| 1. |
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| 2. |
- Botvinik-Nezer, Rotem, et al.
(author)
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Variability in the analysis of a single neuroimaging dataset by many teams
- 2020
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 582, s. 84-88
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Journal article (peer-reviewed)abstract
- Data analysis workflows in many scientific domains have become increasingly complex and flexible. Here we assess the effect of this flexibility on the results of functional magnetic resonance imaging by asking 70 independent teams to analyse the same dataset, testing the same 9 ex-ante hypotheses(1). The flexibility of analytical approaches is exemplified by the fact that no two teams chose identical workflows to analyse the data. This flexibility resulted in sizeable variation in the results of hypothesis tests, even for teams whose statistical maps were highly correlated at intermediate stages of the analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Notably, a meta-analytical approach that aggregated information across teams yielded a significant consensus in activated regions. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset(2-5). Our findings show that analytical flexibility can have substantial effects on scientific conclusions, and identify factors that may be related to variability in the analysis of functional magnetic resonance imaging. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for performing and reporting multiple analyses of the same data. Potential approaches that could be used to mitigate issues related to analytical variability are discussed. The results obtained by seventy different teams analysing the same functional magnetic resonance imaging dataset show substantial variation, highlighting the influence of analytical choices and the importance of sharing workflows publicly and performing multiple analyses.
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| 3. |
- Reed, Mark S., et al.
(author)
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The future of the uplands
- 2009
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In: Land use policy. - : Elsevier Limited. - 0264-8377 .- 1873-5754. ; 26:Supplement 1
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Journal article (peer-reviewed)abstract
- Upland areas provide UK society with many important functions, goods and services, but have experienced a number of disturbing trends and face an uncertain future. This paper outlines historic, current and future drivers of environmental, economic, socio-cultural and policy change in UK uplands, and assesses how these have affected or are likely to affect ways in which land is used and the provision of ecosystem services. Information is synthesised into scenarios summarising a range of possible futures anticipated for UK uplands to 2060 and beyond. Finally, innovations in science, technology, governance and policy are evaluated that could enable uplands to continue providing key ecosystem services under a range of scenarios. The paper concludes that many upland areas will need to be prepared for significant reductions in grazing and prescribed burning. Conversely, other areas could experience agricultural intensification, for example significant increases in grazing or an expansion of arable or bioenergy crops into upland valleys, due to anticipated increases in global demand for food and energy. These scenarios will take place in the context of climate change. Many may take place together and may interact with each other, with complex and unpredictable implications for the upland environment, economy and society. In this context, a number of advances are needed in science, technology and policy to maintain viable uplandcommunities and the future provision of ecosystem services. These may include funding for ecological and hydrological restoration via carbon offsetting or other means. It may also involve advances in ecosystem service modelling, mapping and valuation, which through stakeholder participation could facilitate more integrated rural planning. New forms of environmental governance need to be explored that can empower those interested in developing upland economies to maintain thriving upland communities, while managing the ecosystem services they provide as efficiently as possible.
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| 4. |
- Tinyanont, S., et al.
(author)
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Keck Infrared Transient Survey. I. Survey Description and Data Release 1
- 2024
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In: Publications of the Astronomical Society of the Pacific. - 0004-6280 .- 1538-3873. ; 136:1
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Journal article (peer-reviewed)abstract
- We present the Keck Infrared Transient Survey, a NASA Key Strategic Mission Support program to obtain near-infrared (NIR) spectra of astrophysical transients of all types, and its first data release, consisting of 105 NIR spectra of 50 transients. Such a data set is essential as we enter a new era of IR astronomy with the James Webb Space Telescope (JWST) and the upcoming Nancy Grace Roman Space Telescope (Roman). NIR spectral templates will be essential to search JWST images for stellar explosions of the first stars and to plan an effective Roman SN Ia cosmology survey, both key science objectives for mission success. Between 2022 February and 2023 July, we systematically obtained 274 NIR spectra of 146 astronomical transients, representing a significant increase in the number of available NIR spectra in the literature. Here, we describe the first release of data from the 2022A semester. We systematically observed three samples: a flux-limited sample that includes all transients <17 mag in a red optical band (usually ZTF r or ATLAS o bands); a volume-limited sample including all transients within redshift z < 0.01 (D ≈ 50 Mpc); and an SN Ia sample targeting objects at phases and light-curve parameters that had scant existing NIR data in the literature. The flux-limited sample is 39% complete (60% excluding SNe Ia), while the volume-limited sample is 54% complete and is 79% complete to z = 0.005. Transient classes observed include common Type Ia and core-collapse supernovae, tidal disruption events, luminous red novae, and the newly categorized hydrogen-free/helium-poor interacting Type Icn supernovae. We describe our observing procedures and data reduction using PypeIt, which requires minimal human interaction to ensure reproducibility.
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| 5. |
- Maasri, Alain, et al.
(author)
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A global agenda for advancing freshwater biodiversity research
- 2022
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In: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 25:2, s. 255-263
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Journal article (peer-reviewed)abstract
- Global freshwater biodiversity is declining dramatically, and meeting the challenges of this crisis requires bold goals and the mobilisation of substantial resources. While the reasons are varied, investments in both research and conservation of freshwater biodiversity lag far behind those in the terrestrial and marine realms. Inspired by a global consultation, we identify 15 pressing priority needs, grouped into five research areas, in an effort to support informed stewardship of freshwater biodiversity. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated actions towards its sustainable management and conservation.
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| 6. |
- Brett, Michael T., et al.
(author)
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How important are terrestrial organic carbon inputs for secondary production in freshwater ecosystems?
- 2017
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In: Freshwater Biology. - : WILEY. - 0046-5070 .- 1365-2427. ; 62:5, s. 833-853
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Research review (peer-reviewed)abstract
- 1. Many freshwater systems receive substantial inputs of terrestrial organic matter. Terrestrially derived dissolved organic carbon (t-DOC) inputs can modify light availability, the spatial distribution of primary production, heat, and oxygen in aquatic systems, as well as inorganic nutrient bioavailability. It is also well-established that some terrestrial inputs (such as invertebrates and fruits) provide high-quality food resources for consumers in some systems. 2. In small to moderate-sized streams, leaf litter inputs average approximately three times greater than the autochthonous production. Conversely, in oligo/mesotrophic lakes algal production is typically five times greater than the available flux of allochthonous basal resources. 3. Terrestrial particulate organic carbon (t-POC) inputs to lakes and rivers are comprised of 80%-90% biochemically recalcitrant lignocellulose, which is highly resistant to enzymatic breakdown by animal consumers. Further, t-POC and heterotrophic bacteria lack essential biochemical compounds that are critical for rapid growth and reproduction in aquatic invertebrates and fishes. Several studies have directly shown that these resources have very low food quality for herbivorous zooplankton and benthic invertebrates 4. Much of the nitrogen assimilated by stream consumers is probably of algal origin, even in systems where there appears to be a significant terrestrial carbon contribution. Amino acid stable isotope analyses for large river food webs indicate that most upper trophic level essential amino acids are derived from algae. Similarly, profiles of essential fatty acids in consumers show a strong dependence on the algal food resources. 5. Primary production to respiration ratios are not a meaningful index to assess consumer allochthony because respiration represents an oxidised carbon flux that cannot be utilised by animal consumers. Rather, the relative importance of allochthonous subsidies for upper trophic level production should be addressed by considering the rates at which terrestrial and autochthonous resources are consumed and the growth efficiency supported by this food. 6. Ultimately, the biochemical composition of a particular basal resource, and not just its quantity or origin, determines how readily this material is incorporated into upper trophic level consumers. Because of its highly favourable biochemical composition and greater availability, we conclude that microalgal production supports most animal production in freshwater ecosystems.
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| 7. |
- Coutu, Ashley N., et al.
(author)
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Mapping the Elephants of the 19th Century East African Ivory Trade with a Multi-Isotope Approach
- 2016
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:10
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Journal article (peer-reviewed)abstract
- East African elephants have been hunted for their ivory for millennia but the nineteenth century witnessed strongly escalating demand from Europe and North America. It has been suggested that one consequence was that by the 1880s elephant herds along the coast had become scarce, and to meet demand, trade caravans trekked farther into interior regions of East Africa, extending the extraction frontier. The steady decimation of elephant populations coupled with the extension of trade networks have also been claimed to have triggered significant ecological and socio-economic changes that left lasting legacies across the region. To explore the feasibility of using an isotopic approach to uncover a 'moving frontier' of elephant extraction, we constructed a baseline isotope data set (delta C-13, delta N-15, delta O-18 and Sr-87/Sr-86) for historic East African elephants known to have come from three distinct regions (coastal, Rift Valley, and inland Lakes). Using the isotope results with other climate data and geographical mapping tools, it was possible to characterise elephants from different habitats across the region. This baseline data set was then used to provenance elephant ivory of unknown geographical provenance that was exported from East Africa during the late nineteenth and early twentieth centuries to determine its likely origin. This produced a better understanding of historic elephant geography in the region, and the data have the potential to be used to provenance older archaeological ivories, and to inform contemporary elephant conservation strategies.
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| 8. |
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| 9. |
- Bowes, Rachel E., et al.
(author)
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Consequences of employing amino acid vs. bulk-tissue, stable isotope analysis : a laboratory trophic position experiment
- 2015
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In: Ecosphere. - : John Wiley & Sons. - 2150-8925 .- 2150-8925. ; 6:1, s. 1-12
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Journal article (peer-reviewed)abstract
- An important metric of environmental health is food web structure because it reflects species richness, natural history diversity, and resource availability. While bulk-tissue stable isotope analysis has proven valuable for food web studies, field conditions may severely restrict its use and data can be quite variable. Amino acid stable isotope analysis potentially reduces this variability, in part by eliminating the need for signatures near the trophic base because a single top consumer contains both the primary producer signature (constant phenylalanine signature) and information reflecting number of trophic transfers (a progressively increasing d15N signature of glutamic acid). To evaluate the ecological sensitivity and cost/benefits of the techniques, we conducted a laboratory food chain experiment with four trophic levels. Water fleas (Daphnia magna) were cultured on a diet of powdered algae and then fed daily to guppies (Poecilia reticulata) for three months. These invertivorous fishes were then consumed by piscivororus bluegill sunfishes (Lepomis macrochirus) for a subsequent three months. All members of the food web were analyzed for 15N values and degree of fractionation using both bulk-tissue and amino acid stable isotope techniques. Our experiment demonstrated that the amino acid technique more accurately identified the true trophic position (TP) and food chain length (FCL ¼ maximum TP) with significantly less variability around mean values for each consumer trophic level. Moreover, use of amino acids requires significantly fewer replicates to identify TP. We discuss here the relative advantages and disadvantages of both approaches for determining TP and FCL and recommend that investigators switch as soon as possible to the amino acid isotope technique for determining FCL.
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| 10. |
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| 11. |
- Kelly, Patrick L., et al.
(author)
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Constraints on the Hubble constant from supernova Refsdal's reappearance
- 2023
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In: Science. - 0036-8075 .- 1095-9203. ; 380:6649
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Journal article (peer-reviewed)abstract
- The gravitationally lensed supernova Refsdal appeared in multiple images produced through gravitational lensing by a massive foreground galaxy cluster. After the supernova appeared in 2014, lens models of the galaxy cluster predicted that an additional image of the supernova would appear in 2015, which was subsequently observed. We use the time delays between the images to perform a blinded measurement of the expansion rate of the Universe, quantified by the Hubble constant (H0). Using eight cluster lens models, we infer kilometers per second per megaparsec. Using the two models most consistent with the observations, we find kilometers per second per megaparsec. The observations are best reproduced by models that assign dark-matter halos to individual galaxies and the overall cluster.
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| 12. |
- Kleijn, David, et al.
(author)
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Delivery of crop pollination services is an insufficient argument for wild pollinator conservation.
- 2015
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 6
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Journal article (peer-reviewed)abstract
- There is compelling evidence that more diverse ecosystems deliver greater benefits to people, and these ecosystem services have become a key argument for biodiversity conservation. However, it is unclear how much biodiversity is needed to deliver ecosystem services in a cost-effective way. Here we show that, while the contribution of wild bees to crop production is significant, service delivery is restricted to a limited subset of all known bee species. Across crops, years and biogeographical regions, crop-visiting wild bee communities are dominated by a small number of common species, and threatened species are rarely observed on crops. Dominant crop pollinators persist under agricultural expansion and many are easily enhanced by simple conservation measures, suggesting that cost-effective management strategies to promote crop pollination should target a different set of species than management strategies to promote threatened bees. Conserving the biological diversity of bees therefore requires more than just ecosystem-service-based arguments.
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| 13. |
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| 14. |
- Shipton, Ceri, et al.
(author)
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78,000-year-old record of Middle and Later stone age innovation in an East African tropical forest
- 2018
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9:1
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Journal article (peer-reviewed)abstract
- The Middle to Later Stone Age transition in Africa has been debated as a significant shift in human technological, cultural, and cognitive evolution. However, the majority of research on this transition is currently focused on southern Africa due to a lack of long-term, stratified sites across much of the African continent. Here, we report a 78,000-year-long archeological record from Panga ya Saidi, a cave in the humid coastal forest of Kenya. Following a shift in toolkits ~67,000 years ago, novel symbolic and technological behaviors assemble in a non-unilinear manner. Against a backdrop of a persistent tropical forest-grassland ecotone, localized innovations better characterize the Late Pleistocene of this part of East Africa than alternative emphases on dramatic revolutions or migrations.
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| 15. |
- Ward, Sam M., et al.
(author)
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Relative Intrinsic Scatter in Hierarchical Type Ia Supernova Sibling Analyses : Application to SNe 2021hpr, 1997bq, and 2008fv in NGC 3147
- 2023
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In: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 956:2
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Journal article (peer-reviewed)abstract
- We present Young Supernova Experiment grizy photometry of SN 2021hpr, the third Type Ia supernova sibling to explode in the Cepheid calibrator galaxy, NGC 3147. Siblings are useful for improving SN-host distance estimates and investigating their contributions toward the SN Ia intrinsic scatter (post-standardization residual scatter in distance estimates). We thus develop a principled Bayesian framework for analyzing SN Ia siblings. At its core is the cosmology-independent relative intrinsic scatter parameter, σRel: the dispersion of siblings distance estimates relative to one another within a galaxy. It quantifies the contribution toward the total intrinsic scatter, σ0, from within-galaxy variations about the siblings' common properties. It also affects the combined distance uncertainty. We present analytic formulae for computing a σRel posterior from individual siblings distances (estimated using any SN model). Applying a newly trained BAYESN model, we fit the light curves of each sibling in NGC 3147 individually, to yield consistent distance estimates. However, the wide σRel posterior means σRel ≈ σ0 is not ruled out. We thus combine the distances by marginalizing over σRel with an informative prior: σRel ∼ U(0, σ0). Simultaneously fitting the trio's light curves improves constraints on distance and each sibling's individual dust parameters, compared to individual fits. Higher correlation also tightens dust parameter constraints. Therefore, σRel marginalization yields robust estimates of siblings distances for cosmology, as well as dust parameters for sibling–host correlation studies. Incorporating NGC 3147's Cepheid distance yields H0 = 78.4 ± 6.5 km s−1 Mpc−1. Our work motivates analyses of homogeneous siblings samples, to constrain σRel and its SN-model dependence.
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| 16. |
- Ölvander, Johan, et al.
(author)
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Preface
- 2018
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In: Proceedings of NordDesign: Design in the Era of Digitalization, NordDesign 2018.
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Conference paper (other academic/artistic)
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