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| 2. |
- Bengtson, Annika, et al.
(författare)
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Phylogeny and evolution of the South African genus Metalasia (Asteraceae-Gnaphalieae) inferred from molecular and morphological data
- 2014
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Ingår i: Botanical journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4074 .- 1095-8339. ; 174:2, s. 173-198
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Tidskriftsartikel (refereegranskat)abstract
- Metalasia is a genus in tribe Gnaphalieae (Asteraceae), endemic to South Africa and with its main distribution in the Cape Floristic Region. The genus comprises 57 species and, with a number of closely related genera, it constitutes the Metalasia clade'. A species-level phylogenetic analysis is presented, based on DNA sequences from two nuclear (internal and external transcribed spacer: ITS, ETS) and two plastid (psbA-trnH, trnL-trnF) regions together with morphological data. Analyses combining molecular and morphological data attempt not only to resolve species interrelationships, but also to detect patterns in character evolution. Phylogenetic analyses corroborate our earlier study and demonstrate that Metalasia is formed of two equally sized, well-supported sister groups, one of which is characterized by papillose cypselas. The results differ greatly from earlier hypotheses based on morphology alone, as few morphological characters support the phylogenetic patterns obtained. The two clades of Metalasia do, however, appear to differ in distribution, corresponding to the different rainfall regimes of South Africa. Analyses show a few taxa to be problematic; one example is the widely distributed M.densa which appears to be an intricate species complex.
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| 3. |
- Bengtson, Annika, et al.
(författare)
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PHYLOGENY AND GENERIC DELIMITATION OF THE METALASIA CLADE (ASTERACEAE-GNAPHALIEAE)
- 2011
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Ingår i: International journal of plant sciences. - : University of Chicago Press. - 1058-5893 .- 1537-5315. ; 172:8, s. 1067-1075
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Tidskriftsartikel (refereegranskat)abstract
- The Metalasia clade, which consists of the genus Metalasia and a number of much smaller satellite genera, is a South African group in the tribe Gnaphalieae (Asteraceae). This study scrutinizes the phylogenetic relationships of the Metalasia clade by means of chloroplast (trnL-trnF, psbA-trnH) and nuclear (external transcribed spacer, internal transcribed spacer) sequence data. The Metalasia clade is confirmed to be a monophyletic group, and the phylogenetic positions of the included genera are determined. The genus Metalasia may be monophyletic if the monotypic Planea is included, but the node has very poor support and further studies are needed. The Metalasia species fall into two well-supported groups, distinguishing the members of Karis's Metalasia densa group from the others. Lachnospermum is shown to be monophyletic and is placed as a possible sister group to Metalasia. Phaenocoma is placed as sister to the branch consisting of Metalasia and Lachnospermum. Calotesta, Hydroidea, and Atrichantha form a clade, with the monotypic Dolichothrix as their sister group.
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| 4. |
- Bengtson, Annika, 1982-
(författare)
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Systematics and biogeography of the South African Metalasia clade (Asteraceae-Gnaphalieae)
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The Metalasia clade (Asteraceae–Gnaphalieae) consisting of the genera Metalasia, Atrichantha, Calotesta, Dolichothrix, Hydroidea, Lachnospermum, Phaenocoma, and Planea is endemic to South Africa with a main distribution within the Cape Floristic Region (CFR), a region known for its remarkable botanical diversity.The monophyly of the Metalasia clade, the relationships of its genera, and the circumscription of these as well as their position within the tribe Gnaphalieae is investigated using molecular data. The study confirms the Metalasia clade to be a monophyletic group, untangling the relationships between the included genera.Five new Metalasia species have been described since the latest revision of the genus, three of which are described in the present work. An updated key to all 57 species of the genus is also provided.A phylogenetic study of the genus Metalasia, including all 57 species, based on a combination of morphological and molecular data shows that Metalasia consists of two sister clades, Clade A and Clade B, morphologically separated by the papillose cypselas of Clade A. Metalasia is, however, not supported as monophyletic, and Lachnospermum is placed together with the Metalasia species of Clade B. Further, the monotypic Planea, originally described as Metalasia schlechteri, is placed well within Clade B.A biogeographical study reveals Metalasia to have evolved in the CFR around 6.9 Ma. Ancestral area estimations present a possible scenario for the radiation of Metalasia and show a difference between Clade A and B, correlated to the different rainfall regimes of southern Africa. The results show that Clade B began to diversify around 6.4 Ma in the winter rainfall area, whereas the diversification of the Clade A crown group, which is estimated to only 3.3 Ma, was initiated in the all-year rainfall area.
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| 5. |
- Bengtson, Annika, et al.
(författare)
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Three new species of metalasia (asteraceae gnaphalieae) from the western cape and an updated key to the genus
- 2013
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Ingår i: South African Journal of Botany. - : Elsevier BV. - 0254-6299 .- 1727-9321. ; 84, s. 72-82
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Tidskriftsartikel (refereegranskat)abstract
- Three new species of Metalasia from the Western Cape of South Africa are described; Metalasia tristis A.Bengtson & P.O.Karis, a small shrublet from the Groot Winterhoek Mountains, and Metalasia formosa A.Bengtson & P.O.Karis and Metalasia eburnea A.Bengtson & P.O.Karis both found in the Langeberg Mountains. The morphology and relationships of the three new species are discussed, and an updated key to the genus is provided.
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| 6. |
- Bengtson, Per, et al.
(författare)
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Archaeal abundance across a pH gradient in an arable soil and its relationship with bacterial and fungal growth rates.
- 2012
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Ingår i: Applied and Environmental Microbiology. - 0099-2240. ; 78:16, s. 5906-5911
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Tidskriftsartikel (refereegranskat)abstract
- Soil pH is one of the most influential factors for the composition of bacterial and fungal communities, but the influence of soil pH on the distribution and composition of soil archaeal communities has yet to be systematically addressed. The primary aim of this study was to determine how total archaeal abundance (qPCR based estimates of 16S rRNA gene copy numbers) is related to soil pH across a pH gradient (pH 4.0-8.3). Secondarily, we wanted to assess how archaeal abundance related to bacterial and fungal growth rates across the same pH gradient. We identified two distinct and opposite effects of pH on the archaeal abundance. In the lowest pH range (pH 4.0-4.7) the abundance of archaea did not seem to respond to pH. Above this pH range there was a sharp, almost 4-fold, decrease in archaeal abundance, reaching a minimum at pH 5.1-5.2. The low archaeal abundance of archaeal 16S rRNA gene copies at this pH then sharply increased almost 150-fold with pH, resulting in an increase in the ratio between archaeal and bacterial copy numbers from a minimum of 0.002 to more than 0.07 at pH 8. The non-uniform archaeal response to pH could reflect variation in the archaeal community composition along the gradient, with some archaea adapted to acidic conditions, and others to neutral to slightly alkaline conditions. This suggestion is reinforced by observations of contrasting outcomes of the (competitive) interactions between archaea, bacteria and fungi towards the lower and higher ends of the examined pH gradient.
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| 7. |
- Bengtson, Per, et al.
(författare)
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Evidence of a strong coupling between root exudation, C and N availability, and stimulated SOM decomposition caused by rhizosphere priming effects
- 2012
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 2:8, s. 1843-1852
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Tidskriftsartikel (refereegranskat)abstract
- Increased temperatures and concomitant changes in vegetation patterns are expected to dramatically alter the functioning of northern ecosystems over the next few decades. Predicting the ecosystem response to such a shift in climate and vegetation is complicated by the lack of knowledge about the links between aboveground biota and belowground process rates. Current models suggest that increasing temperatures and rising concentrations of atmospheric CO2 will be partly mitigated by elevated C sequestration in plant biomass and soil. However, empirical evidence does not always support this assumption, as elevated temperature and CO2 concentrations also accelerate the belowground C flux, in many cases extending to increased decomposition of soil organic matter (SOM) and ultimately resulting in decreased soil C stocks. The mechanism behind the increase has remained largely unknown, but it has been suggested that priming might be the causative agent. Here, we provide quantitative evidence of a strong coupling between root exudation, SOM decomposition, and release of plant available N caused by rhizosphere priming effects. As plants tend to increase belowground C allocation with increased temperatures and CO2 concentrations, priming effects need to be considered in our long-term analysis of soil C budgets in a changing environment. The extent of priming seems to be intimately linked to resource availability, as shifts in the stoichiometric nutrient demands of plants and microorganisms will lead to either cooperation (resulting in priming) or competition (no priming will occur). The findings lead us on the way to resolve the varying response of primary production, SOM decomposition, and release of plant available N to elevated temperatures, CO2 concentrations, and N availability.
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| 8. |
- Bengtson, Per, et al.
(författare)
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Possible roles of reactive chlorine II: assessing biotic chlorination as a way for organisms to handle oxygen stress
- 2013
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Ingår i: Environmental Microbiology. - : Wiley-Blackwell. - 1462-2912 .- 1462-2920. ; 15:4, s. 991-1000
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Forskningsöversikt (refereegranskat)abstract
- Natural formation of organically bound chlorine is extensive in many environments. The enzymes associated with the formation of chlorinated organic matter are produced by a large variety of organisms. Little is known about the ecological role of the process, the key question being: why do microorganisms promote chlorination of organic matter? In a recent paper we discuss whether organic matter chlorination may be a result of antagonistic interactions among microorganisms. In the present paper we evaluate whether extracellular microbial formation of reactive chlorine may be used as a defence against oxygen stress, and we discuss whether this process is likely to contribute to the formation of chlorinated organic matter. Our analysis suggests that periodic exposure to elevated concentrations of reactive oxygen species is a common denominator among the multitude of organisms that are able to enzymatically catalyse formation of reactive chlorine. There is also some evidence suggesting that the production of such enzymes in algae and bacteria is induced by oxygen stress. The relative contribution from this process to the extensive formation of chlorinated organic matter in natural environments remains to be empirically assessed.
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| 9. |
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| 10. |
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| 11. |
- Campbell, Jocelyn, et al.
(författare)
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Does exogenous carbon extend the realized niche of canopy lichens? Evidence from sub-boreal forests in British Columbia
- 2013
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Ingår i: Ecology. - : Wiley. - 0012-9658. ; 94:5, s. 1186-1195
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Tidskriftsartikel (refereegranskat)abstract
- Foliose lichens with cyanobacterial bionts (bipartite and tripartite) form a distinct assemblage of epiphytes strongly associated with humid microclimatic conditions in inland British Columbia. Previous research showed that these cyano- and cephalolichen communities are disproportionately abundant and species-rich on conifer saplings beneath Populus compared to beneath other tree species. More revealing, lichens with cyanobacterial bionts were observed beneath Populus even in stands that did not otherwise support them. We experimentally test the hypothesis that this association is due to the interception of glucose-rich nectar that is exuded from Populus extra-floral nectaries (EFN). Using CO2 flux measurements and phospholipid fatty acid (PLFA) analysis with experimental applications of C-13(6)-labeled glucose, we demonstrate that cyano-and cephalolichens have a strong respiratory response to glucose. Lichens treated with glucose had lower net photosynthesis and higher establishment rates than control thalli. Furthermore, lichens with cyanobacterial bionts rapidly incorporate exogenous C-13 into lichen fatty acid tissues. A large proportion of the C-13 taken up by the lichens was incorporated into fungal biomarkers, suggesting that the mycobiont absorbed and assimilated the majority of applied C-13(6) glucose. Our observations suggest that both cyanolichens and cephalolichens may utilize an exogenous source of glucose, made available by poplar EFNs. The exogenous C may enable these lichens to become established by providing a source of C for fungal respiration despite drought-induced inactivity of the cyanobacterial partner. As such, the mycobiont may adopt an alternative nutritional strategy, using available exogenous carbon to extend its realized niche.
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| 12. |
- Carlsson, Michael, et al.
(författare)
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Galectin-3 guides intracellular trafficking of some human serotransferrin glycoforms
- 2013
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 288:39, s. 28398-28408
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Tidskriftsartikel (refereegranskat)abstract
- Transferrin internalization via clathrin-mediated endocytosis and subsequent recycling after iron delivery has been extensively studied. Here we demonstrate a previously unrecognized parameter regulating this recycling -the binding of galectin-3 to particular glycoforms of transferrin. Two fractions of transferrin, separated by affinity chromatography based on their binding or not to galectin-3, are targeted to kinetically different endocytic pathways in HFL-1 cells expressing galectin-3 but not in SKBR3 cells lacking galectin-3; the SKBR3 cells, however can acquire the ability to target these transferrin glycoforms differently after preloading with exogenously added galectin-3. In all, this study provides the first evidence of a functional role for transferrin glycans, in intracellular trafficking after uptake. Moreover, the galectin-3 bound glycoform increased in cancer, suggesting a pathophysiological regulation. These are novel aspects of transferrin cell biology, which has previously considered only degree of iron loading, but not other forms of heterogeneity.
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| 13. |
- Churchland, Carolyn, et al.
(författare)
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Spatial variability of soil fungal and bacterial abundance: Consequences for carbon turnover along a transition from a forested to clear-cut site
- 2013
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Ingår i: Soil Biology & Biochemistry. - : Elsevier BV. - 0038-0717. ; 63, s. 5-13
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Tidskriftsartikel (refereegranskat)abstract
- Predicted alterations in belowground plant-allocated C as a result of environmental change may cause compositional shifts in soil microbial communities, and it has been hypothesized that such alterations will influence C mitigation in forest ecosystems. In order to investigate to what degree living trees influence the abundance and activity of mycorrhizal fungi, saprotrophic fungi, and bacteria we used a geostatistical approach to examine natural abundance stable-isotope-ratios of soil microbial PLFAs, respired CO2, and different soil organic C pools in a 100 point grid extending from an area of retention trees into a clear-cut area. Labile C from trees was the major source of C for the fungal communities and influenced the composition of the microbial community and soil respiration rates up to ten meters into the clear-cut. When the input of labile plant C decreased, it appeared that microorganisms became increasingly dependent on recycled C released during microbial turnover, resulting in a decrease in soil respiration. Our findings demonstrate that plants not only influence the structure and function of soil microbial communities but also act as important regulators of belowground C flux, soil C sequestration and, ultimately, soil C stocks. (c) 2013 Elsevier Ltd. All rights reserved.
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| 14. |
- Drevenhorn, Eva, et al.
(författare)
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Consultation training of nurses for cardiovascular prevention - A randomized study of 2 years duration
- 2012
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Ingår i: Blood Pressure. - : Informa Healthcare. - 0803-7051 .- 1651-1999. ; 21:5, s. 293-299
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to increase patients adherence to the treatment of hypertension through the consultation training of nurses. Thirty-three nurses were included in the study. In the intervention group (IG), 19 nurses took part in a 3-day residential training course on the Stages of Change model, Motivational Interviewing and guidelines for cardiovascular prevention, and recruited 153 patients. Sixteen nurses in the control group (CG) recruited 59 patients. A decrease in systolic and diastolic blood pressure and total cholesterol was noticed in both groups over the 2 years. Heart rate (p = 0.027), body mass index (p = 0.019), weight (p = 0.0001), waist (p = 0.041), low-density lipoprotein-cholesterol (p = 0.0001), the waist-hip ratio (p = 0.024), and perceived stress (p = 0.001) decreased to any great extent only in the IG. After 2 years, 52.6% of the patients in the IG (p = 0.13) reached the target of andlt;= 140/90 mmHg in blood pressure compared with 39.2% in the CG. For self-reported physical activity, there was a significant (p = 0.021) difference between the groups. The beneficial effects of the consultation training on patients weight parameters, physical activity, perceived stress and the proportion of patients who achieved blood pressure control emphasize consultation training and the use of behavioural models in motivating patients to adhere to treatment.
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| 15. |
- Drevenhorn, Eva, et al.
(författare)
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Effects on hypertensive patients' satisfaction with information about their medication after nurses' consultation training
- 2014
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Ingår i: Pragmatic and Observational Research. - : Dove Press. - 1179-7266. ; 5, s. 35-41
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is a well-known problem in hypertension care with patients' adherence to treatment. Patients who score high in answering the instrument Satisfaction with Information about Medicine Scale are reported to have greater adherence to their medication.Aim: To explore how hypertensive patients' satisfaction with information about their medicines was affected by nurses' education in Motivational Interviewing.Material and methods: The Stages of Change model and Motivational Interviewing was the theoretical base for consultation training for nurses. Nineteen nurses attended 3 days of video-recorded consultation training with simulated patients. They were updated in hypertensive medication and were trained in motivating patients to improve their self-management as well as adherence to lifestyle changes and medication. The satisfaction with information instrument identifies patients' satisfaction with information about the action and usage of medication as well as potential problems with it. The instrument was used to assess how well the needs of individual patients for medicine information were met at baseline and 2 years after the training. The 19 trained nurses in the intervention group worked with 137 patients, and a control group of 16 nurses, who gave normal care, worked with 51 patients.Results: There was a difference between the intervention and control group in total score (P=0.028) 2 years after the intervention. Patients in the intervention group perceived higher satisfaction with the action and usage of their medication (P=0.001) and a lower degree of potential problems with their medication (P=0.001). Patients in the control group also perceived a lower degree of potential problems with their medication (P=0.028).Conclusion: We suggest that consultation training for nurses with the aim of motivating patients to be more self-directed in their self-care improves satisfaction with information about medication.
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| 16. |
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| 17. |
- Sterngren, Anna, et al.
(författare)
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Archaeal abundance in relation to root and fungal exudation rates
- 2012
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Ingår i: FEMS Microbiology Ecology. - : Oxford University Press (OUP). - 1574-6941 .- 0168-6496. ; 80:2, s. 305-311
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Tidskriftsartikel (refereegranskat)abstract
- Archaea are ubiquitous in forest soils, but little is known about the factors regulating their abundance and distribution. Low molecular weight organic compounds represent an important energy source for archaea in marine environments, and it is reasonable to suspect that archaeal abundance is dependent on such compounds in soils as well, represented by, for example, plant and fungal exudates. To test this hypothesis, we designed a microcosm experiment in which we grew ponderosa pine, sitka spruce, and western hemlock in forest soil. Root and mycorrhizal exudation rates were estimated in a 13C pulse-chase experiment, and the number of archaeal and bacterial 16S rRNA genes was determined by qPCR. Archaeal abundance differed among plant species, and the number of archaeal 16S rRNA genes was generally lower in soil receiving high concentration of exudates. The mycorrhizal fungi of ponderosa pine seemed to favor archaea, while no such effect was found for mycorrhized sitka spruce or western hemlock. The low abundance of archaea in the proximity of roots and mycorrhiza may be a result of slow growth rates and poor competitive ability of archaea vs. bacteria and does not necessarily reflect a lack of heterotrophic abilities of the archaeal community.
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| 18. |
- Thang, ND, et al.
(författare)
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Characteristics of and outcome for patients with chest pain in relation to transport by the emergency medical services in a 20-year perspective
- 2012
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Ingår i: American Journal of Emergency Medicine. - : Elsevier BV. - 0735-6757 .- 1532-8171. ; 30:9, s. 1788-1795
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Tidskriftsartikel (refereegranskat)abstract
- AIM: The aims of this study were to describe the characteristics of and outcome of patients with chest pain in relation to transport by the emergency medical services (EMS) and to describe possible changes in this relationship in a 20-year perspective. METHODS: In the 2 periods, 1986 to 1987 and 2008, all patients with chest pain admitted to hospitals in Gothenburg, Sweden, were retrospectively evaluated in terms of previous history, final diagnosis, and mortality. P values were age adjusted. RESULTS: In 1986 to 1987 and 2008, 34% of 4270 patients with chest pain and 39% of 2286 patients, respectively, were transported to the hospital by the EMS (P = .0001). In both periods, patients who used EMS were older and had a higher prevalence of previous cardiovascular diseases and more often had a final diagnosis of acute myocardial infarction (AMI) than those who did not use EMS. The EMS users were more frequently hospitalized in 1986 to 1987 than in 2008 (P < .0001). Emergency medical service use was related to a significantly higher age-adjusted 1-year mortality in both periods for all patients with chest pain as well as for those hospitalized. Among hospitalized patients with myocardial ischemia and among patients with a final diagnosis of AMI, EMS use was associated with a higher 30-day mortality in 1986 to 1987. Regardless of the use of EMS, there was a decrease in the proportion of patients developing AMI as well as the rate of death at 30 days and 1 year in 2008 as compared with 1986 to 1987. CONCLUSIONS: For 20 years, the proportion of patients with chest pain using the EMS increased. EMS users were more frequently hospitalized in 1986 to 1987 than in 2008. In overall terms, mortality was higher among EMS users than among nonusers in both periods. Among hospitalized patients with myocardial ischemia and among patients with a final diagnosis of AMI, EMS use was associated with a higher 30-day mortality only in 1986 to 1987.
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| 19. |
- Thang, Nguyen Dang, et al.
(författare)
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Patients admitted to hospital with chest pain - Changes in a 20-year perspective.
- 2013
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Ingår i: International journal of cardiology. - : Elsevier BV. - 1874-1754 .- 0167-5273. ; 166:1, s. 141-146
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To describe the differences in characteristics and outcome between two consecutive series of patients admitted to hospital with chest pain in a 20-year perspective. Particular emphasis is placed on changes in outcome in relation to the initial electrocardiogram (ECG). SUBJECTS: In the two periods, 1986-1987 and 2008, all patients with chest pain admitted to the study hospitals in Gothenburg, Sweden, were included. RESULTS: Five thousand and sixteen patients were registered in a period of 21months in 1986-1987 and 2287 patients were registered during 3months in 2008. In a comparison of the two time periods, the age of chest pain patients was not significantly different (mean age 60.1±17.8years in 1986-1987 and 59.8±19.1years in 2008, p=0.50). There was a lower prevalence of previous angina pectoris, congestive heart failure and current smoking in the second period, whereas a history of acute myocardial infarction, hypertension and diabetes mellitus had become more prevalent. The use of cardio-protective drugs increased and ECG changes indicating acute myocardial ischemia on admission to hospital decreased. Length of hospitalisation was reduced from a median of 5days to 3days (p<0.0001). A significant decrease in 30-day and 1-year mortality was found (3.8% in 1986-1987 vs 2.0% in 2008 and 9.9% vs 6.3% respectively, p<0.0001 for both comparisons). CONCLUSIONS: During a period of 20years, the characteristics and outcome of patients admitted to hospital with chest pain changed. The most important changes were a lower prevalence of ECG signs indicating acute myocardial ischemia on admission, shorter hospitalisation time and a lower 30-day and 1-year mortality.
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