enrichment (FACE) experiments. The most evolutionarily realistic approach is adaptive dynamics (AD) where the allocation strategy arises from eco-evolutionary dynamics of populations instead of a fitness proxy. We also discuss emerging entropy-based approaches that offer an alternative thermodynamic perspective on allocation, in which fitness proxies are replaced by entropy or entropy production. To help develop allocation models further, the value of wide-ranging datasets, such as FLUXNET, could be greatly enhanced by ancillary measurements of driving variables, such as water and soil nitrogen availability.
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| 8. |
- Johansson, Emil, et al.
(author)
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Hierarchical Clustering and Trajectory Analyses Reveal Viremia-Independent B-Cell Perturbations in HIV-2 Infection
- 2022
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In: Cells. - : MDPI. - 2073-4409. ; 11:19
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Journal article (peer-reviewed)abstract
- Time to AIDS in HIV-2 infection is approximately twice as long compared to in HIV-1 infection. Despite reduced viremia, HIV-2-infected individuals display signs of chronic immune activation. In HIV-1-infected individuals, B-cell hyperactivation is driven by continuous antigen exposure. However, the contribution of viremia to B-cell perturbations in HIV-2-infected individuals remains largely unexplored. Here, we used polychromatic flow cytometry, consensus hierarchical clustering and pseudotime trajectory inference to characterize B-cells in HIV-1- or HIV-2-infected and in HIV seronegative individuals. We observed increased frequencies of clusters containing hyperactivated T-bethighCD95highCD27int and proliferating T-bet+CD95highCD27+CD71+ memory B-cells in viremic HIV-1 (p < 0.001 and p < 0.001, respectively), viremic HIV-2 (p < 0.001 and p = 0.014, respectively) and in treatment-naïve aviremic HIV-2 (p = 0.004 and p = 0.020, respectively)-infected individuals, compared to seronegative individuals. In contrast, these expansions were not observed in successfully treated HIV-1-infected individuals. Finally, pseudotime trajectory inference showed that T-bet-expressing hyperactivated and proliferating memory B-cell populations were located at the terminal end of two trajectories, in both HIV-1 and HIV-2 infections. As the treatment-naïve aviremic HIV-2-infected individuals, but not the successfully ART-treated HIV-1-infected individuals, showed B-cell perturbations, our data suggest that aviremic HIV-2-infected individuals would also benefit from antiretroviral treatment.
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| 9. |
- Johansson, Jacob, et al.
(author)
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Twelve fundamental life histories evolving through allocation-dependent fecundity and survival
- 2018
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In: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 8:6, s. 3172-3186
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Journal article (peer-reviewed)abstract
- An organism's life history is closely interlinked with its allocation of energy between growth and reproduction at different life stages. Theoretical models have established that diminishing returns from reproductive investment promote strategies with simultaneous investment into growth and reproduction (indeterminate growth) over strategies with distinct phases of growth and reproduction (determinate growth). We extend this traditional, binary classification by showing that allocation-dependent fecundity and mortality rates allow for a large diversity of optimal allocation schedules. By analyzing a model of organisms that allocate energy between growth and reproduction, we find twelve types of optimal allocation schedules, differing qualitatively in how reproductive allocation increases with body mass. These twelve optimal allocation schedules include types with different combinations of continuous and discontinuous increase in reproduction allocation, in which phases of continuous increase can be decelerating or accelerating. We furthermore investigate how this variation influences growth curves and the expected maximum life span and body size. Our study thus reveals new links between eco-physiological constraints and life-history evolution and underscores how allocation-dependent fitness components may underlie biological diversity.
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| 10. |
- Lewerentz, Jacob, 1992-, et al.
(author)
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The path to immortalization of cells starts by managing stress through gene duplications
- 2023
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In: Experimental Cell Research. - : Elsevier. - 0014-4827 .- 1090-2422. ; 422:1
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Journal article (peer-reviewed)abstract
- The genomes of immortalized cell lines (and cancer cells) are characterized by multiple types of aberrations, ranging from single nucleotide polymorphisms (SNPs) to structural rearrangements that have accumulated over time. Consequently, it is difficult to estimate the relative impact of different aberrations, the order of events, and which gene functions were under selective pressure at the early stage towards cellular immortalization. Here, we have established novel cell cultures derived from Drosophila melanogaster embryos that were sampled at multiple time points over a one-year period. Using short-read DNA sequencing, we show that copy-number gain in preferentially stress-related genes were acquired in a dominant fraction of cells in 300-days old cultures. Furthermore, transposable elements were active in cells of all cultures. Only a few (<1%) SNPs could be followed over time, and these showed no trend to increase or decrease. We conclude that the early cellular responses of a novel culture comprise sequence duplication and transposable element activity. During immortalization, positive selection first occurs on genes that are related to stress response before shifting to genes that are related to growth.
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