SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Iversen Peter) ;hsvcat:1"

Sökning: WFRF:(Iversen Peter) > Naturvetenskap

  • Resultat 1-10 av 16
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Kattge, Jens, et al. (författare)
  • TRY plant trait database - enhanced coverage and open access
  • 2020
  • Ingår i: Global Change Biology. - : Wiley-Blackwell. - 1354-1013 .- 1365-2486. ; 26:1, s. 119-188
  • Tidskriftsartikel (refereegranskat)abstract
    • Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.
  •  
2.
  • Björkman, Anne, 1981, et al. (författare)
  • Plant functional trait change across a warming tundra biome
  • 2018
  • Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 562:7725, s. 57-62
  • Tidskriftsartikel (refereegranskat)abstract
    • The tundra is warming more rapidly than any other biome on Earth, and the potential ramifications are far-reaching because of global feedback effects between vegetation and climate. A better understanding of how environmental factors shape plant structure and function is crucial for predicting the consequences of environmental change for ecosystem functioning. Here we explore the biome-wide relationships between temperature, moisture and seven key plant functional traits both across space and over three decades of warming at 117 tundra locations. Spatial temperature–trait relationships were generally strong but soil moisture had a marked influence on the strength and direction of these relationships, highlighting the potentially important influence of changes in water availability on future trait shifts in tundra plant communities. Community height increased with warming across all sites over the past three decades, but other traits lagged far behind predicted rates of change. Our findings highlight the challenge of using space-for-time substitution to predict the functional consequences of future warming and suggest that functions that are tied closely to plant height will experience the most rapid change. They also reveal the strength with which environmental factors shape biotic communities at the coldest extremes of the planet and will help to improve projections of functional changes in tundra ecosystems with climate warming.
  •  
3.
  • Allentoft, Morten E., et al. (författare)
  • Population genomics of post-glacial western Eurasia
  • 2024
  • Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 625:7994, s. 301-311
  • Tidskriftsartikel (refereegranskat)abstract
    • Western Eurasia witnessed several large-scale human migrations during the Holocene1–5. Here, to investigate the cross-continental effects of these migrations, we shotgun-sequenced 317 genomes—mainly from the Mesolithic and Neolithic periods—from across northern and western Eurasia. These were imputed alongside published data to obtain diploid genotypes from more than 1,600 ancient humans. Our analyses revealed a ‘great divide’ genomic boundary extending from the Black Sea to the Baltic. Mesolithic hunter-gatherers were highly genetically differentiated east and west of this zone, and the effect of the neolithization was equally disparate. Large-scale ancestry shifts occurred in the west as farming was introduced, including near-total replacement of hunter-gatherers in many areas, whereas no substantial ancestry shifts happened east of the zone during the same period. Similarly, relatedness decreased in the west from the Neolithic transition onwards, whereas, east of the Urals, relatedness remained high until around 4,000 bp, consistent with the persistence of localized groups of hunter-gatherers. The boundary dissolved when Yamnaya-related ancestry spread across western Eurasia around 5,000 bp, resulting in a second major turnover that reached most parts of Europe within a 1,000-year span. The genetic origin and fate of the Yamnaya have remained elusive, but we show that hunter-gatherers from the Middle Don region contributed ancestry to them. Yamnaya groups later admixed with individuals associated with the Globular Amphora culture before expanding into Europe. Similar turnovers occurred in western Siberia, where we report new genomic data from a ‘Neolithic steppe’ cline spanning the Siberian forest steppe to Lake Baikal. These prehistoric migrations had profound and lasting effects on the genetic diversity of Eurasian populations.
  •  
4.
  • Allentoft, Morten E., et al. (författare)
  • 100 ancient genomes show repeated population turnovers in Neolithic Denmark
  • 2024
  • Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 625, s. 329-337
  • Tidskriftsartikel (refereegranskat)abstract
    • Major migration events in Holocene Eurasia have been characterized genetically at broad regional scales1–4. However, insights into the population dynamics in the contact zones are hampered by a lack of ancient genomic data sampled at high spatiotemporal resolution5–7. Here, to address this, we analysed shotgun-sequenced genomes from 100 skeletons spanning 7,300 years of the Mesolithic period, Neolithic period and Early Bronze Age in Denmark and integrated these with proxies for diet (13C and 15N content), mobility (87Sr/86Sr ratio) and vegetation cover (pollen). We observe that Danish Mesolithic individuals of the Maglemose, Kongemose and Ertebølle cultures form a distinct genetic cluster related to other Western European hunter-gatherers. Despite shifts in material culture they displayed genetic homogeneity from around 10,500 to 5,900 calibrated years before present, when Neolithic farmers with Anatolian-derived ancestry arrived. Although the Neolithic transition was delayed by more than a millennium relative to Central Europe, it was very abrupt and resulted in a population turnover with limited genetic contribution from local hunter-gatherers. The succeeding Neolithic population, associated with the Funnel Beaker culture, persisted for only about 1,000 years before immigrants with eastern Steppe-derived ancestry arrived. This second and equally rapid population replacement gave rise to the Single Grave culture with an ancestry profile more similar to present-day Danes. In our multiproxy dataset, these major demographic events are manifested as parallel shifts in genotype, phenotype, diet and land use.
  •  
5.
  • Margaryan, Ashot, et al. (författare)
  • Population genomics of the Viking world
  • 2020
  • Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 585:7825, s. 390-396
  • Tidskriftsartikel (refereegranskat)abstract
    • The maritime expansion of Scandinavian populations during the Viking Age (about ad 750–1050) was a far-flung transformation in world history1,2. Here we sequenced the genomes of 442 humans from archaeological sites across Europe and Greenland (to a median depth of about 1×) to understand the global influence of this expansion. We find the Viking period involved gene flow into Scandinavia from the south and east. We observe genetic structure within Scandinavia, with diversity hotspots in the south and restricted gene flow within Scandinavia. We find evidence for a major influx of Danish ancestry into England; a Swedish influx into the Baltic; and Norwegian influx into Ireland, Iceland and Greenland. Additionally, we see substantial ancestry from elsewhere in Europe entering Scandinavia during the Viking Age. Our ancient DNA analysis also revealed that a Viking expedition included close family members. By comparing with modern populations, we find that pigmentation-associated loci have undergone strong population differentiation during the past millennium, and trace positively selected loci—including the lactase-persistence allele of LCT and alleles of ANKA that are associated with the immune response—in detail. We conclude that the Viking diaspora was characterized by substantial transregional engagement: distinct populations influenced the genomic makeup of different regions of Europe, and Scandinavia experienced increased contact with the rest of the continent.
  •  
6.
  • Jung, Thomas, et al. (författare)
  • ADVANCING POLAR PREDICTION CAPABILITIES ON DAILY TO SEASONAL TIME SCALES
  • 2016
  • Ingår i: Bulletin of The American Meteorological Society - (BAMS). - 0003-0007 .- 1520-0477. ; 97:9, s. 1631-
  • Tidskriftsartikel (refereegranskat)abstract
    • The polar regions have been attracting more and more attention in recent years, fueled by the perceptible impacts of anthropogenic climate change. Polar climate change provides new opportunities, such as shorter shipping routes between Europe and East Asia, but also new risks such as the potential for industrial accidents or emergencies in ice-covered seas. Here, it is argued that environmental prediction systems for the polar regions are less developed than elsewhere. There are many reasons for this situation, including the polar regions being (historically) lower priority, with fewer in situ observations, and with numerous local physical processes that are less well represented by models. By contrasting the relative importance of different physical processes in polar and lower latitudes, the need for a dedicated polar prediction effort is illustrated. Research priorities are identified that will help to advance environmental polar prediction capabilities. Examples include an improvement of the polar observing system; the use of coupled atmosphere-sea ice-ocean models, even for short-term prediction; and insight into polar-lower latitude linkages and their role for forecasting. Given the enormity of some of the challenges ahead, in a harsh and remote environment such as the polar regions, it is argued that rapid progress will only be possible with a coordinated international effort. More specifically, it is proposed to hold a Year of Polar Prediction (YOPP) from mid-2017 to mid-2019 in which the international research and operational forecasting communites will work together with stakeholders in a period of intensive observing: modeling, prediction, verification, user engagement, and educational activities.
  •  
7.
  • Tyrsted, Christoffer, et al. (författare)
  • In-Situ Synchrotron Radiation Study of Formation and Growth of Crystalline CexZr1-xO2 Nanoparticles Synthesized in Supercritical Water
  • 2010
  • Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 22:5, s. 1814-1820
  • Tidskriftsartikel (refereegranskat)abstract
    • In situ synchrotron powder X-ray diffraction (PXRD) measurements have been conducted to follow the nucleation and growth of crystalline CexZr1-xO2 nanoparticles synthesized in supercritical water with a full substitution variation (x = 0, 0.2, 0.5, 0.8, and 1.0). Direction-dependent growth curves are determined and described using reaction kinetic models. A disctinct change in growth kinetics is observed with increasing cerium content. For x = 0.8 and 1.0 (high cerium content), the growth in initially limited by the surface reaction kinetics, however, at a size of similar to 6 nm, the growth changes and becomes limited by the diffusion of monomers toward the surface. For x = 0 and 0.2, the opposite behavior is observed with the growth initially being limited by diffusion (up to similar to 3.5 nm) and later by the surface reaction kinetics. Thus, although a continuous solid solution can be obtained for the ceria-zirconia system, the growth of ceria and zirconia nanoparticles is fundamentally different under supercritical flow reactor. The resulting samples were analyzed using PXRD, small-angle X-ray scattering (SAXS), and transmission electron microscopy (TEM). The nanoparticles with x = 0, 0.2, and 0.5 have very low polydispersities. The sizes range from 4 nm to 7 nm, and the particles exhibit a reversibly pH-dependent agglomeration.
  •  
8.
  • Kulmala, M., et al. (författare)
  • General overview: European Integrated project on Aerosol Cloud Climate and Air Quality interactions (EUCAARI) - integrating aerosol research from nano to global scales
  • 2011
  • Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 11:24, s. 13061-13143
  • Tidskriftsartikel (refereegranskat)abstract
    • In this paper we describe and summarize the main achievements of the European Aerosol Cloud Climate and Air Quality Interactions project (EUCAARI). EUCAARI started on 1 January 2007 and ended on 31 December 2010 leaving a rich legacy including: (a) a comprehensive database with a year of observations of the physical, chemical and optical properties of aerosol particles over Europe, (b) comprehensive aerosol measurements in four developing countries, (c) a database of airborne measurements of aerosols and clouds over Europe during May 2008, (d) comprehensive modeling tools to study aerosol processes fron nano to global scale and their effects on climate and air quality. In addition a new Pan-European aerosol emissions inventory was developed and evaluated, a new cluster spectrometer was built and tested in the field and several new aerosol parameterizations and computations modules for chemical transport and global climate models were developed and evaluated. These achievements and related studies have substantially improved our understanding and reduced the uncertainties of aerosol radiative forcing and air quality-climate interactions. The EUCAARI results can be utilized in European and global environmental policy to assess the aerosol impacts and the corresponding abatement strategies.
  •  
9.
  • Arandia-Gorostidi, Nestor, et al. (författare)
  • Efficient carbon and nitrogen transfer from marine diatom aggregates to colonizing bacterial groups
  • 2022
  • Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 12:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Bacterial degradation of sinking diatom aggregates is key for the availability of organic matter in the deep-ocean. Yet, little is known about the impact of aggregate colonization by different bacterial taxa on organic carbon and nutrient cycling within aggregates. Here, we tracked the carbon (C) and nitrogen (N) transfer from the diatom Leptocylindrus danicus to different environmental bacterial groups using a combination of C-13 and N-15 isotope incubation (incubated for 72 h), CARD-FISH and nanoSIMS single-cell analysis. Pseudoalteromonas bacterial group was the first colonizing diatom-aggregates, succeeded by the Alteromonas group. Within aggregates, diatom-attached bacteria were considerably more enriched in C-13 and N-15 than non-attached bacteria. Isotopic mass balance budget indicates that both groups showed comparable levels of diatom C in their biomass, accounting for 19 +/- 7% and 15 +/- 11%, respectively. In contrast to C, bacteria of the Alteromonas groups showed significantly higher levels of N derived from diatoms (77 +/- 28%) than Pseudoalteromonas (47 +/- 17%), suggesting a competitive advantage for Alteromonas in the N-limiting environments of the deep-sea. Our results imply that bacterial succession within diatom aggregates may largely impact taxa-specific C and N uptake, which may have important consequences for the quantity and quality of organic matter exported to the deep ocean.
  •  
10.
  • Moradi, Nasrollah, et al. (författare)
  • A Novel Measurement-Based Model for Calculating Diffusive Fluxes Across Substrate-Water Interfaces of Marine Aggregates, Sediments and Biofilms
  • 2021
  • Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 8
  • Tidskriftsartikel (refereegranskat)abstract
    • Our understanding of the small-scale processes that drive global biogeochemical cycles and the Earth’s climate is dependent on accurate estimations of interfacial diffusive fluxes to and from biologically-active substrates in aquatic environments. In this study, we present a novel model approach for accurate calculations of diffusive fluxes of dissolved gases, nutrients, and solutes from concentration profiles measured across the substrate-water interfaces using microsensors. The model offers a robust computational scheme for automatized determination of the interface position and enables precise calculations of the interfacial diffusive fluxes simultaneously. In contrast to other methods, the new approach is not restricted to any particular substrate geometry, does not require a priori determination of the interface position for the flux calculation, and, thus, reduces the uncertainties in calculated fluxes arising from partly subjective identification of the interface position. In addition, it is robust when applied to measured profiles containing scattered data points and insensitive to reasonable decreases of the spatial resolution of the data points. The latter feature allows for significantly reducing measurement time which is a crucial factor for in situ experiments.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-10 av 16
Typ av publikation
tidskriftsartikel (15)
bok (1)
Typ av innehåll
refereegranskat (15)
populärvet., debatt m.m. (1)
Författare/redaktör
Allentoft, Morten E. (4)
Sikora, Martin (4)
Ingason, Andrés (4)
Kristiansen, Kristia ... (4)
McColl, Hugh (4)
Rosengren, Anders (3)
visa fler...
Lynnerup, Niels (3)
Sjögren, Karl-Göran, ... (3)
Hickler, Thomas (3)
Björkman, Anne, 1981 (3)
Fischer, Anders, 195 ... (3)
Macleod, Ruairidh (3)
Stenderup, Jesper (3)
Refoyo-Martínez, Alb ... (3)
Barrie, William (3)
Pearson, Alice (3)
Demeter, Fabrice (3)
Henriksen, Rasmus A. (3)
Vimala, Tharsika (3)
Renaud, Gabriel (3)
Diaz, Sandra (2)
Cornelissen, J. Hans ... (2)
Forbes, Bruce C. (2)
Grogan, Paul (2)
Molau, Ulf, 1951 (2)
Oberbauer, Steven F. (2)
Zhao, Lei (2)
Ploug, Helle (2)
Luo, Yiqi (2)
Wang, Ying Ping (2)
Norby, Richard J. (2)
Alatalo, Juha M. (2)
Michelsen, Anders (2)
Little, Chelsea J. (2)
Poschlod, Peter (2)
Dainese, Matteo (2)
Grau, Oriol (2)
van Bodegom, Peter M ... (2)
Jørkov, Marie Louise ... (2)
Price, T. Douglas (2)
Fischer Mortensen, M ... (2)
Nielsen, Anne Birgit ... (2)
Ulfeldt Hede, Mikkel (2)
Sørensen, Lasse (2)
Nielsen, Poul Otto (2)
Rasmussen, Peter (2)
Jensen, Theis Zetner ... (2)
Sousa da Mota, Bárba ... (2)
Vaughn, Andrew (2)
Vinner, Lasse (2)
visa färre...
Lärosäte
Göteborgs universitet (8)
Lunds universitet (7)
Sveriges Lantbruksuniversitet (5)
Högskolan Kristianstad (1)
Umeå universitet (1)
Uppsala universitet (1)
visa fler...
Stockholms universitet (1)
Chalmers tekniska högskola (1)
Karlstads universitet (1)
visa färre...
Språk
Engelska (16)
Forskningsämne (UKÄ/SCB)
Humaniora (4)
Lantbruksvetenskap (2)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy