| 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. |
- Atem de Carvalho, Rogerio, et al.
(författare)
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Key aspects of free and open source enterprise resource planning systems
- 2012
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Ingår i: Free and Open Source Enterprise Resource Planning: Systems and Strategies. - : IGI Global. - 9781613504864 - 1613504861 - 9781613504871 ; , s. 1-17
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Bokkapitel (refereegranskat)abstract
- This chapter introduces basic differences between Free/Open Source Enterprise Resources Planning systems (FOS-ERP) and Proprietary ERP (P-ERP), revisiting the previous work of Carvalho (2008). Taking into account that some years has passed and the economic downturn came, it updates key aspects of FOS-ERP under both vendor and adopter perspectives. Like its predecessor, this chapter contributes to broaden the discussion around FOS-ERP, showing that its differences from its proprietary counterpart go beyond the cost factor.
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| 5. |
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| 6. |
- Adolfsson, J., et al.
(författare)
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SAMPA Chip : The New 32 Channels ASIC for the ALICE TPC and MCH Upgrades
- 2017
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 12:4
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the test results of the second prototype of SAMPA, the ASIC designed for the upgrade of read-out front end electronics of the ALICE Time Projection Chamber (TPC) and Muon Chamber (MCH). SAMPA is made in a 130 nm CMOS technology with 1.25 V nominal voltage supply and provides 32 channels, with selectable input polarity, and three possible combinations of shaping time and sensitivity. Each channel consists of a Charge Sensitive Amplifier, a semi-Gaussian shaper and a 10-bit ADC; a Digital Signal Processor provides digital filtering and compression capability. In the second prototype run both full chip and single test blocks were fabricated, allowing block characterization and full system behaviour studies. Experimental results are here presented showing agreement with requirements for both the blocks and the full chip.
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| 7. |
- Atem de Carvalho, Rogerio, et al.
(författare)
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Towards more flexible enterprise information systems
- 2012
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Ingår i: Enterprise Information Systems of the Future : Lecture Notes in Business Information Processing, vol 139 - Lecture Notes in Business Information Processing, vol 139. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 1865-1356 .- 1865-1348. - 9783642366109 - 9783642366116 ; , s. 157-164
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Konferensbidrag (refereegranskat)abstract
- The aim of this paper is to present the software development techniques used to build the EIS Patterns development framework, which is a testbed for a series of techniques that aim at giving more flexibility to EIS in general. Some of these techniques are customizations or extensions of practices created by the agile software development movement, while others represent new proposals. This paper also aims at helping promoting more discussion around the EIS development questions, since most of research papers in EIS area focus on deployment, IT, or business related issues, leaving the discussion on development techniques ill-treated.
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| 8. |
- Carvalho, Rogerio Atem de, et al.
(författare)
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Agile Software Development for Customizing ERPs
- 2010
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Ingår i: Enterprise Information Systems and Implementing IT Infrastructures: Challenges and Issues. - 9781615206254 ; , s. 20-39
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 9. |
- Carvalho, Rogerio Atem de, et al.
(författare)
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Towards more flexible enterprise information systems
- 2013
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Ingår i: Enterprise Information Systems of the Future: 6th IFIP WG 8.9 Working Conference, CONFENIS 2012, Ghent, Belgium, September 19-21, 2012, Revised Selected Papers. - 9783642366109 ; 139, s. 157-164
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Bokkapitel (refereegranskat)
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| 10. |
- Carvalho, Rogerio de Atem, et al.
(författare)
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ERP Licensing Perspectives on Adoption of ERPs in Small and Medium-sized Enterprises
- 2010
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Ingår i: [Host publication title missing]. - 2177-8140.
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Konferensbidrag (refereegranskat)abstract
- The ERP market has been changing since the implementation peaks observed around Y2K, when most of the high-end adopters take their chance of substituting legacy systems while implementing integrated management. This adoption movement from bigger companies created a reaction on the Small and Medium-sized Enterprises (SMEs) ERP market: on the vendor side, it was necessary to find new market segments to keep profiting, given the saturated high-end market; on the adopter side, integrated management is necessary for both integration to large supply chains, and to stay competitive on a globalized market. However, ERP adoption by SMEs faces the problem of the high costs associated to implementation and customization. Given that problem and the improvements on various free/open source projects, this type of licensing have started to become more attractive on the enterprise computing arena. This paper aims to explore the merger of SMEs and ERP under the licensing terms perspectives, by comparing free/open source ERP and proprietary ERP.
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