| 1. |
- Zamora, Juan Carlos, et al.
(författare)
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Considerations and consequences of allowing DNA sequence data as types of fungal taxa
- 2018
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Ingår i: IMA Fungus. - : INT MYCOLOGICAL ASSOC. - 2210-6340 .- 2210-6359. ; 9:1, s. 167-185
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Tidskriftsartikel (refereegranskat)abstract
- Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.
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| 2. |
- Letcher, Susan G., et al.
(författare)
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Environmental gradients and the evolution of successional habitat specialization : a test case with 14 Neotropical forest sites
- 2015
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Ingår i: Journal of Ecology. - : Wiley. - 0022-0477 .- 1365-2745. ; 103:5
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Tidskriftsartikel (refereegranskat)abstract
- * Successional gradients are ubiquitous in nature, yet few studies have systematically examined the evolutionary origins of taxa that specialize at different successional stages. Here we quantify successional habitat specialization in Neotropical forest trees and evaluate its evolutionary lability along a precipitation gradient. Theoretically, successional habitat specialization should be more evolutionarily conserved in wet forests than in dry forests due to more extreme microenvironmental differentiation between early and late-successional stages in wet forest. * We applied a robust multinomial classification model to samples of primary and secondary forest trees from 14 Neotropical lowland forest sites spanning a precipitation gradient from 788 to 4000 mm annual rainfall, identifying species that are old-growth specialists and secondary forest specialists in each site. We constructed phylogenies for the classified taxa at each site and for the entire set of classified taxa and tested whether successional habitat specialization is phylogenetically conserved. We further investigated differences in the functional traits of species specializing in secondary vs. old-growth forest along the precipitation gradient, expecting different trait associations with secondary forest specialists in wet vs. dry forests since water availability is more limiting in dry forests and light availability more limiting in wet forests. * Successional habitat specialization is non-randomly distributed in the angiosperm phylogeny, with a tendency towards phylogenetic conservatism overall and a trend towards stronger conservatism in wet forests than in dry forests. However, the specialists come from all the major branches of the angiosperm phylogeny, and very few functional traits showed any consistent relationships with successional habitat specialization in either wet or dry forests. * Synthesis. The niche conservatism evident in the habitat specialization of Neotropical trees suggests a role for radiation into different successional habitats in the evolution of species-rich genera, though the diversity of functional traits that lead to success in different successional habitats complicates analyses at the community scale. Examining the distribution of particular lineages with respect to successional gradients may provide more insight into the role of successional habitat specialization in the evolution of species-rich taxa.
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| 3. |
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The Seventeenth Data Release of the Sloan Digital Sky Surveys : Complete Release of MaNGA, MaStar, and APOGEE-2 Data
- 2022
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Ingår i: Astrophysical Journal Supplement Series. - : Institute of Physics (IOP). - 0067-0049 .- 1538-4365. ; 259:2
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Tidskriftsartikel (refereegranskat)abstract
- This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 survey that publicly releases infrared spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the subsurvey Time Domain Spectroscopic Survey data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey subsurvey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated value-added catalogs. This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper, Local Volume Mapper, and Black Hole Mapper surveys.
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| 4. |
- Arndt, D. S., et al.
(författare)
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STATE OF THE CLIMATE IN 2017
- 2018
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Ingår i: Bulletin of The American Meteorological Society - (BAMS). - : American Meteorological Society. - 0003-0007 .- 1520-0477. ; 99:8, s. S1-S310
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Forskningsöversikt (refereegranskat)
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| 5. |
- Blunden, Jessica, et al.
(författare)
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State of the Climate in 2012
- 2013
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Ingår i: Bulletin of The American Meteorological Society - (BAMS). - 0003-0007 .- 1520-0477. ; 94:8, s. S1-S258
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Tidskriftsartikel (refereegranskat)abstract
- For the first time in serveral years, the El Nino-Southern Oscillation did not dominate regional climate conditions around the globe. A weak La Ni a dissipated to ENSOneutral conditions by spring, and while El Nino appeared to be emerging during summer, this phase never fully developed as sea surface temperatures in the eastern conditions. Nevertheless, other large-scale climate patterns and extreme weather events impacted various regions during the year. A negative phase of the Arctic Oscillation from mid-January to early February contributed to frigid conditions in parts of northern Africa, eastern Europe, and western Asia. A lack of rain during the 2012 wet season led to the worst drought in at least the past three decades for northeastern Brazil. Central North America also experienced one of its most severe droughts on record. The Caribbean observed a very wet dry season and it was the Sahel's wettest rainy season in 50 years. Overall, the 2012 average temperature across global land and ocean surfaces ranked among the 10 warmest years on record. The global land surface temperature alone was also among the 10 warmest on record. In the upper atmosphere, the average stratospheric temperature was record or near-record cold, depending on the dataset. After a 30-year warming trend from 1970 to 1999 for global sea surface temperatures, the period 2000-12 had little further trend. This may be linked to the prevalence of La Ni a-like conditions during the 21st century. Heat content in the upper 700 m of the ocean remained near record high levels in 2012. Net increases from 2011 to 2012 were observed at 700-m to 2000-m depth and even in the abyssal ocean below. Following sharp decreases in to the effects of La Ni a, sea levels rebounded to reach records highs in 2012. The increased hydrological cycle seen in recent years continued, with more evaporation in drier locations and more precipitation in rainy areas. In a pattern that has held since 2004, salty areas of the ocean surfaces and subsurfaces were anomalously salty on average, while fresher areas were anomalously fresh. Global tropical cyclone activity during 2012 was near average, with a total of 84 storms compared with the 1981-2010 average of 89. Similar to 2010 and 2011, the North Atlantic was the only hurricane basin that experienced above-normal activity. In this basin, Sandy brought devastation to Cuba and parts of the eastern North American seaboard. All other basins experienced either near-or below-normal tropical cyclone activity. Only three tropical cyclones reached Category 5 intensity-all in Bopha became the only storm in the historical record to produce winds greater than 130 kt south of 7 N. It was also the costliest storm to affect the Philippines and killed more than 1000 residents. Minimum Arctic sea ice extent in September and Northern Hemisphere snow cover extent in June both reached new record lows. June snow cover extent is now declining at a faster rate (-17.6% per decade) than September sea ice extent (-13.0% per decade). Permafrost temperatures reached record high values in northernmost Alaska. A new melt extent record occurred on 11-12 July on the Greenland ice sheet; 97% of the ice sheet showed some form of melt, four times greater than the average melt for this time of year. The climate in Antarctica was relatively stable overall. The largest maximum sea ice extent since records begain in 1978 was observed in September 2012. In the stratosphere, warm air led to the second smallest ozone hole in the past two decades. Even so, the springtime ozone layer above Antarctica likely will not return to its early 1980s state until about 2060. Following a slight decline associated with the global 2 emissions from fossil fuel combustion and cement production reached a record 9.5 +/- 0.5 Pg C in 2011 and a new record of 9.7 +/- 0.5 Pg C is estimated for 2012. Atmospheric CO2 concentrations increased by 2.1 ppm in 2012, to 392.6 ppm. In spring 2012, 2 concentration exceeded 400 ppm at 7 of the 13 Arctic observation sites. Globally, other greenhouse gases including methane and nitrous oxide also continued to rise in concentration and the combined effect now represents a 32% increase in radiative forcing over a 1990 baseline. Concentrations of most ozone depleting substances continued to fall.
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| 6. |
- Boyero, Luz, et al.
(författare)
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Riparian plant litter quality increases with latitude
- 2017
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Plant litter represents a major basal resource in streams, where its decomposition is partly regulated by litter traits. Litter-trait variation may determine the latitudinal gradient in decomposition in streams, which is mainly microbial in the tropics and detritivore-mediated at high latitudes. However, this hypothesis remains untested, as we lack information on large-scale trait variation for riparian litter. Variation cannot easily be inferred from existing leaf-trait databases, since nutrient resorption can cause traits of litter and green leaves to diverge. Here we present the first global-scale assessment of riparian litter quality by determining latitudinal variation (spanning 107 degrees) in litter traits (nutrient concentrations; physical and chemical defences) of 151 species from 24 regions and their relationships with environmental factors and phylogeny. We hypothesized that litter quality would increase with latitude (despite variation within regions) and traits would be correlated to produce 'syndromes' resulting from phylogeny and environmental variation. We found lower litter quality and higher nitrogen: phosphorus ratios in the tropics. Traits were linked but showed no phylogenetic signal, suggesting that syndromes were environmentally determined. Poorer litter quality and greater phosphorus limitation towards the equator may restrict detritivore-mediated decomposition, contributing to the predominance of microbial decomposers in tropical streams.
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| 7. |
- 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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| 8. |
- Hudson, Lawrence N, et al.
(författare)
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The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project
- 2017
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Ingår i: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 7:1, s. 145-188
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Tidskriftsartikel (refereegranskat)abstract
- The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
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| 9. |
- 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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| 10. |
- 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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| 11. |
- Thorell, Kaisa, 1983, et al.
(författare)
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The Helicobacter pylori Genome Project: insights into H. pylori population structure from analysis of a worldwide collection of complete genomes
- 2023
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Ingår i: Nature Communications. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics.
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| 12. |
- Weinstein, John N., et al.
(författare)
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The cancer genome atlas pan-cancer analysis project
- 2013
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 45:10, s. 1113-1120
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Forskningsöversikt (refereegranskat)abstract
- The Cancer Genome Atlas (TCGA) Research Network has profiled and analyzed large numbers of human tumors to discover molecular aberrations at the DNA, RNA, protein and epigenetic levels. The resulting rich data provide a major opportunity to develop an integrated picture of commonalities, differences and emergent themes across tumor lineages. The Pan-Cancer initiative compares the first 12 tumor types profiled by TCGA. Analysis of the molecular aberrations and their functional roles across tumor types will teach us how to extend therapies effective in one cancer type to others with a similar genomic profile. © 2013 Nature America, Inc. All rights reserved.
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| 13. |
- Arndt, D. S., et al.
(författare)
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State of the Climate in 2016
- 2017
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Ingår i: Bulletin of The American Meteorological Society - (BAMS). - 0003-0007 .- 1520-0477. ; 98:8, s. S1-S280
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Tidskriftsartikel (refereegranskat)abstract
- In 2016, the dominant greenhouse gases released into Earth's atmosphere-carbon dioxide, methane, and nitrous oxide-continued to increase and reach new record highs. The 3.5 +/- 0.1 ppm rise in global annual mean carbon dioxide from 2015 to 2016 was the largest annual increase observed in the 58-year measurement record. The annual global average carbon dioxide concentration at Earth's surface surpassed 400 ppm (402.9 +/- 0.1 ppm) for the first time in the modern atmospheric measurement record and in ice core records dating back as far as 800000 years. One of the strongest El Nino events since at least 1950 dissipated in spring, and a weak La Nina evolved later in the year. Owing at least in part to the combination of El Nino conditions early in the year and a long-term upward trend, Earth's surface observed record warmth for a third consecutive year, albeit by a much slimmer margin than by which that record was set in 2015. Above Earth's surface, the annual lower troposphere temperature was record high according to all datasets analyzed, while the lower stratospheric temperature was record low according to most of the in situ and satellite datasets. Several countries, including Mexico and India, reported record high annual temperatures while many others observed near-record highs. A week-long heat wave at the end of April over the northern and eastern Indian peninsula, with temperatures surpassing 44 degrees C, contributed to a water crisis for 330 million people and to 300 fatalities. In the Arctic the 2016 land surface temperature was 2.0 degrees C above the 1981-2010 average, breaking the previous record of 2007, 2011, and 2015 by 0.8 degrees C, representing a 3.5 degrees C increase since the record began in 1900. The increasing temperatures have led to decreasing Arctic sea ice extent and thickness. On 24 March, the sea ice extent at the end of the growth season saw its lowest maximum in the 37-year satellite record, tying with 2015 at 7.2% below the 1981-2010 average. The September 2016 Arctic sea ice minimum extent tied with 2007 for the second lowest value on record, 33% lower than the 1981-2010 average. Arctic sea ice cover remains relatively young and thin, making it vulnerable to continued extensive melt. The mass of the Greenland Ice Sheet, which has the capacity to contribute similar to 7 m to sea level rise, reached a record low value. The onset of its surface melt was the second earliest, after 2012, in the 37-year satellite record. Sea surface temperature was record high at the global scale, surpassing the previous record of 2015 by about 0.01 degrees C. The global sea surface temperature trend for the 21st century-to-date of +0.162 degrees C decade(-1) is much higher than the longer term 1950-2016 trend of +0.100 degrees C decade(-1). Global annual mean sea level also reached a new record high, marking the sixth consecutive year of increase. Global annual ocean heat content saw a slight drop compared to the record high in 2015. Alpine glacier retreat continued around the globe, and preliminary data indicate that 2016 is the 37th consecutive year of negative annual mass balance. Across the Northern Hemisphere, snow cover for each month from February to June was among its four least extensive in the 47-year satellite record. Continuing a pattern below the surface, record high temperatures at 20-m depth were measured at all permafrost observatories on the North Slope of Alaska and at the Canadian observatory on northernmost Ellesmere Island. In the Antarctic, record low monthly surface pressures were broken at many stations, with the southern annular mode setting record high index values in March and June. Monthly high surface pressure records for August and November were set at several stations. During this period, record low daily and monthly sea ice extents were observed, with the November mean sea ice extent more than 5 standard deviations below the 1981-2010 average. These record low sea ice values contrast sharply with the record high values observed during 2012-14. Over the region, springtime Antarctic stratospheric ozone depletion was less severe relative to the 1991-2006 average, but ozone levels were still low compared to pre-1990 levels. Closer to the equator, 93 named tropical storms were observed during 2016, above the 1981-2010 average of 82, but fewer than the 101 storms recorded in 2015. Three basins-the North Atlantic, and eastern and western North Pacific-experienced above-normal activity in 2016. The Australian basin recorded its least active season since the beginning of the satellite era in 1970. Overall, four tropical cyclones reached the Saffir-Simpson category 5 intensity level. The strong El Nino at the beginning of the year that transitioned to a weak La Nina contributed to enhanced precipitation variability around the world. Wet conditions were observed throughout the year across southern South America, causing repeated heavy flooding in Argentina, Paraguay, and Uruguay. Wetter-than-usual conditions were also observed for eastern Europe and central Asia, alleviating the drought conditions of 2014 and 2015 in southern Russia. In the United States, California had its first wetter-than-average year since 2012, after being plagued by drought for several years. Even so, the area covered by drought in 2016 at the global scale was among the largest in the post-1950 record. For each month, at least 12% of land surfaces experienced severe drought conditions or worse, the longest such stretch in the record. In northeastern Brazil, drought conditions were observed for the fifth consecutive year, making this the longest drought on record in the region. Dry conditions were also observed in western Bolivia and Peru; it was Bolivia's worst drought in the past 25 years. In May, with abnormally warm and dry conditions already prevailing over western Canada for about a year, the human-induced Fort McMurray wildfire burned nearly 590000 hectares and became the costliest disaster in Canadian history, with $3 billion (U.S. dollars) in insured losses.
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| 14. |
- Benavides, Raquel, et al.
(författare)
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The GenTree Leaf Collection : Inter- and intraspecific leaf variation in seven forest tree species in Europe
- 2021
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Ingår i: Global Ecology and Biogeography. - : John Wiley & Sons. - 1466-822X .- 1466-8238. ; 30:3, s. 590-597
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Tidskriftsartikel (refereegranskat)abstract
- Motivation Trait variation within species can reveal plastic and/or genetic responses to environmental gradients, and may indicate where local adaptation has occurred. Here, we present a dataset of rangewide variation in leaf traits from seven of the most ecologically and economically important tree species in Europe. Sample collection and trait assessment are embedded in the GenTree project (EU-Horizon 2020), which aims at characterizing the genetic and phenotypic variability of forest tree species to optimize the management and sustainable use of forest genetic resources. Our dataset captures substantial intra- and interspecific leaf phenotypic variability, and provides valuable information for studying the relationship between ecosystem functioning and trait variability of individuals, and the response and resilience of species to environmental changes. Main types of variable contained We chose morphological and chemical characters linked to trade-offs between acquisition and conservation of resources and water use, namely specific leaf area, leaf size, carbon and nitrogen content and their ratio, and the isotopic signature of stable isotope C-13 and N-15 in leaves. Spatial location and grain We surveyed between 18 and 22 populations per species, 141 in total, across Europe. Time period Leaf sampling took place between 2016 and 2017. Major taxa and level of measurement We sampled at least 25 individuals in each population, 3,569 trees in total, and measured traits in 35,755 leaves from seven European tree species, i.e. the conifers Picea abies, Pinus pinaster and Pinus sylvestris, and the broadleaves Betula pendula, Fagus sylvatica, Populus nigra and Quercus petraea. Software format The data files are in ASCII text, tab delimited, not compressed.
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| 15. |
- Dufresnes, Christophe, et al.
(författare)
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Fifteen shades of green : The evolution of Bufotes toads revisited
- 2019
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Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 141
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Tidskriftsartikel (refereegranskat)abstract
- The radiation of Palearctic green toads (Bufotes) holds great potential to evaluate the role of hybridization in phylogeography at multiple stages along the speciation continuum. With fifteen species representing three ploidy levels, this model system is particularly attractive to examine the causes and consequences of allopoly-ploidization, a prevalent yet enigmatic pathway towards hybrid speciation. Despite substantial efforts, the evolutionary history of this species complex remains largely blurred by the lack of consistency among the corresponding literature. To get a fresh, comprehensive view on Bufotes phylogeography, here we combined genome-wide multilocus analyses (RAD-seq) with an extensive compilation of mitochondrial, genome size, niche modelling, distribution and phenotypic (bioacoustics, morphometrics, toxin composition) datasets, representing hundreds of populations throughout Eurasia. We provide a fully resolved nuclear phylogeny for Bufotes and highlight exceptional cyto-nuclear discordances characteristic of complete mtDNA replacement (in 20% of species), mitochondrial surfing during post-glacial expansions, and the formation of homoploid hybrid populations. Moreover, we traced the origin of several allopolyploids down to species level, showing that all were exclusively fathered by the West Himalayan B. latastii but mothered by several diploid forms inhabiting Central Asian lowlands, an asymmetry consistent with hypotheses on mate choice and Dobzhansky-Muller incompatibilities. Their intermediate call phenotypes potentially allowed for rapid reproductive isolation, while toxin compositions converged towards the ecologically-closest parent. Across the radiation, we pinpoint a stepwise progression of reproductive isolation through time, with a threshold below which hybridizability is irrespective of divergence (< 6My), above which species barely admix and eventually evolve different mating calls (6-10My), or can successfully cross-breed through allopolyploidization (> 15My). Finally, we clarified the taxonomy of Bufotes (including genetic analyses of type series) and formally described two new species, B. cypriensis sp. nov. (endemic to Cyprus) and B. perrini sp. nov. (endemic to Central Asia). Embracing the genomic age, our framework marks the advent of a new exciting era for evolutionary research in these iconic amphibians.
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| 16. |
- Edwards, Robert A., et al.
(författare)
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Global phylogeography and ancient evolution of the widespread human gut virus crAssphage
- 2019
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Ingår i: Nature Microbiology. - : Springer Science and Business Media LLC. - 2058-5276. ; 4:10, s. 1727-1736
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Tidskriftsartikel (refereegranskat)abstract
- Microbiomes are vast communities of microorganisms and viruses that populate all natural ecosystems. Viruses have been considered to be the most variable component of microbiomes, as supported by virome surveys and examples of high genomic mosaicism. However, recent evidence suggests that the human gut virome is remarkably stable compared with that of other environments. Here, we investigate the origin, evolution and epidemiology of crAssphage, a widespread human gut virus. Through a global collaboration, we obtained DNA sequences of crAssphage from more than one-third of the world's countries and showed that the phylogeography of crAssphage is locally clustered within countries, cities and individuals. We also found fully colinear crAssphage-like genomes in both Old-World and New-World primates, suggesting that the association of crAssphage with primates may be millions of years old. Finally, by exploiting a large cohort of more than 1,000 individuals, we tested whether crAssphage is associated with bacterial taxonomic groups of the gut microbiome, diverse human health parameters and a wide range of dietary factors. We identified strong correlations with different clades of bacteria that are related to Bacteroidetes and weak associations with several diet categories, but no significant association with health or disease. We conclude that crAssphage is a benign cosmopolitan virus that may have coevolved with the human lineage and is an integral part of the normal human gut virome.
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| 17. |
- Frede, Annika, et al.
(författare)
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B cell expansion hinders the stroma-epithelium regenerative cross talk during mucosal healing
- 2022
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Ingår i: Immunity. - : Elsevier BV. - 1074-7613 .- 1097-4180. ; 55:12, s. 2336-
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Tidskriftsartikel (refereegranskat)abstract
- Therapeutic promotion of intestinal regeneration holds great promise, but defining the cellular mechanisms that influence tissue regeneration remains an unmet challenge. To gain insight into the process of mucosal healing, we longitudinally examined the immune cell composition during intestinal damage and regeneration. B cells were the dominant cell type in the healing colon, and single-cell RNA sequencing (scRNA-seq) re-vealed expansion of an IFN-induced B cell subset during experimental mucosal healing that predominantly located in damaged areas and associated with colitis severity. B cell depletion accelerated recovery upon injury, decreased epithelial ulceration, and enhanced gene expression programs associated with tissue re-modeling. scRNA-seq from the epithelial and stromal compartments combined with spatial transcriptomics and multiplex immunostaining showed that B cells decreased interactions between stromal and epithelial cells during mucosal healing. Activated B cells disrupted the epithelial-stromal cross talk required for orga-noid survival. Thus, B cell expansion during injury impairs epithelial-stromal cell interactions required for mucosal healing, with implications for the treatment of IBD.
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| 18. |
- Jonsén, Pär, 1971-, et al.
(författare)
-
A Novel Method for Modelling of Cold Cutting of Microstructurally Tailored Hot Formed Components
- 2019
-
Ingår i: Hot sheet metal forming of high-performance steel. - : Wissenschaftliche Scripten. ; , s. 645-652
-
Konferensbidrag (refereegranskat)abstract
- In the last decade, hot metal forming of advanced high strength steel (AHSS) have improved passenger safety and open possibilities for lightweight design. Hot metal forming can be applied to locally tailor the microstructure of components and gradual vary mechanical properties to improve crash resistance behaviour and optimized weight for e.g. safety related parts. Sometimes post punching or trimming must be done on hardened parts. Such conditions induce damage and fractures in the trimmed edge. Another issue is that high pressures are required in cutting operations due to the high yield stress of press hardened parts, which accelerate wear and produce premature fracture in tools. Optimizing cutting operations to minimize damage and wear are essentials and numerical simulations of cutting operations can be of good assistance. One of the main challenges in the numerical modelling consists of numerically be able to treat the extremely large deformation occurring in the cutting zone. A second challenge is to find suitable failure models. In this work, the punching process of soft and hard microstructures obtained by press hardening is experimentally studied, but also modelled with a combination of smoothed particle Galerkin (SPG) method and finite element method (FEM). Laboratory punching tests with different clearance values were carried out using sheets of different fracture strengths. All experimental cases are numerically modelled. Validation is conducted by comparing numerical results with experimental measurements of punch force and displacement. In addition, morphology of the final cutting edges from both real and virtual are compared. Numerical results show good agreement against experimental measurements. Furthermore, the combined method gives robust-ness and stability as it can handle large deformations efficiently.
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| 19. |
- Lara-Ramirez, Ricardo, et al.
(författare)
-
A Notch-regulated proliferative stem cell zone in the developing spinal cord is an ancestral vertebrate trait
- 2019
-
Ingår i: Development. - : Company of Biologists. - 0950-1991 .- 1477-9129. ; 146:1
-
Tidskriftsartikel (refereegranskat)abstract
- Vertebrates have evolved the most sophisticated nervous systems we know. These differ from the nervous systems of invertebrates in several ways, including the evolution of new cell types, and the emergence and elaboration of patterning mechanisms to organise cells in time and space. Vertebrates also generally have many more cells in their central nervous systems than invertebrates, and an increase in neural cell number may have contributed to the sophisticated anatomy of the brain and spinal cord. Here, we study how increased cell number evolved in the vertebrate central nervous system, investigating the regulation of cell proliferation in the lamprey spinal cord. Markers of proliferation show that a ventricular progenitor zone is found throughout the lamprey spinal cord. We show that inhibition of Notch signalling disrupts the maintenance of this zone. When Notch is blocked, progenitor cells differentiate precociously, the proliferative ventricular zone is lost and differentiation markers become expressed throughout the spinal cord. Comparison with other chordates suggests that the emergence of a persistent Notch-regulated proliferative progenitor zone was a crucial step for the evolution of vertebrate spinal cord complexity.
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| 20. |
- Lara-Ramirez, Ricardo, et al.
(författare)
-
Characterization of two neurogenin genes from the brook lamprey lampetra planeri and their expression in the lamprey nervous system
- 2015
-
Ingår i: Developmental Dynamics. - : Wiley. - 1058-8388 .- 1097-0177. ; 244:9, s. 1096-1108
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Neurogenins are required for the specification of neuronal precursors and regulate the expression of basic Helix-Loop-Helix genes involved in neuronal differentiation. Jawed vertebrates possess three Neurogenin paralogy groups and their combined expression covers the entire nervous system, apart from the autonomic nervous system. Results: Here we report the isolation of two Neurogenin genes, LpNgnA and LpNgnB, from the lamprey Lampetra planeri. Phylogenetic analyses show both genes have orthologues in other lamprey species and in a hagfish. Neither gene shows evidence of orthology to specific jawed vertebrate Neurogenin paralogues. LpNgnA is expressed in the ventricular zone of regions of the brain and spinal cord, with expression in the brain demarcating brain sub-compartments including the pallium, tegmentum, tectum, and dorsal thalamus. In the peripheral nervous system, LpNgnA is expressed in cranial sensory placodes and their derivatives, and in the dorsal root ganglia. LpNgnB is expressed transiently in placodal head ectoderm and throughout the central nervous system in early development, and in a small population cells that form part of the macula. Conclusions: Combined, LpNgnA and LpNgnB were detected in most cell populations marked by Neurogenin gene expression in jawed vertebrates, with the exception of the cerebellum, retina and the non-neural expression sites. (c) 2015 Wiley Periodicals, Inc.
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| 21. |
- Lara-Ramirez, Ricardo, et al.
(författare)
-
The structure, splicing, synteny and expression of lamprey COE genes and the evolution of the COE gene family in chordates
- 2017
-
Ingår i: Development, Genes and Evolution. - : SPRINGER. - 0949-944X .- 1432-041X. ; 227:5, s. 319-338
-
Tidskriftsartikel (refereegranskat)abstract
- COE genes encode transcription factors that have been found in all metazoans examined to date. They possess a distinctive domain structure that includes a DNA-binding domain (DBD), an IPT/TIG domain and a helix-loop-helix (HLH) domain. An intriguing feature of the COE HLH domain is that in jawed vertebrates it is composed of three helices, compared to two in invertebrates. We report the isolation and expression of two COE genes from the brook lamprey Lampetra planeri and compare these to COE genes from the lampreys Lethenteron japonicum and Petromyzon marinus. Molecular phylogenetic analyses do not resolve the relationship of lamprey COE genes to jawed vertebrate paralogues, though synteny mapping shows that they all derive from duplication of a common ancestral genomic region. All lamprey genes encode conserved DBD, IPT/TIG and HLH domains; however, the HLH domain of lamprey COE-A genes encodes only two helices while COE-B encodes three helices. We also identified COE-B splice variants encoding either two or three helices in the HLH domain, along with other COE-A and COE-B splice variants affecting the DBD and C-terminal transactivation regions. In situ hybridisation revealed expression in the lamprey nervous system including the brain, spinal cord and cranial sensory ganglia. We also detected expression of both genes in mesenchyme in the pharyngeal arches and underlying the notochord. This allows us to establish the primitive vertebrate expression pattern for COE genes and compare this to that of invertebrate chordates and other animals to develop a model for COE gene evolution in chordates.
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| 22. |
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| 23. |
- Lidberg, Tina, et al.
(författare)
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An approach to illustrate strategies for improved energy efficiency at the municipal level
- 2014
-
Ingår i: Proceedings from the 14th International Symposium on District Heating and Cooling. - 9789185775248 ; , s. 50-55
-
Konferensbidrag (refereegranskat)abstract
- This work focuses on how implementation of wellknown refurbishment strategies, applied on multifamily buildings in a post-war housing complex in Sweden can affect the generation of district heating. Both the energy use and the power load were considered.The study was performed in Borlänge municipality, Sweden, where the municipality owns both the energy and the housing companies. The strategies for energy efficiency were simulated with IDA-ICE for the Tjärna Ängar area, a housing complex built between 1969- 1971, with access to documented information about the buildings and energy audit. The results of the building simulation were implemented in a simplified model of the local district heating system.The results indicate how different renovation strategies affect the demand of energy and power load within the district heating system and can be used to provide indicators for different scenarios. The larger goal of the research is how to maximize the economic and environmental efficiency of improvement strategies on a municipal level as well as how to find appropriate energy optimization methods that can be proposed by building contractors. The initial study presented here was conducted within the research program Reesbe.
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| 24. |
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| 25. |
- Martinez-Sancho, Elisabet, et al.
(författare)
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The GenTree Dendroecological Collection, tree-ring and wood density data from seven tree species across Europe
- 2020
-
Ingår i: Scientific Data. - : NATURE PUBLISHING GROUP. - 2052-4463. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- The dataset presented here was collected by the GenTree project (EU-Horizon 2020), which aims to improve the use of forest genetic resources across Europe by better understanding how trees adapt to their local environment. This dataset of individual tree-core characteristics including ring-width series and whole-core wood density was collected for seven ecologically and economically important European tree species: silver birch (Betula pendula), European beech (Fagus sylvatica), Norway spruce (Picea abies), European black poplar (Populus nigra), maritime pine (Pinus pinaster), Scots pine (Pinus sylvestris), and sessile oak (Quercus petraea). Tree-ring width measurements were obtained from 3600 trees in 142 populations and whole-core wood density was measured for 3098 trees in 125 populations. This dataset covers most of the geographical and climatic range occupied by the selected species. The potential use of it will be highly valuable for assessing ecological and evolutionary responses to environmental conditions as well as for model development and parameterization, to predict adaptability under climate change scenarios.
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| 26. |
- Massart, Annick, et al.
(författare)
-
The DESCARTES-Nantes survey of kidney transplant recipients displaying clinical operational tolerance identifies 35 new tolerant patients and 34 almost tolerant patients
- 2016
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Ingår i: Nephrology, Dialysis and Transplantation. - : Oxford University Press (OUP). - 0931-0509 .- 1460-2385. ; 31:6, s. 1002-1013
-
Tidskriftsartikel (refereegranskat)abstract
- Background. Kidney recipients maintaining a prolonged allograft survival in the absence of immunosuppressive drugs and without evidence of rejection are supposed to be exceptional. The ERA-EDTA-DESCARTES working group together with Nantes University launched a European-wide survey to identify new patients, describe them and estimate their frequency for the first time. Methods. Seventeen coordinators distributed a questionnaire in 256 transplant centres and 28 countries in order to report as many 'operationally tolerant' patients (TOL; defined as having a serum creatinine <1.7 mg/dL and proteinuria <1 g/day or g/g creatinine despite at least 1 year without any immunosuppressive drug) and 'almost tolerant' patients (minimally immunosuppressed patients (MIS) receiving low-dose steroids) as possible. We reported their number and the total number of kidney transplants performed at each centre to calculate their frequency. Results. One hundred and forty-seven questionnaires were returned and we identified 66 TOL (61 with complete data) and 34 MIS patients. Of the 61 TOL patients, 26 were previously described by the Nantes group and 35 new patients are presented here. Most of them were noncompliant patients. At data collection, 31/35 patients were alive and 22/31 still operationally tolerant. For the remaining 9/31, 2 were restarted on immunosuppressive drugs and 7 had rising creatinine of whom 3 resumed dialysis. Considering all patients, 10-year death-censored graft survival post-immunosuppression weaning reached 85% in TOL patients and 100% in MIS patients. With 218 913 kidney recipients surveyed, cumulative incidences of operational tolerance and almost tolerance were estimated at 3 and 1.5 per 10 000 kidney recipients, respectively. Conclusions. In kidney transplantation, operational tolerance and almost tolerance are infrequent findings associated with excellent long-term death-censored graft survival.
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| 27. |
- Opgenoorth, Lars, et al.
(författare)
-
The GenTree Platform : growth traits and tree-level environmental data in 12 European forest tree species
- 2021
-
Ingår i: GigaScience. - : Oxford University Press. - 2047-217X. ; 10:3
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Progress in the field of evolutionary forest ecology has been hampered by the huge challenge of phenotyping trees across their ranges in their natural environments, and the limitation in high-resolution environmental information.Findings: The GenTree Platform contains phenotypic and environmental data from 4,959 trees from 12 ecologically and economically important European forest tree species: Abies alba Mill. (silver fir), Betula pendula Roth. (silver birch), Fagus sylvatica L. (European beech), Picea abies (L.) H. Karst (Norway spruce), Pinus cembra L. (Swiss stone pine), Pinus halepensis Mill. (Aleppo pine), Pinus nigra Arnold (European black pine), Pinus pinaster Aiton (maritime pine), Pinus sylvestris L. (Scots pine), Populus nigra L. (European black poplar), Taxus baccata L. (English yew), and Quercus petraea (Matt.) Liebl. (sessile oak). Phenotypic (height, diameter at breast height, crown size, bark thickness, biomass, straightness, forking, branch angle, fructification), regeneration, environmental in situ measurements (soil depth, vegetation cover, competition indices), and environmental modeling data extracted by using bilinear interpolation accounting for surrounding conditions of each tree (precipitation, temperature, insolation, drought indices) were obtained from trees in 194 sites covering the species' geographic ranges and reflecting local environmental gradients.Conclusion: The GenTree Platform is a new resource for investigating ecological and evolutionary processes in forest trees. The coherent phenotyping and environmental characterization across 12 species in their European ranges allow for a wide range of analyses from forest ecologists, conservationists, and macro-ecologists. Also, the data here presented can be linked to the GenTree Dendroecological collection, the GenTree Leaf Trait collection, and the GenTree Genomic collection presented elsewhere, which together build the largest evolutionary forest ecology data collection available.
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| 28. |
- Parigi, Sara M., et al.
(författare)
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The spatial transcriptomic landscape of the healing mouse intestine following damage
- 2022
-
Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- The colon is comprised of specialized cells that interact with each other to function, however, the molecular regionalization of the colon is incompletely understood. Here, the authors use spatial transcriptomics to generate a publicly available resource defining the transcriptomic regionalization of the colon during steady state and mucosal healing. The intestinal barrier is composed of a complex cell network defining highly compartmentalized and specialized structures. Here, we use spatial transcriptomics to define how the transcriptomic landscape is spatially organized in the steady state and healing murine colon. At steady state conditions, we demonstrate a previously unappreciated molecular regionalization of the colon, which dramatically changes during mucosal healing. Here, we identified spatially-organized transcriptional programs defining compartmentalized mucosal healing, and regions with dominant wired pathways. Furthermore, we showed that decreased p53 activation defined areas with increased presence of proliferating epithelial stem cells. Finally, we mapped transcriptomics modules associated with human diseases demonstrating the translational potential of our dataset. Overall, we provide a publicly available resource defining principles of transcriptomic regionalization of the colon during mucosal healing and a framework to develop and progress further hypotheses.
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| 29. |
- Prus, C., et al.
(författare)
-
Impact simulation and optimisation of elastic fuel tanks reinforced with exoskeleton for aerospace applications
- 2017
-
Ingår i: International Journal of Crashworthiness. - : Taylor & Francis. - 1358-8265 .- 1754-2111. ; 22:3, s. 271-293
-
Tidskriftsartikel (refereegranskat)abstract
- The main subject of the study is the impact simulation of an elastic fuel tank reinforced with a polymer exoskeleton. Thanks to its lightweight and failure resistance, this type of design shows potential to be used in aerospace applications. The simulation emulates a drop test from the height of 20 m on a rigid surface, in accordance with Military Handbook testing guidelines for fuel tanks. The focus is on providing an example of modelling and solving this type of problems. The computational methods are tested on a generic model of a rectangular prismatic tank with rounded edges. The walls of the tank are made of orthotropic fabric reinforced polymer. The simulation is performed for a 70% and a 100% water-filled tank. All calculations are performed using the Altair HyperWorks 13.0 software suite, in particular, the nonlinear RADIOSS solver and OptiStruct Solver and Optimiser. The fluid inside the tank is modelled using the SPH (Smoothed Particle Hydrodynamics) approach. The model serves as a basis for establishing a design optimisation procedure, aiming at reduction of mass of the tank components while ensuring structural integrity. The main insights of the current study are the successful modelling of the liquid and the air inside the tank by means of smoothed-particle hydrodynamics elements, and the structural optimisation methodology of a composite fuel tank.
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| 30. |
- Quarry, Wendy, et al.
(författare)
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Two practitioners look 10-years back (A Reflection)
- 2015
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Ingår i: Glocal Times. - : Malmö university, Communication for Development. - 1654-7985. ; :22/23
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We met in 1984 during a “Methods & Media in Community Development” gathering in Labrador, Canada, an event, organized by Andreas Fuglesang and Dale Chandler with the Dag Hammarskjöld Foundation in Sweden. Here we came across practitioner- champions from around the world who were using media to engage with people in exciting ways. A decade later, we reconnected and collaborated through some FAO work in Pakistan. Since then we have continued our practice working together on various communication strategies, much shared writing, our never-ending Skypes, and our disagreements… How else can one work as a team?
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| 31. |
- Ramírez, Jaime A., et al.
(författare)
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Aportes a la Teoría y la Implementación del Método LSCR
- 2010
-
Ingår i: RIAI - Revista Iberoamericana de Automatica e Informatica Industrial. - 1697-7912. ; 7:3, s. 83-94
-
Tidskriftsartikel (refereegranskat)abstract
- The LSCR method (Leave-out-Sign-dominant-Correlation-Regions) provides confidence regions for the parameters of a system by evaluating a set of correlation functions calculated for the available data. To do the approximation for the whole region, the procedure must be repeated for each value of the parameter vector. The main attributes of LSCR are its validity for a finite set of data and the scarce assumptions on the noise. However, the procedure needs much computational effort, which limits its application to very simple cases. In this work some theoretical aspects of the LSCR method are improved and some implementation alternatives are suggested. It is also compared, in terms of computational effort, with Bootstrap, another way to obtain confidence regions.
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| 32. |
- Ramirez Villegas, Ricardo
(författare)
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A methodology to assess impacts of energy efficient renovation : a Swedish case study
- 2017
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The European Union aims to reduce energy use and CO2-emissions by 40 % by the year 2030. The building sector has been identified as having a great potential to reduce emission of CO2 by increasing its energy efficiency. Also, there is a growing concern of the buildings environmental performance, that lead to the development of building environmental assessment tools. However, different types of energy sources and confusing environmental impacts affect the decision making when renovating for improved energy efficiency. This study develops and tests a methodology to help decision-makers when considering major renovation of their building stock when connected to adistrict heating system. The proposed methodology is applied and used to investigate how different renovation scenarios affects the building environmental impacts in terms of CO2 emissions and identify and discuss future improvements of the methodology.The novelty of the method is the expanded system boundaries that include both the distribution and production of district heating and the energy use at a building level. In this way it is possible to compare and weight measures made both at the energy system level and the building level. This work has limited its approach to energy use in buildings, but it is important to bring the life cycle thinking to the methodology. During the choice of the renovation methods it was noticed that the environmental impact of the production of some components in order to reduce the energy use of a building are not insignificant. Even if all the renovation measures considered in this case study are feasible, it is important to determine in which order they are desirable or achievable from an economic point of view. Uncertainty in the future development of energy, and limited economic resources can play an important role in the possibility of energy efficient renovation.
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| 33. |
- Ramírez Villegas, Ricardo, et al.
(författare)
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Assessment of renovation measures for a dwelling area : impacts on energy efficiency and building certification
- 2016
-
Ingår i: Building and Environment. - : Elsevier BV. - 0360-1323 .- 1873-684X. ; 97, s. 26-33
-
Tidskriftsartikel (refereegranskat)abstract
- The European Union has an ambitious plan to reduce energy use and emissions by the year 2030. The building and real estate sectors have a great potential to help reduce emissions by energy efficiency. However, different energy sources and environmental standards affect the decision making of these major renovations in the existing stock. This study investigates how different renovation strategies affect the energy rating of a selected Building Environmental Assessment Tool and analyses the consequences in terms of greenhouse gas emissions for the local district heating system. Both building energy simulations and energy systems cost optimization were used to determine the energy use and local emissions. The results of different renovation scenarios were used to evaluate the rating in the selected tool and the impact in the district heating local emissions. The used methodology illustrates how energy efficient renovation impacts on the district heating system’s local emissions. However, a bias towards resource classification within the Swedish Building Environmental Tool, Miljöbyggnad, needs to be addressed in order to assess the impact of local emissions. © 2015 Elsevier Ltd.
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| 34. |
- Ramírez Villegas, Ricardo, 1981-, et al.
(författare)
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Combined environmental and economic assessment of energy efficiency measures in a multi-dwelling building
- 2019
-
Ingår i: Energies. - : MDPI AG. - 1996-1073. ; 12:13
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study is to assess how different renovation scenarios affect the environmental and economic impacts of a multi-dwelling building in a Nordic climate, how these aspects are correlated and how different energy carriers affect different environmental impact categories. In order to reduce greenhouse gas emissions, the European Union has set an agenda in order to reduce energy use in buildings. New buildings on the European market have a low replacement rate, which makes building renovation an important factor for achieving the European Union goals. In this study, eight renovation strategies were analyzed following the European Committee for Standardization standards for life cycle assessment and life cycle costs of buildings. This study covers all life cycle steps from cradle to grave. The renovation scenarios include combinations of photovoltaics, geothermal heat pumps, heat recovery ventilation and improved building envelopes. Results show that, depending on the energy carrier, reductions in global warming potential can be achieved at the expense of an increased nuclear waste disposal. It also shows that for the investigated renovation strategies in Sweden there is no correlation between the economic and the environmental performance of the building. Changing energy carriers in Sweden in order to reduce greenhouse gas emissions can be a good alternative, but it makes the system more dependent on nuclear power.
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| 35. |
- Ramirez Villegas, Ricardo, 1981-
(författare)
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Energy efficient renovation in a life cycle perspective : A case study of a Swedish multifamily-building
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Energy use in the European Union is increasing. At the same time, it is estimated that by the year 2050 most of the EU population will be living in currently existing buildings. Some of these buildings are or will be in need of renovation, and they have identified a target to reduce overall energy use. The urgency of climate change also makes it highly relevant and important to improve buildings resource and energy efficiency. This thesis aims to explain how different proposed energy efficient renovation strategies affect the energy use at different system levels, the potential environmental impacts of these alternatives, how they are connected to economic impacts and the implications of using a commercial LCA software to answer these questions from a research perspective.In order to answer the questions above, the effect of different renovation strategies were studied by combining building energy simulations, energy system simulations, a building environmental assessment tool, life cycle assessment and life cycle cost calculations. These tools are used in order to provide an overview of how the different renovation strategies affect the production of district heating, greenhouse gas (GHG) emissions and the environmental and economic performance of the building.The results show that the selected renovation strategies reduce energy use by decreasing transmission losses, while reducing the total amount of purchased energy by using solar energy or by changing energy carriers. These different approaches have the potential to reduce the environmental impact, mainly by reducing global warming potential, acidification potential and eutrophication potential and to some extent abiotic depletion potential. However, when changing energy carriers there is a burden shift to radioactive waste disposed. When the economic aspects are analyzed, it is shown that there is no simple correlation between financial and environmental impacts.To analyze a building from a life cycle perspective can help to identify the advantages and disadvantages of energy efficient renovation from the building owner’s perspective as well as from a societal perspective. Applying a life cycle perspective is therefore important for building owners, building companies and practitioners as well for policy makers to avoid suboptimisation.
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| 36. |
- Ramirez Villegas, Ricardo, et al.
(författare)
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Environmental payback of renovation strategies in a northern climate - the impact of nuclear power and fossil fuels in the electricity supply
- 2020
-
Ingår i: Energies. - : MDPI. - 1996-1073. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study is to assess how the use of fossil and nuclear power in different renovation scenarios affects the environmental impacts of a multi-family dwelling in Sweden, and how changes in the electricity production with different energy carriers affect the environmental impact. In line with the Paris Agreement, the European Union has set an agenda to reduce greenhouse gas emissions by means of energy efficiency in buildings. It is estimated that by the year 2050, 80% of Europe's population will be living in buildings that already exist. This means it is important for the European Union to renovate buildings to improve energy efficiency. In this study, eight renovation scenarios, using six different Northern European electricity mixes, were analyzed using the standard of the European Committee for Standardization for life cycle assessment of buildings. This study covers all life cycle steps from cradle to grave. The renovation scenarios include combinations of photovoltaics, geothermal heat pumps, heat recovery ventilation, and improvement of the building envelope. The results show that while in some electricity mixes a reduction in the global warming potential can be achieved, it can be at the expense of an increase in radioactive waste production, and, in mixes with a high share of fossil fuels, the global warming potential of the scenarios increases with time, compared with that of the original building. It also shows that in most electricity mixes, scenarios that reduce the active heat demand of the building end up in reducing both the global warming potential and radioactive waste, making them less sensitive to changes in the energy system.
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| 37. |
- Ramirez Villegas, Ricardo, et al.
(författare)
-
Life Cycle Assessment of Building Renovation Measures : Trade-off between Building Materials and Energy
- 2019
-
Ingår i: Energies. - : MDPI. - 1996-1073. ; 12:3
-
Tidskriftsartikel (refereegranskat)abstract
- The scope of this study is to assess how different energy efficient renovation strategies affect the environmental impacts of a multi-family house in a Nordic climate within district heating systems. The European Union has set ambitious targets to reduce energy use and greenhouse gas emissions by the year 2030. There is special attention on reducing the life cycle emissions in the buildings sector. However, the focus has often been on new buildings, although existing buildings represent great potential within the building stock in Europe. In this study, four different renovation scenarios were analyzed with the commercially available life cycle assessment software that follows the European Committee for Standardization (CEN) standard. This study covers all life cycle steps from the cradle to the grave for a residential building in Borlange, Sweden, where renewable energy dominates. The four scenarios included reduced indoor temperature, improved thermal properties of building material components and heat recovery for the ventilation system. One finding is that changing installations gives an environmental impact comparable to renovations that include both ventilation and building facilities. In addition, the life cycle steps that have the greatest environmental impact in all scenarios are the operational energy use and the building and installation processes. Renovation measures had a major impact on energy use due to the cold climate and low solar irradiation in the heating season. An interesting aspect, however, is that the building materials and the construction processes gave a significant amount of environmental impact.
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| 38. |
- Ramirez Villegas, Ricardo, 1981-, et al.
(författare)
-
Sustainable Renovation and Operation of Family Houses for Improved Climate Efficiency
- 2013
-
Ingår i: Proceedings of the 4th International Conference in Sustainability in Energy and Buildings (SEB´12). - Berlin : Springer Berlin/Heidelberg. - 9783642366451 ; , s. 107-117
-
Konferensbidrag (refereegranskat)abstract
- In the developed world the existing stock of houses will provide shelter to the majority of population in the upcoming years. Houses are physical objects that consume material and energy and need to be maintained, repaired and restructured from time to time. In order to fulfill the requirements of the Kyoto Protocol and be comfortable for their inhabitants, the existing stock needs to be renovated. Strong disagreements between different parts of the scientific community and overlapping and contradictory concepts make the definition of sustainable renovation confusing. In this study, therefore, an approach of renovation and operation for higher energy efficiency and lower climate impact has been the main focus. Based on a systems analysis approach, the aim of this work is to evaluate cost and benefits of possible actions and choosing the most energy and cost effective approach of a series of alternatives. With the result of this analysis, a sustainable renovation and operation staircase is proposed. The work found that it is possible to develop a staircase manual for sustainable renovation and operation of family houses that follows a logical step-by-step approach and could result in considerable life cycle reductions in both costs and climate impact. The work also suggests that it is possible for academic experts to develop material in a simpler form and language to reach the public in a more understandable form.
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| 39. |
- Rodriguez, Ricardo, et al.
(författare)
-
50,000 years of genetic uniformity in the critically endangered Iberian lynx
- 2011
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Ingår i: Molecular Ecology. - 0962-1083 .- 1365-294X. ; 20:18, s. 3785-3795
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Tidskriftsartikel (refereegranskat)abstract
- Low genetic diversity in the endangered Iberian lynx, including lack of mitochondrial control region variation, is thought to result from historical or Pleistocene/Holocene population bottlenecks, and to indicate poor long-term viability. We find no variability in control region sequences from 19 Iberian lynx remains from across the Iberian Peninsula and spanning the last 50 000 years. This is best explained by continuously small female effective population size through time. We conclude that low genetic variability in the Iberian lynx is not in itself a threat to long-term viability, and so should not preclude conservation efforts.
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| 40. |
- Stanaway, Jeffrey D., et al.
(författare)
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Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990-2017: A systematic analysis for the Global Burden of Disease Study 2017
- 2018
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Ingår i: The Lancet. - 1474-547X .- 0140-6736. ; 392:10159, s. 1923-1994
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Tidskriftsartikel (refereegranskat)abstract
- Background The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 comparative risk assessment (CRA) is a comprehensive approach to risk factor quantification that offers a useful tool for synthesising evidence on risks and risk-outcome associations. With each annual GBD study, we update the GBD CRA to incorporate improved methods, new risks and risk-outcome pairs, and new data on risk exposure levels and risk- outcome associations. Methods We used the CRA framework developed for previous iterations of GBD to estimate levels and trends in exposure, attributable deaths, and attributable disability-adjusted life-years (DALYs), by age group, sex, year, and location for 84 behavioural, environmental and occupational, and metabolic risks or groups of risks from 1990 to 2017. This study included 476 risk-outcome pairs that met the GBD study criteria for convincing or probable evidence of causation. We extracted relative risk and exposure estimates from 46 749 randomised controlled trials, cohort studies, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. Using the counterfactual scenario of theoretical minimum risk exposure level (TMREL), we estimated the portion of deaths and DALYs that could be attributed to a given risk. We explored the relationship between development and risk exposure by modelling the relationship between the Socio-demographic Index (SDI) and risk-weighted exposure prevalence and estimated expected levels of exposure and risk-attributable burden by SDI. Finally, we explored temporal changes in risk-attributable DALYs by decomposing those changes into six main component drivers of change as follows: (1) population growth; (2) changes in population age structures; (3) changes in exposure to environmental and occupational risks; (4) changes in exposure to behavioural risks; (5) changes in exposure to metabolic risks; and (6) changes due to all other factors, approximated as the risk-deleted death and DALY rates, where the risk-deleted rate is the rate that would be observed had we reduced the exposure levels to the TMREL for all risk factors included in GBD 2017.
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