| 1. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Coupland, Victoria H, et al.
(författare)
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Hospital volume, proportion resected and mortality from oesophageal and gastric cancer : a population-based study in England, 2004-2008
- 2013
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Ingår i: Gut. - : BMJ. - 0017-5749 .- 1468-3288. ; 62:7, s. 961-966
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE:This study assessed the associations between hospital volume, resection rate and survival of oesophageal and gastric cancer patients in England.DESIGN: 62 811 patients diagnosed with oesophageal or gastric cancer between 2004 and 2008 were identified from a national population-based cancer registration and Hospital Episode Statistics-linked dataset. Cox regression analyses were used to assess all-cause mortality according to hospital volume and resection rate, adjusting for case-mix variables (sex, age, socioeconomic deprivation, comorbidity and type of cancer). HRs and 95% CIs, according to hospital volume, were evaluated for three predefined periods following surgery: <30, 30-365, and >365 days. Analysis of mortality in relation to resection rate was performed among all patients and among the 13 189 (21%) resected patients.RESULTS:Increasing hospital volume was associated with lower mortality (p(trend)=0.0001; HR 0.87, 95% CI 0.79 to 0.95 for hospitals resecting 80+ and compared with <20 patients a year). In relative terms, the association between increasing hospital volume and lower mortality was particularly strong in the first 30 days following surgery (p(trend)<0.0001; HR 0.52, (0.39 to 0.70)), but a clinically relevant association remained beyond 1 year (p(trend)=0.0011; HR 0.82, (0.72 to 0.95)). Increasing resection rates were associated with lower mortality among all patients (p(trend)<0.0001; HR 0.86, (0.84 to 0.89) for the highest, compared with the lowest resection quintile).CONCLUSIONS:With evidence of lower short-term and longer-term mortality for patients resected in high-volume hospitals, this study supports further centralisation of oesophageal and gastric cancer surgical services in England.
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| 3. |
- Giaume, Francesca, et al.
(författare)
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Two florigens and a florigen-like protein form a triple regulatory module at the shoot apical meristem to promote reproductive transitions in rice
- 2023
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Ingår i: Nature Plants. - : Springer Nature. - 2055-0278. ; 9:4, s. 525-534
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Tidskriftsartikel (refereegranskat)abstract
- Many plant species monitor and respond to changes in day length (photoperiod) for aligning reproduction with a favourable season. Day length is measured in leaves and, when appropriate, leads to the production of floral stimuli called florigens that are transmitted to the shoot apical meristem to initiate inflorescence development. Rice possesses two florigens encoded by HEADING DATE 3a (Hd3a) and RICE FLOWERING LOCUS T 1 (RFT1). Here we show that the arrival of Hd3a and RFT1 at the shoot apical meristem activates FLOWERING LOCUS T-LIKE 1 (FT-L1), encoding a florigen-like protein that shows features partially differentiating it from typical florigens. FT-L1 potentiates the effects of Hd3a and RFT1 during the conversion of the vegetative meristem into an inflorescence meristem and organizes panicle branching by imposing increasing determinacy to distal meristems. A module comprising Hd3a, RFT1 and FT-L1 thus enables the initiation and balanced progression of panicle development towards determinacy.
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| 4. |
- Laenen, Benjamin, et al.
(författare)
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Demography and mating system shape the genome-wide impact of purifying selection in Arabis alpina
- 2018
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 115:4, s. 816-821
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Tidskriftsartikel (refereegranskat)abstract
- Plant mating systems have profound effects on levels and structuring of genetic variation and can affect the impact of natural selection. Although theory predicts that intermediate outcrossing rates may allow plants to prevent accumulation of deleterious alleles, few studies have empirically tested this prediction using genomic data. Here, we study the effect of mating system on purifying selection by conducting population-genomic analyses on whole-genome resequencing data from 38 European individuals of the arctic-alpine crucifer Arabis alpina. We find that outcrossing and mixed-mating populations maintain genetic diversity at similar levels, whereas highly self-fertilizing Scandinavian A. alpina show a strong reduction in genetic diversity, most likely as a result of a postglacial colonization bottleneck. We further find evidence for accumulation of genetic load in highly self-fertilizing populations, whereas the genome-wide impact of purifying selection does not differ greatly between mixed-mating and outcrossing populations. Our results demonstrate that intermediate levels of outcrossing may allow efficient selection against harmful alleles, whereas demographic effects can be important for relaxed purifying selection in highly selfing populations. Thus, mating system and demography shape the impact of purifying selection on genomic variation in A. alpina. These results are important for an improved understanding of the evolutionary consequences of mating system variation and the maintenance of mixed-mating strategies.
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| 5. |
- Toräng, Per, et al.
(författare)
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Evolution of the selfing syndrome : Anther orientation and herkogamy together determine reproductive assurance in a self-compatible plant
- 2017
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Ingår i: Evolution. - : Wiley-Blackwell Publishing Inc.. - 0014-3820 .- 1558-5646. ; 71:9, s. 2206-2218
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Tidskriftsartikel (refereegranskat)abstract
- Capacity for autonomous self-fertilization provides reproductive assurance, has evolved repeatedly in the plant kingdom, and typically involves several changes in flower morphology and development (the selfing syndrome). Yet, the relative importance of different traits and trait combinations for efficient selfing and reproductive success in pollinator-poor environments is poorly known. In a series of experiments, we tested the importance of anther-stigma distance and the less studied trait anther orientation for efficiency of selfing in the perennial herb Arabis alpina. Variation in flower morphology among eight self-compatible European populations was correlated with efficiency of self-pollination and with pollen limitation in a common-garden experiment. To examine whether anther-stigma distance and anther orientation are subject to directional and/or correlational selection, and whether this is because these traits affect pollination success, we planted a segregating F2 population at two native field sites. Selection strongly favored a combination of introrse anthers and reduced anther-stigma distance at a site where pollinator activity was low, and supplemental hand-pollination demonstrated that this was largely because of their effect on securing self-pollination. The results suggest that concurrent shifts in more than one trait can be crucial for the evolution of efficient self-pollination and reproductive assurance in pollinator-poor habitats.
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| 6. |
- Toräng, Per, et al.
(författare)
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Large-scale adaptive differentiation in the alpine perennial herb Arabis alpina
- 2015
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 206:1, s. 459-470
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Tidskriftsartikel (refereegranskat)abstract
- Information about the incidence and magnitude of local adaptation can help to predict the response of natural populations to a changing environment, and should be of particular interest in arctic and alpine environments where the effects of climate change are expected to be severe. To quantify adaptive differentiation in the arctic-alpine perennial herb Arabis alpina, we conducted reciprocal transplant experiments for 3yr between Spanish and Scandinavian populations. At the sites of one Spanish and one Scandinavian population, we planted seedlings representing two Spanish and four Scandinavian populations, and recorded survival, flowering propensity and fecundity. The experiment was replicated in two subsequent years. The results demonstrate strong adaptive differentiation between A.alpina populations from the two regions. At the field site in Spain, survival and fruit production of Spanish populations were higher than those of Scandinavian populations, while the opposite was true at the site in Scandinavia, and these differences were consistent across years. By comparison, fitness varied little among populations from the same region. The results suggest that the magnitude and geographical scale of local adaptation need to be considered in predictions of the effects of global change on the dynamics of arctic and alpine plant populations.
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| 7. |
- Wunder, Jörg, et al.
(författare)
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Adaptation of perennial flowering phenology across the European range of Arabis alpina
- 2023
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : Royal Society. - 0962-8452 .- 1471-2954. ; 290:2011
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Tidskriftsartikel (refereegranskat)abstract
- Flowering phenology is important in the adaptation of many plants to their local environment, but its adaptive value has not been extensively studied in herbaceous perennials. We used Arabis alpina as a model system to determine the importance of flowering phenology to fitness of a herbaceous perennial with a wide geographical range. Individual plants representative of local genetic diversity (accessions) were collected across Europe, including in Spain, the Alps and Scandinavia. The flowering behaviour of these accessions was documented in controlled conditions, in common-garden experiments at native sites and in situ in natural populations. Accessions from the Alps and Scandinavia varied in whether they required exposure to cold (vernalization) to induce flowering, and in the timing and duration of flowering. By contrast, all Spanish accessions obligately required vernalization and had a short duration of flowering. Using experimental gardens at native sites, we show that an obligate requirement for vernalization increases survival in Spain. Based on our analyses of genetic diversity and flowering behaviour across Europe, we propose that in the model herbaceous perennial A. alpina, an obligate requirement for vernalization, which is correlated with short duration of flowering, is favoured by selection in Spain where the plants experience a long growing season.
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