| 1. |
- Householder, John Ethan, et al.
(författare)
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One sixth of Amazonian tree diversity is dependent on river floodplains
- 2024
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Ingår i: NATURE ECOLOGY & EVOLUTION. - 2397-334X.
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Tidskriftsartikel (refereegranskat)abstract
- Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.
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| 2. |
- Luize, Bruno Garcia, et al.
(författare)
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Geography and ecology shape the phylogenetic composition of Amazonian tree communities
- 2024
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Ingår i: JOURNAL OF BIOGEOGRAPHY. - 0305-0270 .- 1365-2699.
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and v & aacute;rzea forest types, the phylogenetic composition varies by geographic region, but the igap & oacute; and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R-2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R-2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions.
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| 3. |
- ter Steege, Hans, et al.
(författare)
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Mapping density, diversity and species-richness of the Amazon tree flora
- 2023
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Ingår i: COMMUNICATIONS BIOLOGY. - 2399-3642. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution. A study mapping the tree species richness in Amazonian forests shows that soil type exerts a strong effect on species richness, probably caused by the areas of these forest types. Cumulative water deficit, tree density and temperature seasonality affect species richness at a regional scale.
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| 4. |
- Deb, S., et al.
(författare)
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SUPERIOR SVG: no touch saphenous harvesting to improve patency following coronary bypass grafting (a multi-Centre randomized control trial, NCT01047449)
- 2019
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Ingår i: Journal of Cardiothoracic Surgery. - : Springer Science and Business Media LLC. - 1749-8090. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundSingle centre studies support No Touch (NT) saphenous vein graft (SVG) harvesting technique. The primary objective of the SUPERIOR SVG study was to determine whether NT versus conventional (CON) SVG harvesting was associated with improved SVG patency 1year after coronary artery bypass grafting surgery (CABG).MethodsAdults undergoing isolated CABG with at least 1 SVG were eligible. CT angiography was performed 1-year post CABG. Leg adverse events were assessed with a questionnaire. A systematic review was performed for published NT graft patency studies and results aggregated including the SUPERIOR study results.ResultsTwo hundred and-fifty patients were randomized across 12-centres (NT 127 versus CON 123 patients). The primary outcome (study SVG occlusion or cardiovascular (CV) death) was not significantly different in NT versus CON (NT: 7/127 (5.5%), CON 13/123 (10.6%), p=0.15). Similarly, the proportion of study SVGs with significant stenosis or total occlusion was not significantly different between groups (NT: 8/102 (7.8%), CON: 16/107 (15.0%), p=0.11). Vein harvest site infection was more common in the NT patients 1month postoperatively (23.3% vs 9.5%, p<0.01). Including this study's results, in a meta-analysis, NT was associated with a significant reduction in SVG occlusion, Odds Ratio 0.49, 95% Confidence Interval 0.29-0.82, p=0.007 in 3 randomized and 1 observational study at 1year postoperatively.ConclusionsThe NT technique was not associated with improved patency of SVGs at 1-year following CABG while early vein harvest infection was increased. The aggregated data is supportive of an important reduction of SVG occlusion at 1year with NT harvesting.Trial registrationNCT01047449.
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| 5. |
- Bruneau, Anne, et al.
(författare)
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Advances in Legume Systematics 14. Classification of Caesalpinioideae. Part 2: Higher-level classification
- 2024
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Ingår i: PhytoKeys. - Sofia : Pensoft Publishers. - 1314-2011 .- 1314-2003. ; 240, s. 1-552
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Tidskriftsartikel (refereegranskat)abstract
- Caesalpinioideae is the second largest subfamily of legumes (Leguminosae) with ca. 4680 species and 163 genera. It is an ecologically and economically important group formed of mostly woody perennials that range from large canopy emergent trees to functionally herbaceous geoxyles, lianas and shrubs, and which has a global distribution, occurring on every continent except Antarctica. Following the recent re-circumscription of 15 Caesalpinioideae genera as presented in Advances in Legume Systematics 14, Part 1, and using as a basis a phylogenomic analysis of 997 nuclear gene sequences for 420 species and all but five of the genera currently recognised in the subfamily, we present a new higher-level classification for the subfamily. The new classification of Caesalpinioideae comprises eleven tribes, all of which are either new, reinstated or re-circumscribed at this rank: Caesalpinieae Rchb. (27 genera / ca. 223 species), Campsiandreae LPWG (2 / 5-22), Cassieae Bronn (7 / 695), Cera-tonieae Rchb. (4 / 6), Dimorphandreae Benth. (4 / 35), Erythrophleeae LPWG (2 /13), Gleditsieae Nakai (3 / 20), Mimoseae Bronn (100 / ca. 3510), Pterogyneae LPWG (1 / 1), Schizolobieae Nakai (8 / 42-43), Sclerolobieae Benth. & Hook. f. (5 / ca. 113). Although many of these lineages have been recognised and named in the past, either as tribes or informal generic groups, their circumscriptions have varied widely and changed over the past decades, such that all the tribes described here differ in generic membership from those previously recognised. Importantly, the approximately 3500 species and 100 genera of the former subfamily Mimosoideae are now placed in the reinstated, but newly circumscribed, tribe Mimoseae. Because of the large size and ecological importance of the tribe, we also provide a clade-based classification system for Mimoseae that includes 17 named lower-level clades. Fourteen of the 100 Mimoseae genera remain unplaced in these lower-level clades: eight are resolved in two grades and six are phylogenetically isolated monogeneric lineages. In addition to the new classification, we provide a key to genera, morphological descriptions and notes for all 163 genera, all tribes, and all named clades. The diversity of growth forms, foliage, flowers and fruits are illustrated for all genera, and for each genus we also provide a distribution map, based on quality-controlled herbarium specimen localities. A glossary for specialised terms used in legume morphology is provided. This new phylogenetically based classification of Caesalpinioideae provides a solid system for communication and a framework for downstream analyses of biogeography, trait evolution and diversification, as well as for taxonomic revision of still understudied genera.
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| 6. |
- Dreifaldt, Mats, et al.
(författare)
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The ‘‘no-touch’’ harvesting technique for vein grafts in coronary artery bypass surgery preserves an intact vasa vasorum
- 2011
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Ingår i: The Internet Journal of Thoracic and Cardiovascular Surgery. - New York, USA : Elsevier. - 1524-0274 .- 0022-5223. ; 141:1, s. 145-150
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Our objective was to evaluate the impact of vein graft harvesting technique on structure and function of vasa vasorum.Methods: Paired segments of great saphenous veins harvested either with conventional harvesting technique or no-touch technique were obtained from 9 consecutive patients undergoing coronary artery bypass grafting. Quantitative measurements, using immunohistochemistry and morphometry, were performed. Ultrastructural analyses of vasa vasorum were performed with electron microscopy. Video footage of superficial vasa vasorum in an implanted saphenous vein graft harvested with the no-touch technique was captured during a coronary bypass operation and is presented for online viewing.Results: The total area of vasa vasorum in vein grafts harvested with the conventional technique was significantly reduced both in the media (P¼.007) and in the adventitia (P¼.014) compared with vein grafts harvested with the no-touch technique. Ultrastructural findings indicated that the no-touch technique preserved an intact vasa vasorum whereas the conventional technique did not. Video footage showed retrograde flow in the vasa vasorum in vein graft harvested with the no-touch technique.Conclusions: These findings showthat the no-touch technique for saphenous vein graft harvesting for coronary bypass grafting preserves an intact vasa vasorum. This could represent one of the mechanisms underlying the improved patency of saphenous vein grafts harvested with this technique.
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| 7. |
- Tsui, Janice C. S., et al.
(författare)
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Localization of nitric oxide synthase in saphenous vein grafts harvested with a novel "no-touch" technique : potential role of nitric oxide contribution to improved early graft patency rates.
- 2002
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Ingår i: Journal of Vascular Surgery. - New York, USA : Elsevier. - 0741-5214 .- 1097-6809. ; 35:2, s. 356-362
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The use of the saphenous vein in coronary artery bypass graft surgery is associated with high 1-year occlusion rates of as much as 30%. A new "no-touch" technique of saphenous vein harvesting in which the vein is harvested with a pedicle of surrounding tissue and not distended may result in improved early patency rates. We hypothesize that nitric oxide synthase is better preserved with the no-touch technique, and the aim of this study was the investigation of whether nitric oxide synthase distribution and quantity in saphenous veins harvested with the no-touch technique differ from those veins harvested with the conventional technique. The separate contribution of perivascular tissue removal and distension to alterations in nitric oxide synthase was also studied.Methods: Segments of 10 saphenous veins were harvested from 10 patients who underwent coronary artery bypass grafting surgery with the no-touch and conventional techniques. Samples were also taken from segments that were stripped of surrounding tissue but not distended. Nitric oxide synthase distribution was studied with reduced nicotinamide adenine dinucleotide phosphate--diaphorase histochemistry, and staining was quantified with image analysis. Immunohistochemistry was used for the identification of specific nitric oxide synthase isoforms, and immunomarkers were used for the identification of associated cell types.Results: Nitric oxide synthase content was higher in no-touch vessels as compared with conventionally harvested vessels (35.5%; P <.05, with analysis of variance). This content was associated with endothelial nitric oxide synthase on the lumen while all three isoforms were present in the media. In the intact adventitia of no-touch vessels, all three isoforms of nitric oxide synthase were also present, associated with microvessels and perivascular nerves. Perivascular tissue stripping and venous distension both contribute to the reduced nitric oxide synthase in conventionally harvested veins.Conclusion: The new no-touch technique of saphenous vein harvesting preserves nitric oxide synthase, which suggests that improved nitric oxide availability may be an important mechanism in the success of this technique.
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| 8. |
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| 9. |
- Dreifaldt, Mats, et al.
(författare)
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The Vasa Vasorum and Associated Endothelial Nitric Oxide Synthase is More Important for Saphenous Vein Than Arterial Bypass Grafts
- 2013
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Ingår i: Angiology. - : SAGE Publications. - 0003-3197 .- 1940-1574. ; 64:4, s. 293-299
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Tidskriftsartikel (refereegranskat)abstract
- No-touch (NT) saphenous vein (SV) grafts are superior to SVs harvested by the conventional technique (CT), with a patency comparable with the internal thoracic artery (ITA). Preservation of the vasa vasorum is implicated in the success of NT harvesting. We compared the vasa vasorum and endothelial nitric oxide synthase (eNOS) in NT SV with ITA and radial artery (RA) grafts. Skeletonized SV (SSV) was also analyzed. The NT SV had a higher number and larger vasa vasorum compared with ITA (P = .0001) and RA (P = .0004) that correlated with eNOS protein. Activity of eNOS in SSV grafts was significantly lower than NT SV grafts (P = 004). Since a high proportion of the vasa vasorum are removed in SSV using the CT, we suggest that preservation of the vasa vasorum and eNOS-derived NO contributes to the high patency for NT as compared with SSV grafts.
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| 10. |
- Souza, Domingos S. R., et al.
(författare)
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Harvesting the saphenous vein with surrounding tissue for CABG provides long-term graft patency comparable to the left internal thoracic artery : results of a randomized longitudinal trial
- 2006
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Ingår i: Journal of Thoracic and Cardiovascular Surgery. - : Elsevier BV. - 0022-5223 .- 1097-685X. ; 132:2, s. 373-U75
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Conventional harvesting of the saphenous vein in coronary artery bypass surgery produces vessel damage that contributes to graft failure. A novel "no touch" technique provides high short- and long-term patency rates.Method: This randomized longitudinal trial compares graft patency of two patient groups undergoing coronary artery bypass surgery. Conventional: 52 patients had their veins stripped, distended, and stored in saline solution. No-touch: 52 patients had veins removed with surrounding tissue, not distended, and stored in heparinized blood. Angiographic assessment was performed at mean time 18 months after the operation in 46 patients in the conventional group and 45 patients in the no-touch group and repeated at mean time 8.5 years in 37 patients from both groups.Results: The distribution of the grafts to the recipient coronary arteries regarding their size and quality was similar in both groups. The angiographic assessment at 18 months postoperatively showed 89% conventional versus 95% no-touch grafts were patent. Repeated angiography at 8.5 years showed a patency rate for the conventional group of 76% and 90% for the no- touch group ( P =.01). The multivariate analysis showed that the most important surgical factors for graft patency were the technique of harvesting ( odds ratio = 3.7, P =.007) for the no- touch versus the conventional technique and the vein quality before implantation ( odds ratio = 3.2, P =.007) for veins that were of good quality. By comparison the patency of the thoracic artery grafts was 90%.Conclusion: Harvesting the saphenous vein with surrounding tissue provides high short- and long-term patency rates comparable to the left internal thoracic artery.
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