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  • 1. Abramowski, A.
    et al.
    Aharonian, F.
    Benkhali, F. Ait
    Akhperjanian, A. G.
    Anguener, E. O.
    Backes, M.
    Balzer, A.
    Becherini, Y.
    Tjus, J. Becker
    Berge, D.
    Bernhard, S.
    Bernloehr, K.
    Birsin, E.
    Blackwell, R.
    Boettcher, M.
    Boisson, C.
    Bolmont, J.
    Bordas, P.
    Bregeon, J.
    Brun, F.
    Brun, P.
    Bryan, M.
    Bulik, T.
    Carr, J.
    Casanova, S.
    Chakraborty, N.
    Chalme-Calvet, R.
    Chaves, R. C. G.
    Chen, A.
    Chretien, M.
    Colafrancesco, S.
    Cologna, G.
    Conrad, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Fysikum. Stockholms universitet, Naturvetenskapliga fakulteten, Oskar Klein-centrum för kosmopartikelfysik (OKC).
    Couturier, C.
    Cui, Y.
    Davids, I. D.
    Degrange, B.
    Deil, C.
    deWilt, P.
    Djannati-Ata, A.
    Domainko, W.
    Donath, A.
    Drury, L. O'C.
    Dubus, G.
    Dutson, K.
    Dyks, J.
    Dyrda, M.
    Edwards, T.
    Egberts, K.
    Eger, P.
    Ernenwein, J-P.
    Espigat, P.
    Farnier, Christian
    Stockholms universitet, Naturvetenskapliga fakulteten, Fysikum. Stockholms universitet, Naturvetenskapliga fakulteten, Oskar Klein-centrum för kosmopartikelfysik (OKC).
    Fegan, S.
    Feinstein, F.
    Fernandes, M. V.
    Fernandez, D.
    Fiasson, A.
    Fontaine, G.
    Foerster, A.
    Fuessling, M.
    Gabici, S.
    Gajdus, M.
    Gallant, Y. A.
    Garrigoux, T.
    Giavitto, G.
    Giebels, B.
    Glicenstein, J. F.
    Gottschall, D.
    Goyal, A.
    Grondin, M-H.
    Grudzinska, M.
    Hadasch, D.
    Haeffner, S.
    Hahn, J.
    Hawkes, J.
    Heinzelmann, G.
    Henri, G.
    Hermann, G.
    Hervet, O.
    Hillert, A.
    Hinton, J. A.
    Hofmann, W.
    Hofverberg, P.
    Hoischen, C.
    Holler, M.
    Horns, D.
    Ivascenko, A.
    Jacholkowska, A.
    Jamrozy, M.
    Janiak, M.
    Jankowsky, F.
    Jung-Richardt, I.
    Kastendieck, M. A.
    Katarzynski, K.
    Katz, U.
    Kerszberg, D.
    Khelifi, B.
    Kieffer, M.
    Klepser, S.
    Klochkov, D.
    Kluzniak, W.
    Kolitzus, D.
    Komin, Nu.
    Kosack, K.
    Krakau, S.
    Krayzel, F.
    Krueger, P. P.
    Laffon, H.
    Lamanna, G.
    Lau, J.
    Lefaucheur, J.
    Lefranc, V.
    Lemiere, A.
    Lemoine-Goumard, M.
    Lenain, J-P.
    Lohse, T.
    Lopatin, A.
    Lu, C-C.
    Lui, R.
    Marandon, V.
    Marcowith, A.
    Mariaud, C.
    Marx, R.
    Maurin, G.
    Maxted, N.
    Mayer, M.
    Meintjes, P. J.
    Menzler, U.
    Meyer, Manuel
    Stockholms universitet, Naturvetenskapliga fakulteten, Fysikum. Stockholms universitet, Naturvetenskapliga fakulteten, Oskar Klein-centrum för kosmopartikelfysik (OKC).
    Mitchell, A. M. W.
    Moderski, R.
    Mohamed, M.
    Morå, Knut
    Stockholms universitet, Naturvetenskapliga fakulteten, Fysikum. Stockholms universitet, Naturvetenskapliga fakulteten, Oskar Klein-centrum för kosmopartikelfysik (OKC).
    Moulin, E.
    Murach, T.
    de Naurois, M.
    Niemiec, J.
    Oakes, L.
    Odaka, H.
    Oettl, S.
    Ohm, S.
    Opitz, B.
    Ostrowski, M.
    Oya, I.
    Panter, M.
    Parsons, R. D.
    Arribas, M. Paz
    Pekeur, N. W.
    Pelletier, G.
    Petrucci, P-O.
    Peyaud, B.
    Pita, S.
    Poon, H.
    Prokoph, H.
    Puehlhofer, G.
    Punch, M.
    Quirrenbach, A.
    Raab, S.
    Reichardt, I.
    Reimer, A.
    Reimer, O.
    Renaud, M.
    de los Reyes, R.
    Rieger, F.
    Romoli, C.
    Rosier-Lees, S.
    Rowell, G.
    Rudak, B.
    Rulten, C. B.
    Sahakian, V.
    Salek, D.
    Sanchez, D. A.
    Santangelo, A.
    Sasaki, M.
    Schlickeiser, R.
    Schuessler, F.
    Schulz, A.
    Schwanke, U.
    Schwemmer, S.
    Seyffert, A. S.
    Simoni, R.
    Sol, H.
    Spanier, F.
    Spengler, Gerrit
    Stockholms universitet, Naturvetenskapliga fakulteten, Fysikum. Stockholms universitet, Naturvetenskapliga fakulteten, Oskar Klein-centrum för kosmopartikelfysik (OKC).
    Spies, F.
    Stawarz, L.
    Steenkamp, R.
    Stegmann, C.
    Stinzing, F.
    Stycz, K.
    Sushch, I.
    Tavernet, J-P.
    Tavernier, T.
    Taylor, A. M.
    Terrier, R.
    Tluczykont, M.
    Trichard, C.
    Tuffs, R.
    Valerius, K.
    van der Walt, J.
    van Eldik, C.
    van Soelen, B.
    Vasileiadis, G.
    Veh, J.
    Venter, C.
    Viana, A.
    Vincent, P.
    Vink, J.
    Voisin, F.
    Voelk, H. J.
    Vuillaume, T.
    Wagner, S. J.
    Wagner, P.
    Wagner, Roger M.
    Stockholms universitet, Naturvetenskapliga fakulteten, Fysikum. Stockholms universitet, Naturvetenskapliga fakulteten, Oskar Klein-centrum för kosmopartikelfysik (OKC).
    Weidinger, M.
    Weitzel, Q.
    White, R.
    Wierzcholska, A.
    Willmann, P.
    Woernlein, A.
    Wouters, D.
    Yang, R.
    Zabalza, V.
    Zaborov, D.
    Zacharias, M.
    Zdziarski, A. A.
    Zech, A.
    Zefi, F.
    Zywucka, N.
    Acceleration of petaelectronvolt protons in the Galactic Centre2016Inngår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 531, nr 7595, s. 476-+Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Galactic cosmic rays reach energies of at least a few petaelectronvolts(1) (of the order of 1015 electronvolts). This implies that our Galaxy contains petaelectronvolt accelerators ('PeVatrons'), but all proposed models of Galactic cosmic-ray accelerators encounter difficulties at exactly these energies(2). Dozens of Galactic accelerators capable of accelerating particles to energies of tens of teraelectronvolts (of the order of 10(13) electronvolts) were inferred from recent gamma-ray observations(3). However, none of the currently known accelerators-not even the handful of shell-type supernova remnants commonly believed to supply most Galactic cosmic rays-has shown the characteristic tracers of petaelectronvolt particles, namely, power-law spectra of.-rays extending without a cut-off or a spectral break to tens of teraelectronvolts(4). Here we report deep.-ray observations with arcminute angular resolution of the region surrounding the Galactic Centre, which show the expected tracer of the presence of petaelectronvolt protons within the central 10 parsecs of the Galaxy. We propose that the supermassive black hole Sagittarius A* is linked to this PeVatron. Sagittarius A* went through active phases in the past, as demonstrated by X-ray outbursts(5) and an outflow from the Galactic Centre(6). Although its current rate of particle acceleration is not sufficient to provide a substantial contribution to Galactic cosmic rays, Sagittarius A* could have plausibly been more active over the last 10(6)-10(7) years, and therefore should be considered as a viable alternative to supernova remnants as a source of petaelectronvolt Galactic cosmic rays.

  • 2. Agarwal, Sahil
    et al.
    Wettlaufer, John S.
    Stockholms universitet, Nordiska institutet för teoretisk fysik (Nordita). Yale University, USA; University of Oxford, UK.
    Fluctuations in Arctic sea-ice extent: comparing observations and climate models2018Inngår i: Philosophical Transactions. Series A: Mathematical, physical, and engineering science, ISSN 1364-503X, E-ISSN 1471-2962, Vol. 376, nr 2129, artikkel-id 20170332Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The fluctuation statistics of the observed sea-ice extent during the satellite era are compared with model output from CMIP5 models using a multifractal time series method. The two robust features of the observations are that on annual to biannual time scales the ice extent exhibits white noise structure, and there is a decadal scale trend associated with the decay of the ice cover. It is shown that (i) there is a large inter-model variability in the time scales extracted from the models, (ii) none of the models exhibits the decadal time scales found in the satellite observations, (iii) five of the 21 models examined exhibit the observed white noise structure, and (iv) the multi-model ensemble mean exhibits neither the observed white noise structure nor the observed decadal trend. It is proposed that the observed fluctuation statistics produced by this method serve as an appropriate test bed for modelling studies. This article is part of the theme issue 'Modelling of sea-ice phenomena'.

  • 3.
    Aili, Hans
    et al.
    Stockholms universitet, Humanistiska fakulteten, Romanska och klassiska institutionen.
    Pietsch, Theodore W
    University of Washington, Seattle.
    Jacob Theodor Klein's Critique of Peter Artedi's Ichthyologia (1738)2014Inngår i: Svenska Linnésällskapets årsskrift, ISSN 0375-2038, s. 39-84Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An anonymous critique of Peter Artedi’s (1705‒1735) Ichthyologia sive opera omnia de piscibus, the latter edited and published posthumously by Carolus Linnaeus (1707‒ 1778) in 1738, is shown to have been written by the Prussian jurist and naturalist Jacob Theodor Klein (1685‒1759), and sent to Hans Sloane (1660−1753) in London for his approval. The critique is transcribed and translated, and its contents assessed in light of Artedi’s contribution to Linnaean systematics. While in some ways highly critical of Artedi, Klein must have been well aware that by criticizing Artedi he was, by association, criticizing Linnaeus as well. Linnaeus’s editorial contributions to the Ichthyologia as well as his on-going antagonistic relationship with Klein are also discussed.

  • 4. Anderson, Bruce T.
    et al.
    Hassanzadeh, Pedram
    Caballero, Rodrigo
    Stockholms universitet, Naturvetenskapliga fakulteten, Meteorologiska institutionen (MISU).
    Persistent anomalies of the extratropical Northern Hemisphere wintertime circulation as an initiator of El Nino/Southern Oscillation events2017Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, artikkel-id 10145Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Climates across both hemispheres are strongly influenced by tropical Pacific variability associated with the El Nino/Southern Oscillation (ENSO). Conversely, extratropical variability also can affect the tropics. In particular, seasonal-mean alterations of near-surface winds associated with the North Pacific Oscillation (NPO) serve as a significant extratropical forcing agent of ENSO. However, it is still unclear what dynamical processes give rise to year-to-year shifts in these long-lived NPO anomalies. Here we show that intraseasonal variability in boreal winter pressure patterns over the Central North Pacific (CNP) imparts a significant signature upon the seasonal-mean circulations characteristic of the NPO. Further we show that the seasonal-mean signature results in part from year-to-year variations in persistent, quasi-stationary low-pressure intrusions into the subtropics of the CNP, accompanied by the establishment of persistent, quasi-stationary high-pressure anomalies over high latitudes of the CNP. Overall, we find that the frequency of these persistent extratropical anomalies (PEAs) during a given winter serves as a key modulator of intraseasonal variability in extratropical North Pacific circulations and, through their influence on the seasonal-mean circulations in and around the southern lobe of the NPO, the state of the equatorial Pacific 9-12 months later.

  • 5.
    Andersson, Ole
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Fysikum.
    Bengtsson, Ingemar
    Stockholms universitet, Naturvetenskapliga fakulteten, Fysikum.
    Ericsson, Marie
    Sjöqvist, Erik
    Geometric phases for mixed states of the Kitaev chain2016Inngår i: Philosophical Transactions. Series A: Mathematical, physical, and engineering science, ISSN 1364-503X, E-ISSN 1471-2962, Vol. 374, nr 2068, artikkel-id 20150231Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Berry phase has found applications in building topological order parameters for certain condensed matter systems. The question whether some geometric phase for mixed states can serve the same purpose has been raised, and proposals are on the table. We analyse the intricate behaviour of Uhlmann's geometric phase in the Kitaev chain at finite temperature, and then argue that it captures quite different physics from that intended. We also analyse the behaviour of a geometric phase introduced in the context of interferometry. For the Kitaev chain, this phase closely mirrors that of the Berry phase, and we argue that it merits further investigation.

  • 6.
    Andersson, Sara
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholm Resilience Centre.
    Mapping supply and demand of ecosystem services in the Helge Å catchment area, Sweden2016Independent thesis Advanced level (degree of Master (Two Years)), 40 poäng / 60 hpOppgave
    Abstract [en]

    Research on ecosystem services has accelerated the last few years, but there is a knowledge gap on how to integrate the concept into management in a way that is mindful of the complex, dynamic and non-linear dimensions of ecosystem services. Ecosystem services are often approached from a supply side, and more often than not services are approached individually without attempt to capture the trade-offs and synergies between services. The overall aim of this master’s thesis is to contribute to the operationalization of the ecosystem services concept, within a social-ecological systems framework. This is done through a case study of the Helge Å catchment in Southern Sweden, in which I use publically available data to map the supply and demand of a selection of locally relevant provisioning, regulating, and, to some extent, cultural ecosystem services. The thesis analyses some of the challenges of, as well as opportunities for, making tangible sense of this complex social-ecological concept in a way that can inform decision making on ecosystem services for sustainable development. The results show that mapping both supply and demand adds important dimensions to ecosystem service assessment that has value within management contexts. Especially important are the added social dimensions of ecosystem service provision, and the incorporation of societal demand as a factor in mapping. There are some obvious challenges still associated with this type of mapping, foremost associated with mapping of cultural ecosystem services and data availability, which have yet to be resolved through continued research efforts.

  • 7. Arcavi, Iair
    et al.
    Howell, D. Andrew
    Kasen, Daniel
    Bildsten, Lars
    Hosseinzadeh, Griffin
    McCully, Curtis
    Wong, Zheng Chuen
    Katz, Sarah Rebekah
    Gal-Yam, Avishay
    Sollerman, Jesper
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för astronomi. Stockholms universitet, Naturvetenskapliga fakulteten, Oskar Klein-centrum för kosmopartikelfysik (OKC).
    Taddia, Francesco
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för astronomi. Stockholms universitet, Naturvetenskapliga fakulteten, Oskar Klein-centrum för kosmopartikelfysik (OKC).
    Leloudas, Giorgos
    Fremling, Christoffer
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för astronomi. Stockholms universitet, Naturvetenskapliga fakulteten, Oskar Klein-centrum för kosmopartikelfysik (OKC).
    Nugent, Peter E.
    Horesh, Assaf
    Mooley, Kunal
    Rumsey, Clare
    Cenko, S. B. Radley
    Graham, Melissa L.
    Perley, Daniel A.
    Nakar, Ehud
    Shaviv, Nir J.
    Bromberg, Omer
    Shen, Ken J.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för astronomi. Stockholms universitet, Naturvetenskapliga fakulteten, Oskar Klein-centrum för kosmopartikelfysik (OKC).
    Ofek, Eran O.
    Cao, Yi
    Wang, Xiaofeng
    Huang, Fang
    Rui, Liming
    Zhang, Tianmeng
    Li, Wenxiong
    Li, Zhitong
    Zhang, Jujia
    Valenti, Stefano
    Guevel, David
    Shappee, Benjamin
    Kochanek, Christopher S.
    Holoien, Thomas W. -S.
    Filippenko, Alexei V.
    Fender, Rob
    Nyholm, Anders
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för astronomi. Stockholms universitet, Naturvetenskapliga fakulteten, Oskar Klein-centrum för kosmopartikelfysik (OKC).
    Yaron, Ofer
    Kasliwal, Mansi M. .
    Sullivan, Mark
    Lagorodnova, Nadja B.
    Walters, Richard S.
    Lunnan, Ragnhild
    Khazov, Danny
    Andreoni, Igor
    Laher, Russ R.
    Konidaris, Nick
    Wozniak, Przemek
    Bue, Brian
    Energetic eruptions leading to a peculiar hydrogen-rich explosion of a massive star2017Inngår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 551, nr 7679, s. 210-213Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Every supernova so far observed has been considered to be the terminal explosion of a star. Moreover, all supernovae with absorption lines in their spectra show those lines decreasing in velocity over time, as the ejecta expand and thin, revealing slower-moving material that was previously hidden. In addition, every supernova that exhibits the absorption lines of hydrogen has one main light-curve peak, or a plateau in luminosity, lasting approximately 100 days before declining(1). Here we report observations of iPTF14hls, an event that has spectra identical to a hydrogen-rich core-collapse supernova, but characteristics that differ extensively from those of known supernovae. The light curve has at least five peaks and remains bright for more than 600 days; the absorption lines show little to no decrease in velocity; and the radius of the line-forming region is more than an order of magnitude bigger than the radius of the photosphere derived from the continuum emission. These characteristics are consistent with a shell of several tens of solar masses ejected by the progenitor star at supernova-level energies a few hundred days before a terminal explosion. Another possible eruption was recorded at the same position in 1954. Multiple energetic pre-supernova eruptions are expected to occur in stars of 95 to 130 solar masses, which experience the pulsational pair instability(2-5). That model, however, does not account for the continued presence of hydrogen, or the energetics observed here. Another mechanism for the violent ejection of mass in massive stars may be required.

  • 8. Artiglia, Luca
    et al.
    Edebeli, Jacinta
    Orlando, Fabrizio
    Chen, Shuzhen
    Lee, Ming-Tao
    Stockholms universitet, Naturvetenskapliga fakulteten, Fysikum. Paul Scherrer Institut, Switzerland.
    Arroyo, Pablo Corral
    Gilgen, Anina
    Bartels-Rausch, Thorsten
    Kleibert, Armin
    Vazdar, Mario
    Carignano, Marcelo Andres
    Francisco, Joseph S.
    Shepson, Paul B.
    Gladich, Ivan
    Ammann, Markus
    A surface-stabilized ozonide triggers bromide oxidation at the aqueous solution-vapour interface2017Inngår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 8, artikkel-id 700Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Oxidation of bromide in aqueous environments initiates the formation of molecular halogen compounds, which is important for the global tropospheric ozone budget. In the aqueous bulk, oxidation of bromide by ozone involves a [Br center dot OOO-] complex as intermediate. Here we report liquid jet X-ray photoelectron spectroscopy measurements that provide direct experimental evidence for the ozonide and establish its propensity for the solution-vapour interface. Theoretical calculations support these findings, showing that water stabilizes the ozonide and lowers the energy of the transition state at neutral pH. Kinetic experiments confirm the dominance of the heterogeneous oxidation route established by this precursor at low, atmospherically relevant ozone concentrations. Taken together, our results provide a strong case of different reaction kinetics and mechanisms of reactions occurring at the aqueous phase-vapour interface compared with the bulk aqueous phase.

  • 9. Baeza-Delgado, Carlos
    et al.
    von Heijne, Gunnar
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Marti-Renom, Marc A.
    Mingarro, Ismael
    Biological insertion of computationally designed short transmembrane segments2016Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, artikkel-id 23397Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The great majority of helical membrane proteins are inserted co-translationally into the ER membrane through a continuous ribosome-translocon channel. The efficiency of membrane insertion depends on transmembrane (TM) helix amino acid composition, the helix length and the position of the amino acids within the helix. In this work, we conducted a computational analysis of the composition and location of amino acids in transmembrane helices found in membrane proteins of known structure to obtain an extensive set of designed polypeptide segments with naturally occurring amino acid distributions. Then, using an in vitro translation system in the presence of biological membranes, we experimentally validated our predictions by analyzing its membrane integration capacity. Coupled with known strategies to control membrane protein topology, these findings may pave the way to de novo membrane protein design.

  • 10.
    Balk, Lennart
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Hägerroth, Per-Åke
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Gustavsson, Hanna
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Sigg, Lisa
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Åkerman, Gun
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Ruiz Munoz, Yolanda
    Honeyfield, Dale C.
    Tjärnlund, Ulla
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Oliveira, Kenneth
    Ström, Karin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    McCormick, Stephen D.
    Karlsson, Simon
    Ström, Marika
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. Karolinska Institutet, Sweden.
    van Manen, Mathijs
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi. Utrecht University, Germany.
    Berg, Anna-Lena
    Halldorsson, Halldor P.
    Strömquist, Jennie
    Collier, Tracy K.
    Börjeson, Hans
    Mörner, Torsten
    Hansson, Tomas
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Widespread episodic thiamine deficiency in Northern Hemisphere wildlife2016Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, artikkel-id 38821Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Many wildlife populations are declining at rates higher than can be explained by known threats to biodiversity. Recently, thiamine (vitamin B-1) deficiency has emerged as a possible contributing cause. Here, thiamine status was systematically investigated in three animal classes: bivalves, ray-finned fishes, and birds. Thiamine diphosphate is required as a cofactor in at least five life-sustaining enzymes that are required for basic cellular metabolism. Analysis of different phosphorylated forms of thiamine, as well as of activities and amount of holoenzyme and apoenzyme forms of thiaminedependent enzymes, revealed episodically occurring thiamine deficiency in all three animal classes. These biochemical effects were also linked to secondary effects on growth, condition, liver size, blood chemistry and composition, histopathology, swimming behaviour and endurance, parasite infestation, and reproduction. It is unlikely that the thiamine deficiency is caused by impaired phosphorylation within the cells. Rather, the results point towards insufficient amounts of thiamine in the food. By investigating a large geographic area, by extending the focus from lethal to sublethal thiamine deficiency, and by linking biochemical alterations to secondary effects, we demonstrate that the problem of thiamine deficiency is considerably more widespread and severe than previously reported.

  • 11. Barnes, Michele L.
    et al.
    Bodin, Örjan
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholm Resilience Centre.
    McClanahan, Tim R.
    Kittinger, John N.
    Hoey, Andrew S.
    Gaoue, Orou G.
    Graham, Nicholas A. J.
    Social-ecological alignment and ecological conditions in coral reefs2019Inngår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 10, artikkel-id 2039Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Complex social-ecological interactions underpin many environmental problems. To help capture this complexity, we advance an interdisciplinary network modeling framework to identify important relationships between people and nature that can influence environmental conditions. Drawing on comprehensive social and ecological data from five coral reef fishing communities in Kenya; including interviews with 648 fishers, underwater visual census data of reef ecosystem condition, and time-series landings data; we show that positive ecological conditions are associated with 'social-ecological network closure' - i.e., fully linked and thus closed network structures between social actors and ecological resources. Our results suggest that when fishers facing common dilemmas form cooperative communication ties with direct resource competitors, they may achieve positive gains in reef fish biomass and functional richness. Our work provides key empirical insight to a growing body of research on social-ecological alignment, and helps to advance an integrative framework that can be applied empirically in different social-ecological contexts.

  • 12. Belton, Lydia E.
    et al.
    Cameron, Elissa Z.
    Dalerum, Fredrik
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen. University of Pretoria, South Africa; University of Oviedo, Spa.
    Spotted hyaena space use in relation to human infrastructure inside a protected area2016Inngår i: PeerJ, ISSN 2167-8359, E-ISSN 2167-8359, Vol. 4, artikkel-id e2596Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Increasing human population growth has led to elevated levels of human-carnivore conflict. However, some carnivore populations have adapted to urban environments and the resources they supply. Such associations may influence carnivore ecology, behaviour and life-history. Pockets of urbanisation sometimes occur within protected areas, so that anthropogenic influences on carnivore biology are not necessarily confined to unprotected areas. In this study we evaluated associations between human infrastructure and related activity and space use of spotted hyaenas within one of the largest protected areas in South Africa, the Kruger National Park. Home range size was smaller for the dominant female of a clan living in close proximity to humans than that of the dominant female of a clan without direct access to human infrastructure. The home range including human infrastructure was also used less evenly during the night, presumably when the animals were active. Within this home range, a village area was preferred during the night, when the least modified areas within the village were preferred and administration and highly modified areas were avoided. During the day, however, there were no preference or avoidance of the village area, but all habitats except unmodified habitats within the village area were avoided. We suggest that human infrastructure and associated activity influenced hyaena space use, primarily through alterations in the spatial distribution of food. However, these effects may have been indirectly caused by habitat modification that generated favourable hunting habitat rather than a direct effect caused by access to human food such as garbage. Because of the often pivotal effects of apex predators in terrestrial ecosystems, we encourage further work aimed to quantify how human presence influences large carnivores and associated ecosystem processes within protected areas.

  • 13. Bergh, Johan
    et al.
    Zetterstrom, Per
    Andersen, Peter M.
    Brannstrom, Thomas
    Graffmo, Karin S.
    Jonsson, P. Andreas
    Lang, Lisa
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Danielsson, Jens
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Oliveberg, Mikael
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Marklund, Stefan L.
    Structural and kinetic analysis of protein-aggregate strains in vivo using binary epitope mapping2015Inngår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 112, nr 14, s. 4489-4494Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Despite considerable progress in uncovering the molecular details of protein aggregation in vitro, the cause and mechanism of protein-aggregation disease remain poorly understood. One reason is that the amount of pathological aggregates in neural tissue is exceedingly low, precluding examination by conventional approaches. We present here a method for determination of the structure and quantity of aggregates in small tissue samples, circumventing the above problem. The method is based on binary epitope mapping using anti-peptide antibodies. We assessed the usefulness and versatility of the method in mice modeling the neurodegenerative disease amyotrophic lateral sclerosis, which accumulate intracellular aggregates of superoxide dismutase-1. Two strains of aggregates were identified with different structural architectures, molecular properties, and growth kinetics. Both were different from superoxide dismutase-1 aggregates generated in vitro under a variety of conditions. The strains, which seem kinetically under fragmentation control, are associated with different disease progressions, complying with and adding detail to the growing evidence that seeding, infectivity, and strain dependence are unifying principles of neurodegenerative disease.

  • 14. Berthelsen, Hanne
    et al.
    Hakanen, Jari J.
    Westerlund, Hugo
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Stressforskningsinstitutet.
    Copenhagen Psychosocial Questionnaire - A validation study using the Job Demand-Resources model2018Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, nr 4, artikkel-id e0196450Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim

    This study aims at investigating the nomological validity of the Copenhagen Psychosocial Questionnaire (COPSOQ II) by using an extension of the Job Demands-Resources (JD-R) model with aspects of work ability as outcome.

    Material and methods

    The study design is cross-sectional. All staff working at public dental organizations in four regions of Sweden were invited to complete an electronic questionnaire (75% response rate, n = 1345). The questionnaire was based on COPSOQ II scales, the Utrecht Work Engagement scale, and the one-item Work Ability Score in combination with a proprietary item. The data was analysed by Structural Equation Modelling.

    Results

    This study contributed to the literature by showing that: A) The scale characteristics were satisfactory and the construct validity of COPSOQ instrument could be integrated in the JD-R framework; B) Job resources arising from leadership may be a driver of the two processes included in the JD-R model; and C) Both the health impairment and motivational processes were associated with WA, and the results suggested that leadership may impact WA, in particularly by securing task resources.

    Conclusion

    In conclusion, the nomological validity of COPSOQ was supported as the JD-R model can be operationalized by the instrument. This may be helpful for transferral of complex survey results and work life theories to practitioners in the field.

  • 15. Blank, Malou
    et al.
    Sjögren, Karl-Göran
    Knipper, Corina
    Frei, Karin M.
    Storå, Jan
    Stockholms universitet, Humanistiska fakulteten, Institutionen för arkeologi och antikens kultur.
    Isotope values of the bioavailable strontium in inland southwestern Sweden-A baseline for mobility studies2018Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, nr 10, artikkel-id e0204649Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The inland area of southwestern Sweden is well known for its well-preserved archaeological animal and human remains dating back to the Mesolithic and Neolithic (10000-4000 and 4000-1700 BC). They allow application of multiple bioarchaeological methods, giving insights into various and complementary aspects of prehistoric human life, as well as economic and social structures. One important aspect concerns human mobility and its relation to social networks and to circulation of objects. Here, strontium isotope analysis plays a crucial role. The present study aims to construct a strontium isotope baseline of southwestern Sweden with considerably greater coverage and higher resolution than previously published data. As the region has been affected by glacial events, the relation between bedrock geology and isotope signals of the bioavailable strontium in such areas is given special attention. We determined strontium isotope ratios for 61 water and five archaeological animal samples, and combined the data with previous measurements of two water and 21 non-domestic faunal samples. The results reveal a complex pattern. Several areas with distinct baseline ranges can be distinguished, although with overlaps between some of them. Overall, the bioavailable strontium isotope signals mirror the basement geology of the region. The highest ratios occur in the geologically oldest eastern parts of the Precambrian terrain, while lower ratios are found in the western part, and the lowest ratios occur in the youngest Paleozoic areas. At the same time, there are minor deviations compared to the underlying bedrock, due to glacial transport, overlying sediments, and local intrusions of younger rocks. The background data set now available allows for more nuanced and detailed interpretations of human and animal mobility in the region, in particular by identification of subregions with differing strontium isotope ratios within the Precambrian province. Also, we can now identify long distance mobility with greater confidence.

  • 16.
    Blasiak, Robert
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholm Resilience Centre. The University of Tokyo, Japan.
    Jouffray, Jean-Baptiste
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholm Resilience Centre. Royal Swedish Academy of Sciences, Sweden.
    Wabnitz, Colette C. C.
    Sundström, Emma
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholm Resilience Centre.
    Österblom, Henrik
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholm Resilience Centre.
    Corporate control and global governance of marine genetic resources2018Inngår i: Science Advances, ISSN 0036-8156, E-ISSN 2375-2548, Vol. 4, nr 6, artikkel-id eaar5237Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Who owns ocean biodiversity? This is an increasingly relevant question, given the legal uncertainties associated with the use of genetic resources from areas beyond national jurisdiction, which cover half of the Earth's surface. We accessed 38 million records of genetic sequences associated with patents and created a database of 12,998 sequences extracted from 862 marine species. We identified >1600 sequences from 91 species associated with deepsea and hydrothermal vent systems, reflecting commercial interest in organisms from remote ocean areas, as well as a capacity to collect and use the genes of such species. A single corporation registered 47% of all marine sequences included in gene patents, exceeding the combined share of 220 other companies (37%). Universities and their commercialization partners registered 12%. Actors located or headquartered in 10 countries registered 98% of all patent sequences, and 165 countries were unrepresented. Our findings highlight the importance of inclusive participation by all states in international negotiations and the urgency of clarifying the legal regime around access and benefit sharing of marine genetic resources. We identify a need for greater transparency regarding species provenance, transfer of patent ownership, and activities of corporations with a disproportionate influence over the patenting of marine biodiversity. We suggest that identifying these key actors is a critical step toward encouraging innovation, fostering greater equity, and promoting better ocean stewardship.

  • 17. Brand, Stephen K.
    et al.
    Schmidt, Joel E.
    Deem, Michael W.
    Daeyaert, Frits
    Ma, Yanhang
    Terasaki, Osamu
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK). ShanghaiTech University, China.
    Orazov, Marat
    Davis, Mark E.
    Enantiomerically enriched, polycrystalline molecular sieves2017Inngår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 114, nr 20, s. 5101-5106Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Zeolite and zeolite-like molecular sieves are being used in a large number of applications such as adsorption and catalysis. Achievement of the long-standing goal of creating a chiral, polycrystalline molecular sieve with bulk enantioenrichment would enable these materials to perform enantioselective functions. Here, we report the synthesis of enantiomerically enriched samples of a molecular sieve. Enantiopure organic structure directing agents are designed with the assistance of computational methods and used to synthesize enantioenriched, polycrystalline molecular sieve samples of either enantiomer. Computational results correctly predicted which enantiomer is obtained, and enantiomeric enrichment is proven by high-resolution transmission electron microscopy. The enantioenriched and racemic samples of the molecular sieves are tested as adsorbents and heterogeneous catalysts. The enantioenriched molecular sieves show enantioselectivity for the ring opening reaction of epoxides and enantioselective adsorption of 2-butanol (the R enantiomer of the molecular sieve shows opposite and approximately equal enantioselectivity compared with the S enantiomer of the molecular sieve, whereas the racemic sample of the molecular sieve shows no enantioselectivity).

  • 18. Bratman, Gregory N.
    et al.
    Anderson, Christopher B.
    Berman, Marc G.
    Cochran, Bobby
    de Vries, Sjerp
    Flanders, Jon
    Folke, Carl
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholm Resilience Centre. Royal Swedish Academy of Sciences, Sweden.
    Frumkin, Howard
    Gross, James J.
    Hartig, Terry
    Kahn, Peter H.
    Kuo, Ming
    Lawler, Joshua J.
    Levin, Phillip S.
    Lindahl, Therese
    Meyer-Lindenberg, Andreas
    Mitchell, Richard
    Ouyang, Zhiyun
    Roe, Jenny
    Scarlett, Lynn
    Smith, Jeffrey R.
    van den Bosch, Matilda
    Wheeler, Benedict W.
    White, Mathew P.
    Zheng, Hua
    Daily, Gretchen C.
    Nature and mental health: An ecosystem service perspective2019Inngår i: Science Advances, E-ISSN 2375-2548, Vol. 5, nr 7, artikkel-id eaax0903Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    A growing body of empirical evidence is revealing the value of nature experience for mental health. With rapid urbanization and declines in human contact with nature globally, crucial decisions must be made about how to preserve and enhance opportunities for nature experience. Here, we first provide points of consensus across the natural, social, and health sciences on the impacts of nature experience on cognitive functioning, emotional well-being, and other dimensions of mental health. We then show how ecosystem service assessments can be expanded to include mental health, and provide a heuristic, conceptual model for doing so.

  • 19. Burlacu, Elena
    et al.
    Lackmann, Fredrik
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Aguilar, Lisbeth-Carolina
    Belikov, Sergey
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    van Nues, Rob
    Trahan, Christian
    Hector, Ralph D.
    Dominelli-Whiteley, Nicholas
    Cockroft, Scott L.
    Wieslander, Lars
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Oeffinger, Marlene
    Granneman, Sander
    High-throughput RNA structure probing reveals critical folding events during early 60S ribosome assembly in yeast2017Inngår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 8, artikkel-id 714Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    While the protein composition of various yeast 60S ribosomal subunit assembly intermediates has been studied in detail, little is known about ribosomal RNA (rRNA) structural rearrangements that take place during early 60S assembly steps. Using a high-throughput RNA structure probing method, we provide nucleotide resolution insights into rRNA structural rearrangements during nucleolar 60S assembly. Our results suggest that many rRNA-folding steps, such as folding of 5.8S rRNA, occur at a very specific stage of assembly, and propose that downstream nuclear assembly events can only continue once 5.8S folding has been completed. Our maps of nucleotide flexibility enable making predictions about the establishment of protein-rRNA interactions, providing intriguing insights into the temporal order of protein-rRNA as well as long-range inter-domain rRNA interactions. These data argue that many distant domains in the rRNA can assemble simultaneously during early 60S assembly and underscore the enormous complexity of 60S synthesis.

  • 20. Bögli, Sabine
    et al.
    Brown, B. Malcolm
    Marletta, Marco
    Tretter, Christiane
    Stockholms universitet, Naturvetenskapliga fakulteten, Matematiska institutionen. Universität Bern, Switzerland.
    Wagenhofer, Markus
    Guaranteed resonance enclosures and exclosures for atoms and molecules2014Inngår i: Proceedings of the Royal Society. Mathematical, Physical and Engineering Sciences, ISSN 1364-5021, E-ISSN 1471-2946, Vol. 470, nr 2171, artikkel-id 20140488Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper, we confirm, with absolute certainty, a conjecture on a certain oscillatory behaviour of higher auto-ionizing resonances of atoms and molecules beyond a threshold. These results not only definitely settle a more than 30 year old controversy in Rittby et al. (1981 Phys. Rev. A 24, 1636-1639 (doi: 10.1103/PhysRevA.24.1636)) and Korsch et al. (1982 Phys. Rev. A 26, 1802-1803 (doi:10.1103/PhysRevA.26.1802)), but also provide new and reliable information on the threshold. Our interval-arithmetic-based method allows one, for the first time, to enclose and to exclude resonances with guaranteed certainty. The efficiency of our approach is demonstrated by the fact that we are able to show that the approximations in Rittby et al. (1981 Phys. Rev. A 24, 1636-1639 (doi:10.1103/PhysRevA.24.1636)) do lie near true resonances, whereas the approximations of higher resonances in Korsch et al. (1982 Phys. Rev. A 26, 1802-1803 (doi:10.1103/PhysRevA.26.1802)) do not, and further that there exist two new pairs of resonances as suggested in Abramov et al. (2001 J. Phys. A 34, 57-72 (doi:10.1088/0305-4470/34/1/304)).

  • 21. Büntgen, Ulf
    et al.
    Wacker, Lukas
    Galvan, J. Diego
    Arnold, Stephanie
    Arseneault, Dominique
    Baillie, Michael
    Beer, Jurg
    Bernabei, Mauro
    Bleicher, Niels
    Boswijk, Gretel
    Brauning, Achim
    Carrer, Marco
    Charpentier Ljungqvist, Fredrik
    Stockholms universitet, Humanistiska fakulteten, Historiska institutionen. University of Cambridge, UK.
    Cherubini, Paolo
    Christl, Marcus
    Christie, Duncan A.
    Clark, Peter W.
    Cook, Edward R.
    D'Arrigo, Rosanne
    Davi, Nicole
    Eggertsson, Olafur
    Esper, Jan
    Fowler, Anthony M.
    Gedalof, Ze'ev
    Gennaretti, Fabio
    Griessinger, Jussi
    Grissino-Mayer, Henri
    Grudd, Hakan
    Gunnarson, Björn E.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi.
    Hantemirov, Rashit
    Herzig, Franz
    Hessl, Amy
    Heussner, Karl-Uwe
    Jull, A. J. Timothy
    Kukarskih, Vladimir
    Kirdyanov, Alexander
    Kolar, Tomas
    Krusic, Paul J.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi. University of Cambridge, UK; Navarino Environmental Observatory, Greece.
    Kyncl, Tomas
    Lara, Antonio
    LeQuesne, Carlos
    Linderholm, Hans W.
    Loader, Neil J.
    Luckman, Brian
    Miyake, Fusa
    Myglan, Vladimir S.
    Nicolussi, Kurt
    Oppenheimer, Clive
    Palmer, Jonathan
    Panyushkina, Irina
    Pederson, Neil
    Rybnicek, Michal
    Schweingruber, Fritz H.
    Seim, Andrea
    Sigl, Michael
    Churakova (Sidorova), Olga
    Speer, James H.
    Synal, Hans-Arno
    Tegel, Willy
    Treydte, Kerstin
    Villalba, Ricardo
    Wiles, Greg
    Wilson, Rob
    Winship, Lawrence J.
    Wunder, Jan
    Yang, Bao
    Young, Giles H. F.
    Tree rings reveal globally coherent signature of cosmogenic radiocarbon events in 774 and 993 CE2018Inngår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 9, artikkel-id 3605Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Though tree-ring chronologies are annually resolved, their dating has never been independently validated at the global scale. Moreover, it is unknown if atmospheric radiocarbon enrichment events of cosmogenic origin leave spatiotemporally consistent fingerprints. Here we measure the C-14 content in 484 individual tree rings formed in the periods 770-780 and 990-1000 CE. Distinct C-14 excursions starting in the boreal summer of 774 and the boreal spring of 993 ensure the precise dating of 44 tree-ring records from five continents. We also identify a meridional decline of 11-year mean atmospheric radiocarbon concentrations across both hemispheres. Corroborated by historical eye-witness accounts of red auroras, our results suggest a global exposure to strong solar proton radiation. To improve understanding of the return frequency and intensity of past cosmic events, which is particularly important for assessing the potential threat of space weather on our society, further annually resolved C-14 measurements are needed.

  • 22.
    Campennì, Marco
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholm Resilience Centre.
    Schino, Gabriele
    Symmetry-based reciprocity: evolutionary constraints on a proximate mechanism2016Inngår i: PeerJ, ISSN 2167-8359, E-ISSN 2167-8359, Vol. 4, artikkel-id e1812Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background. While the evolution of reciprocal cooperation has attracted an enormous attention, the proximate mechanisms underlying the ability of animals to cooperate reciprocally are comparatively neglected. Symmetry-based reciprocity is a hypothetical proximate mechanism that has been suggested to be widespread among cognitively unsophisticated animals. Methods. We developed two agent-baseds model of symmetry-based reciprocity (one relying on an arbitrary tag and the other on interindividual proximity) and tested their ability both to reproduce significant emergent features of cooperation in group living animals and to promote the evolution of cooperation. Results. Populations formed by', agents adopting symmetry-based reciprocity showed differentiated social relationships and a positive correlation between cooperation given and received: two common aspects of animal cooperation. However, when reproduction and selection across multiple generations were added to the models, agents adopting symmetry-based reciprocity were outcompeted by selfish agents that never cooperated. Discussion. In order to evolve, hypothetical proximate mechanisms must be able to from stand competition alternative strategies. While the results of our simulations require confirmation using analytical methods, we provisionally suggest symmetry based reciprocity is to be abandoned as a possible proximate mechanism underlying the ability of animals to reciprocate cooperative interactions.

  • 23.
    Cannon, Barbara
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Wenner-Grens institut.
    Nedergaard, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Wenner-Grens institut.
    Cell biology: Neither brown nor white.2012Inngår i: Nature, ISSN 1476-4687, Vol. 488, nr 7411, s. 286-287Artikkel i tidsskrift (Fagfellevurdert)
  • 24.
    Cannon, Barbara
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Wenner-Grens institut.
    Nedergaard, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Wenner-Grens institut.
    Yes, even human brown fat is on fire!2012Inngår i: Journal of Clinical Investigation, ISSN 0021-9738, E-ISSN 1558-8238, Vol. 122, nr 2, s. 486-489Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    That adult humans possess brown fat is now accepted - but is the brown fat metabolically active? Does human brown fat actually combust fat to release heat? In this issue of the JCI, Ouellet et al. demonstrate that metabolism in brown fat really is increased when adult humans are exposed to cold. This boosts the possibility that calorie combustion in brown fat may be of significance for our metabolism and, correspondingly, that the absence of brown fat may increase our proneness to obesity - provided that brown fat becomes activated not only by cold but also through food-related stimuli.

  • 25. Carpenter, Stephen R.
    et al.
    Brock, William A.
    Folke, Carl
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholm Resilience Centre. Royal Swedish Academy of Sciences, Sweden.
    van Nes, Egbert H.
    Scheffer, Marten
    Allowing variance may enlarge the safe operating space for exploited ecosystems2015Inngår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 112, nr 46, s. 14384-14389Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Variable flows of food, water, or other ecosystem services complicate planning. Management strategies that decrease variability and increase predictability may therefore be preferred. However, actions to decrease variance over short timescales (2-4 y), when applied continuously, may lead to long-term ecosystem changes with adverse consequences. We investigated the effects of managing short-term variance in three well-understood models of ecosystem services: lake eutrophication, harvest of a wild population, and yield of domestic herbivores on a rangeland. In all cases, actions to decrease variance can increase the risk of crossing critical ecosystem thresholds, resulting in less desirable ecosystem states. Managing to decrease short-term variance creates ecosystem fragility by changing the boundaries of safe operating spaces, suppressing information needed for adaptive management, cancelling signals of declining resilience, and removing pressures that may build tolerance of stress. Thus, the management of variance interacts strongly and inseparably with the management of resilience. By allowing for variation, learning, and flexibility while observing change, managers can detect opportunities and problems as they develop while sustaining the capacity to deal with them.

  • 26. Carreras-Puigvert, Jordi
    et al.
    Zitnik, Marinka
    Jemth, Ann-Sofie
    Carter, Megan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Unterlass, Judith E.
    Hallström, Björn
    Loseva, Olga
    Karem, Zhir
    Calderón-Montaño, José Manuel
    Lindskog, Cecilia
    Edqvist, Per-Henrik
    Matuszewski, Damian J.
    Blal, Hammou Ait
    Berntsson, Ronnie P. A.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Häggblad, Maria
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Martens, Ulf
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Studham, Matthew
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Lundgren, Bo
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Wählby, Carolina
    Sonnhammer, Erik L. L.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Lundberg, Emma
    Stenmark, Pål
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Zupan, Blaz
    Helleday, Thomas
    A comprehensive structural, biochemical and biological profiling of the human NUDIX hydrolase family2017Inngår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 8, artikkel-id 1541Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The NUDIX enzymes are involved in cellular metabolism and homeostasis, as well as mRNA processing. Although highly conserved throughout all organisms, their biological roles and biochemical redundancies remain largely unclear. To address this, we globally resolve their individual properties and inter-relationships. We purify 18 of the human NUDIX proteins and screen 52 substrates, providing a substrate redundancy map. Using crystal structures, we generate sequence alignment analyses revealing four major structural classes. To a certain extent, their substrate preference redundancies correlate with structural classes, thus linking structure and activity relationships. To elucidate interdependence among the NUDIX hydrolases, we pairwise deplete them generating an epistatic interaction map, evaluate cell cycle perturbations upon knockdown in normal and cancer cells, and analyse their protein and mRNA expression in normal and cancer tissues. Using a novel FUSION algorithm, we integrate all data creating a comprehensive NUDIX enzyme profile map, which will prove fundamental to understanding their biological functionality.

  • 27.
    Carter, Megan
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Jemth, Ann-Sofie
    Hagenkort, Anna
    Page, Brent D. G.
    Gustafsson, Robert
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Griese, Julia J.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Gad, Helge
    Valerie, Nicholas C. K.
    Desroses, Matthieu
    Boström, Johan
    Berglund, Ulrika Warpman
    Helleday, Thomas
    Stenmark, Pål
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Crystal structure, biochemical and cellular activities demonstrate separate functions of MTH1 and MTH22015Inngår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 6, artikkel-id 7871Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Deregulated redox metabolism in cancer leads to oxidative damage to cellular components including deoxyribonucleoside triphosphates (dNTPs). Targeting dNTP pool sanitizing enzymes, such as MTH1, is a highly promising anticancer strategy. The MTH2 protein, known as NUDT15, is described as the second human homologue of bacterial MutT with 8-oxo-dGTPase activity. We present the first NUDT15 crystal structure and demonstrate that NUDT15 prefers other nucleotide substrates over 8-oxo-dGTP. Key structural features are identified that explain different substrate preferences for NUDT15 and MTH1. We find that depletion of NUDT15 has no effect on incorporation of 8-oxo-dGTP into DNA and does not impact cancer cell survival in cell lines tested. NUDT17 and NUDT18 were also profiled and found to have far less activity than MTH1 against oxidized nucleotides. We show that NUDT15 is not a biologically relevant 8-oxo-dGTPase, and that MTH1 is the most prominent sanitizer of the cellular dNTP pool known to date.

  • 28.
    Cavazzana, Annachiara
    et al.
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen. TU Dresden, Germany.
    Röhrborn, Anja
    Garthus-Niegel, Susan
    Larsson, Maria
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Psykologiska institutionen, Perception och psykofysik.
    Hummel, Thomas
    Croy, Ilona
    Sensory-specific impairment among older people: An investigation using both sensory thresholds and subjective measures across the five senses2018Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, nr 8, artikkel-id e0202969Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Age-related sensory impairment is a slow and gradual progress, which affects multiple modalities. Two contradictory hypotheses exist about the age-related decline of sensory thresholds. The common factor theory assumes one underlying factor-which accounts for the loss of several sensory modalities simultaneously-and the specific factor theory predicts that the sensory decline is uncorrelated between different modalities. In this study, we aimed to explore whether (i) there is a common factor of sensory thresholds in older people, (ii) older people assume that sensory decline in one modality also affects other modalities, (iii) there is a relation between sensory threshold and the subjective assessment of sensory function. This was accomplished by collecting both threshold measures and self-reported ratings for smell, hearing, taste, vision, and touch function in a group of 104 older people (mean age: 67.2 years; SD: 9.85; range: 50-100 years). Results indicated that there was no common factor of sensory thresholds, hence an impairment in one modality did not necessarily imply a shortfall in other modalities. In contrast, our results suggested one or two common factor(s) for the participants' ratings. Participants who reported a diminished function in one sense tended to generalize this rating to the other senses as well. The correspondence between subjective ratings and sensory thresholds was relatively good for vision and audition, although no correlations were observed for the other domains. These findings have implications for clinicians, suggesting that subjective measures should be combined with sensory threshold measurements when evaluating sensory dysfunction. Also, these data convey a positive message for older people and their physicians by showing that loss in one sensory modality does not necessarily generalize to losses across all sensory modalities.

  • 29. Cebula, Marcus
    et al.
    Turan, Ilke Simsek
    Sjödin, Birgitta
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för neurokemi.
    Thulasingam, Madhuranayaki
    Brock, Joseph
    Chmyrov, Volodymyr
    Widengren, Jerker
    Abe, Hiroshi
    Mannervik, Bengt
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för neurokemi.
    Haeggström, Jesper Z.
    Rinaldo-Matthis, Agnes
    Akkaya, Engin U.
    Morgenstern, Ralf
    Catalytic Conversion of Lipophilic Substrates by Phase constrained Enzymes in the Aqueous or in the Membrane Phase2016Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, artikkel-id 38316Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Both soluble and membrane-bound enzymes can catalyze the conversion of lipophilic substrates. The precise substrate access path, with regard to phase, has however, until now relied on conjecture from enzyme structural data only (certainly giving credible and valuable hypotheses). Alternative methods have been missing. To obtain the first experimental evidence directly determining the access paths (of lipophilic substrates) to phase constrained enzymes we here describe the application of a BODIPY-derived substrate (PS1). Using this tool, which is not accessible to cytosolic enzymes in the presence of detergent and, by contrast, not accessible to membrane embedded enzymes in the absence of detergent, we demonstrate that cytosolic and microsomal glutathione transferases (GSTs), both catalyzing the activation of PS1, do so only within their respective phases. This approach can serve as a guideline to experimentally validate substrate access paths, a fundamental property of phase restricted enzymes. Examples of other enzyme classes with members in both phases are xenobiotic-metabolizing sulphotransferases/UDP-glucuronosyl transferases or epoxide hydrolases. Since specific GSTs have been suggested to contribute to tumor drug resistance, PS1 can also be utilized as a tool to discriminate between phase constrained members of these enzymes by analyzing samples in the absence and presence of Triton X-100.

  • 30. Chen, Geng
    et al.
    Aharon, Nati
    Sun, Yong-Nan
    Zhang, Zi-Huai
    Zhang, Wen-Hao
    He, De-Yong
    Tang, Jian-Shun
    Xu, Xiao-Ye
    Kedem, Yaron
    Stockholms universitet, Naturvetenskapliga fakulteten, Fysikum.
    Li, Chuan-Feng
    Guo, Guang-Can
    Heisenberg-scaling measurement of the single-photon Kerr non-linearity using mixed states2018Inngår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 9, artikkel-id 93Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Improving the precision of measurements is a significant scientific challenge. Previous works suggest that in a photon-coupling scenario the quantum fisher information shows a quantum-enhanced scaling of N-2, which in theory allows a better-than-classical scaling in practical measurements. In this work, utilizing mixed states with a large uncertainty and a post-selection of an additional pure system, we present a scheme to extract this amount of quantum fisher information and experimentally attain a practical Heisenberg scaling. We performed a measurement of a single-photon's Kerr non-linearity with a Heisenberg scaling, where an ultra-small Kerr phase of. 6 x 10(-8) rad was observed with a precision of similar or equal to 3.6 x 10(-10) rad. From the use of mixed states, the upper bound of quantum fisher information is improved to 2N(2). Moreover, by using an imaginary weak-value the scheme is robust to noise originating from the self-phase modulation.

  • 31. Chernobrovkin, Alexey
    et al.
    Marin-Vicente, Consuelo
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut. Karolinska Institutet, Sweden .
    Visa, Neus
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Zubarev, Roman A.
    Functional Identification of Target by Expression Proteomics (FITExP) reveals protein targets and highlights mechanisms of action of small molecule drugs2015Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, artikkel-id 11176Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Phenomenological screening of small molecule libraries for anticancer activity yields potentially interesting candidate molecules, with a bottleneck in the determination of drug targets and the mechanism of anticancer action. We have found that, for the protein target of a small-molecule drug, the abundance change in late apoptosis is exceptional compared to the expectations based on the abundances of co-regulated proteins. Based on this finding, a novel method to drug target deconvolution is proposed. In a proof of principle experiment, the method yielded known targets of several common anticancer agents among a few (often, just one) likely candidates identified in an unbiased way from cellular proteome comprising more than 4,000 proteins. A validation experiment with a different set of cells and drugs confirmed the findings. As an additional benefit, mapping most specifically regulated proteins on known protein networks highlighted the mechanism of drug action. The new method, if proven to be general, can significantly shorten drug target identification, and thus facilitate the emergence of novel anticancer treatments.

  • 32. Cho, Hae Sung
    et al.
    Deng, Hexiang
    Miyasaka, Keiichi
    Dong, Zhiyue
    Cho, Minhyung
    Neimark, Alexander V.
    Kang, Jeung Ku
    Yaghi, Omar M.
    Terasaki, Osamu
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK). Graduate School of Energy, Environment, Water and Sustainability, South Korea.
    Extra adsorption and adsorbate superlattice formation in metal-organic frameworks2015Inngår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 527, nr 7579, s. 503-U193Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Metal-organic frameworks (MOFs) have a high internal surface area and widely tunable composition(1,2), which make them useful for applications involving adsorption, such as hydrogen, methane or carbon dioxide storage(3-9). The selectivity and uptake capacity of the adsorption process are determined by interactions involving the adsorbates and their porous host materials. But, although the interactions of adsorbate molecules with the internal MOF surface(10-17) and also amongst themselves within individual pores(18-22) have been extensively studied, adsorbate-adsorbate interactions across pore walls have not been explored. Here we show that local strain in the MOF, induced by pore filling, can give rise to collective and long-range adsorbate-adsorbate interactions and the formation of adsorbate superlattices that extend beyond an original MOF unit cell. Specifically, we use in situ small-angle X-ray scattering to track and map the distribution and ordering of adsorbate molecules in five members of the mesoporous MOF-74 series along entire adsorption-desorption isotherms. We find in all cases that the capillary condensation that fills the pores gives rise to the formation of 'extra adsorption domains'-that is, domains spanning several neighbouring pores, which have a higher adsorbate density than non-domain pores. In the case of one MOF, IRMOF-74-V-hex, these domains form a superlattice structure that is difficult to reconcile with the prevailing view of pore-filling as a stochastic process. The visualization of the adsorption process provided by our data, with clear evidence for initial adsorbate aggregation in distinct domains and ordering before an even distribution is finally reached, should help to improve our understanding of this process and may thereby improve our ability to exploit it practically.

  • 33.
    Cottman, Petter
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Cykelolyckor, orsaksfaktorer och samband: Ett metodtest i GIS för att hitta ett eventuellt samband mellan cykelolyckor och platsen där de sker2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
  • 34. Cova, Ilaria
    et al.
    Clerici, Francesca
    Rossi, Annalia
    Cucumo, Valentina
    Ghiretti, Roberta
    Maggiore, Laura
    Pomati, Simone
    Galimberti, Daniela
    Scarpini, Elio
    Mariani, Claudio
    Caracciolo, Barbara
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    Weight Loss Predicts Progression of Mild Cognitive Impairment to Alzheimer's Disease2016Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, nr 3, artikkel-id e0151710Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background Weight loss is common in people with Alzheimer's disease (AD) and it could be a marker of impending AD in Mild Cognitive Impairment (MCI) and improve prognostic accuracy, if accelerated progression to AD would be shown.

    Aims To assess weight loss as a predictor of dementia and AD in MCI.

    Methods One hundred twenty-five subjects with MCI (age 73.8 +/- 7.1 years) were followed for an average of 4 years. Two weight measurements were carried out at a minimum time interval of one year. Dementia was defined according to DSM-IV criteria and AD according to NINCDS-ADRDA criteria. Weight loss was defined as a >= 4% decrease in baseline weight.

    Results Fifty-three (42.4%) MCI progressed to dementia, which was of the AD-type in half of the cases. Weight loss was associated with a 3.4-fold increased risk of dementia (95% CI = 1.5-6.9) and a 3.2-fold increased risk of AD (95% CI = 1.4-8.3). In terms of years lived without disease, weight loss was associated to a 2.3 and 2.5 years earlier onset of dementia and AD.

    Conclusions Accelerated progression towards dementia and AD is expected when weight loss is observed in MCI patients. Weight should be closely monitored in elderly with mild cognitive impairment.

  • 35.
    Dahlin, Paul
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik. Royal Institute of Technology (KTH), Sweden.
    Srivastava, Vaibhav
    Ekengren, Sophia
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik. Royal Institute of Technology (KTH), Sweden.
    Mckee, Lauren S.
    Bulone, Vincent
    Comparative analysis of sterol acquisition in the oomycetes Saprolegnia parasitica and Phytophthora infestans2017Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, nr 2, artikkel-id e0170873Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The oomycete class includes pathogens of animals and plants which are responsible for some of the most significant global losses in agriculture and aquaculture. There is a need to replace traditional chemical means of controlling oomycete growth with more targeted approaches, and the inhibition of sterol synthesis is one promising area. To better direct these efforts, we have studied sterol acquisition in two model organisms: the sterol-autotrophic Saprolegnia parasitica, and the sterol-heterotrophic Phytophthora infestans. We first present a comprehensive reconstruction of a likely sterol synthesis pathway for S. parasitica, causative agent of the disease saprolegniasis in fish. This pathway shows multiple potential routes of sterol synthesis, and draws on several avenues of new evidence: bioinformatic mining for genes with sterol-related functions, expression analysis of these genes, and analysis of the sterol profiles in mycelium grown in different media. Additionally, we explore the extent to which P. infestans, which causes the late blight in potato, can modify exogenously provided sterols. We consider whether the two very different approaches to sterol acquisition taken by these pathogens represent any specific survival advantages or potential drug targets.

  • 36.
    Daley, Daniel O.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Skoglund, Ulf
    Söderström, Bill
    FtsZ does not initiate membrane constriction at the onset of division2016Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, artikkel-id 33138Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The source of constriction required for division of a bacterial cell remains enigmatic. FtsZ is widely believed to be a key player, because in vitro experiments indicate that it can deform liposomes when membrane tethered. However in vivo evidence for such a role has remained elusive as it has been challenging to distinguish the contribution of FtsZ from that of peptidoglycan-ingrowth. To differentiate between these two possibilities we studied the early stages of division in Escherichia coli, when FtsZ is present at the division site but peptidoglycan synthesizing enzymes such as FtsI and FtsN are not. Our approach was to use correlative cryo-fluorescence and cryo-electron microscopy (cryo-CLEM) to monitor the localization of fluorescently labeled FtsZ, FtsI or FtsN correlated with the septal ultra-structural geometry in the same cell. We noted that the presence of FtsZ at the division septum is not sufficient to deform membranes. This observation suggests that, although FtsZ can provide a constrictive force, the force is not substantial at the onset of division. Conversely, the presence of FtsN always correlated with membrane invagination, indicating that allosteric activation of peptidoglycan ingrowth is the trigger for constriction of the cell envelope during cell division in E. coli.

  • 37. Dall'Osto, M.
    et al.
    Beddows, D. C. S.
    Asmi, A.
    Poulain, L.
    Hao, L.
    Freney, E.
    Allan, J. D.
    Canagaratna, M.
    Crippa, M.
    Bianchi, F.
    de Leeuw, G.
    Eriksson, A.
    Swietlicki, E.
    Hansson, Hans Christen
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Henzing, J. S.
    Granier, C.
    Zemankova, K.
    Laj, P.
    Onasch, T.
    Prevot, A.
    Putaud, J. P.
    Sellegri, K.
    Vidal, M.
    Virtanen, A.
    Simo, R.
    Worsnop, D.
    O'Dowd, C.
    Kulmala, M.
    Harrison, Roy M.
    Novel insights on new particle formation derived from a pan-european observing system2018Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, artikkel-id 1482Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The formation of new atmospheric particles involves an initial step forming stable clusters less than a nanometre in size (<similar to 1 nm), followed by growth into quasi-stable aerosol particles a few nanometres (similar to 1-10 nm) and larger (>similar to 10 nm). Although at times, the same species can be responsible for both processes, it is thought that more generally each step comprises differing chemical contributors. Here, we present a novel analysis of measurements from a unique multi-station ground-based observing system which reveals new insights into continental-scale patterns associated with new particle formation. Statistical cluster analysis of this unique 2-year multi-station dataset comprising size distribution and chemical composition reveals that across Europe, there are different major seasonal trends depending on geographical location, concomitant with diversity in nucleating species while it seems that the growth phase is dominated by organic aerosol formation. The diversity and seasonality of these events requires an advanced observing system to elucidate the key processes and species driving particle formation, along with detecting continental scale changes in aerosol formation into the future.

  • 38.
    Daume, Stefan
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholm Resilience Centre. Georg-August-University Göttingen, Germany; Swedish Museum of Natural History, Sweden.
    Galaz, Victor
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholm Resilience Centre.
    Anyone Know What Species This Is? - Twitter Conversations as Embryonic Citizen Science Communities2016Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, nr 3, artikkel-id e0151387Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Social media like blogs, micro-blogs or social networks are increasingly being investigated and employed to detect and predict trends for not only social and physical phenomena, but also to capture environmental information. Here we argue that opportunistic biodiversity observations published through Twitter represent one promising and until now unexplored example of such data mining. As we elaborate, it can contribute to real-time information to traditional ecological monitoring programmes including those sourced via citizen science activities. Using Twitter data collected for a generic assessment of social media data in ecological monitoring we investigated a sample of what we denote biodiversity observations with species determination requests (N = 191). These entail images posted as messages on the micro-blog service Twitter. As we show, these frequently trigger conversations leading to taxonomic determinations of those observations. All analysed Tweets were posted with species determination requests, which generated replies for 64% of Tweets, 86% of those contained at least one suggested determination, of which 76% were assessed as correct. All posted observations included or linked to images with the overall image quality categorised as satisfactory or better for 81% of the sample and leading to taxonomic determinations at the species level in 71% of provided determinations. We claim that the original message authors and conversation participants can be viewed as implicit or embryonic citizen science communities which have to offer valuable contributions both as an opportunistic data source in ecological monitoring as well as potential active contributors to citizen science programmes.

  • 39. Davies, Gail
    et al.
    Lam, Max
    Harris, Sarah E.
    Trampush, Joey W.
    Luciano, Michelle
    Hill, W. David
    Hagenaars, Saskia P.
    Ritchie, Stuart J.
    Marioni, Riccardo E.
    Fawns-Ritchie, Chloe
    Liewald, David C. M.
    Okely, Judith A.
    Ahola-Olli, Ari V.
    Barnes, Catriona L. K.
    Bertram, Lars
    Bis, Joshua C.
    Burdick, Katherine E.
    Christoforou, Andrea
    DeRosse, Pamela
    Djurovic, Srdjan
    Espeseth, Thomas
    Giakoumaki, Stella
    Giddaluru, Sudheer
    Gustavson, Daniel E.
    Hayward, Caroline
    Hofer, Edith
    Ikram, M. Arfan
    Karlsson, Robert
    Knowles, Emma
    Lahti, Jari
    Leber, Markus
    Li, Shuo
    Mather, Karen A.
    Melle, Ingrid
    Morris, Derek
    Oldmeadow, Christopher
    Palviainen, Teemu
    Payton, Antony
    Pazoki, Raha
    Petrovic, Katja
    Reynolds, Chandra A.
    Sargurupremraj, Muralidharan
    Scholz, Markus
    Smith, Jennifer A.
    Smith, Albert V.
    Terzikhan, Natalie
    Thalamuthu, Anbupalam
    Trompet, Stella
    van der Lee, Sven J.
    Ware, Erin B.
    Windham, B. Gwen
    Wright, Margaret J.
    Yang, Jingyun
    Yu, Jin
    Ames, David
    Amin, Najaf
    Amouyel, Philippe
    Andreassen, Ole A.
    Armstrong, Nicola J.
    Assareh, Amelia A.
    Attia, John R.
    Attix, Deborah
    Avramopoulos, Dimitrios
    Bennett, David A.
    Boehmer, Anne C.
    Boyle, Patricia A.
    Brodaty, Henry
    Campbell, Harry
    Cannon, Tyrone D.
    Cirulli, Elizabeth T.
    Congdon, Eliza
    Conley, Emily Drabant
    Corley, Janie
    Cox, Simon R.
    Dale, Anders M.
    Dehghan, Abbas
    Dick, Danielle
    Dickinson, Dwight
    Eriksson, Johan G.
    Evangelou, Evangelos
    Faul, Jessica D.
    Ford, Ian
    Freimer, Nelson A.
    Gao, He
    Giegling, Ina
    Gillespie, Nathan A.
    Gordon, Scott D.
    Gottesman, Rebecca F.
    Griswold, Michael E.
    Gudnason, Vilmundur
    Harris, Tamara B.
    Hartmann, Annette M.
    Hatzimanolis, Alex
    Heiss, Gerardo
    Holliday, Elizabeth G.
    Joshi, Peter K.
    Kahonen, Mika
    Kardia, Sharon L. R.
    Karlsson, Ida
    Kleineidam, Luca
    Knopman, David S.
    Kochan, Nicole A.
    Konte, Bettina
    Kwok, John B.
    Le Hellard, Stephanie
    Lee, Teresa
    Lehtimaki, Terho
    Li, Shu-Chen
    Liu, Tian
    Koini, Marisa
    London, Edythe
    Longstreth, Will T.
    Lopez, Oscar L.
    Loukola, Anu
    Luck, Tobias
    Lundervold, Astri J.
    Lundquist, Anders
    Lyytikainen, Leo-Pekka
    Martin, Nicholas G.
    Montgomery, Grant W.
    Murray, Alison D.
    Need, Anna C.
    Noordam, Raymond
    Nyberg, Lars
    Ollier, William
    Papenberg, Göran
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI). Max Planck Institute for Human Development, Germany.
    Pattie, Alison
    Polasek, Ozren
    Poldrack, Russell A.
    Psaty, Bruce M.
    Reppermund, Simone
    Riedel-Heller, Steffi G.
    Rose, Richard J.
    Rotter, Jerome I.
    Roussos, Panos
    Rovio, Suvi P.
    Saba, Yasaman
    Sabb, Fred W.
    Sachdev, Perminder S.
    Satizabal, Claudia L.
    Schmid, Matthias
    Scott, Rodney J.
    Scult, Matthew A.
    Simino, Jeannette
    Slagboom, P. Eline
    Smyrnis, Nikolaos
    Soumare, Aicha
    Stefanis, Nikos C.
    Stott, David J.
    Straub, Richard E.
    Sundet, Kjetil
    Taylor, Adele M.
    Taylor, Kent D.
    Tzoulaki, Ioanna
    Tzourio, Christophe
    Uitterlinden, Andre
    Vitart, Veronique
    Voineskos, Aristotle N.
    Kaprio, Jaakko
    Wagner, Michael
    Wagner, Holger
    Weinhold, Leonie
    Wen, K. Hoyan
    Widen, Elisabeth
    Yang, Qiong
    Zhao, Wei
    Adams, Hieab H. H.
    Arking, Dan E.
    Bilder, Robert M.
    Bitsios, Panos
    Boerwinkle, Eric
    Chiba-Falek, Ornit
    Corvin, Aiden
    De Jager, Philip L.
    Debette, Stephanie
    Donohoe, Gary
    Elliott, Paul
    Fitzpatrick, Annette L.
    Gill, Michael
    Glahn, David C.
    Hagg, Sara
    Hansell, Narelle K.
    Hariri, Ahmad R.
    Ikram, M. Kamran
    Jukema, J. Wouter
    Vuoksimaa, Eero
    Keller, Matthew C.
    Kremen, William S.
    Launer, Lenore
    Lindenberger, Ulman
    Palotie, Aarno
    Pedersen, Nancy L.
    Pendleton, Neil
    Porteous, David J.
    Raikkonen, Katri
    Raitakari, Olli T.
    Ramirez, Alfredo
    Reinvang, Ivar
    Rudan, Igor
    Rujescu, Dan
    Schmidt, Reinhold
    Schmidt, Helena
    Schofield, Peter W.
    Schofield, Peter R.
    Starr, John M.
    Steen, Vidar M.
    Trollor, Julian N.
    Turner, Steven T.
    Van Duijn, Cornelia M.
    Villringer, Arno
    Weinberger, Daniel R.
    Weir, David R.
    Wilson, James F.
    Malhotra, Anil
    McIntosh, Andrew M.
    Gale, Catharine R.
    Seshadri, Sudha
    Mosley, Thomas H.
    Bressler, Jan
    Lencz, Todd
    Deary, Ian J.
    Study of 300,486 individuals identifies 148 independent genetic loci influencing general cognitive function2018Inngår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 9, artikkel-id 2098Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    General cognitive function is a prominent and relatively stable human trait that is associated with many important life outcomes. We combine cognitive and genetic data from the CHARGE and COGENT consortia, and UK Biobank (total N = 300,486; age 16-102) and find 148 genome-wide significant independent loci (P < 5 x 10(-8)) associated with general cognitive function. Within the novel genetic loci are variants associated with neurodegenerative and neurodevelopmental disorders, physical and psychiatric illnesses, and brain structure. Gene-based analyses find 709 genes associated with general cognitive function. Expression levels across the cortex are associated with general cognitive function. Using polygenic scores, up to 4.3% of variance in general cognitive function is predicted in independent samples. We detect significant genetic overlap between general cognitive function, reaction time, and many health variables including eyesight, hypertension, and longevity. In conclusion we identify novel genetic loci and pathways contributing to the heritability of general cognitive function.

  • 40.
    de Gysser, Isabell
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för matematikämnets och naturvetenskapsämnenas didaktik.
    Språkstödjande undervisning i de naturorienterade ämnena: En studie i grundskolans år 4-6 utifrån lärares perspektiv på undervisning2016Student paper second term, 10 poäng / 15 hpOppgave
    Abstract [sv]

    Syftet med den här studien är att belysa och tillföra ämnesdidaktisk kunskap kring språkstödjande undervisning i de naturorienterade ämnena i grundskolans årskurser 4-6. Studien ställer upp tre forskningsfrågor som handlar om hur några lärare beskriver sin undervisning i de naturorienterade ämnena utifrån ett språkligt förhållningssätt, vilka praktiska tillvägagångssätt de väljer att använda samt hur dessa val syftar till att skapa förståelse för ämnesspecifikt innehåll hos eleverna. Studien har således ett perspektiv på undervisning utifrån en lärarhorisont och grundar sig på sex kvalitativa semistrukturerade lärarintervjuer. Insamlat material har analyserats och resulterat i fem teman som strukturerar informanternas utsagor om deras språkinriktade undervisning: mötet med ämnesspråket, svårigheter och signifikant svårare områden, metoder och aktiviteter, synlig kunskapsutveckling samt framgångsfaktorer. Studien visar i likhet med tidigare empirisk forskning kring det naturvetenskapliga språkets särdrag att det skolspråk eleverna möter i NO-undervisningen i årskurs 4-6 har komplexa beståndsdelar. Undervisningen handlar mycket om att stötta eleverna i den språkligt och innehållsligt abstrakta världen genom metoder och aktiviteter som kopplar nytt ämnesstoff till en för eleverna välkänd kontext. När lärarna beskriver didaktiska val handlar det i stor utsträckning om sådana som kontextualiserar ämnesinnehållet, gör eleverna delaktiga i kommunikativa sammanhang samt ställer upp ett stödjande ramverk kring språket. Utifrån studiens resultat och teoretiska bakgrund kan lärarstudenter, lärare, skolledare eller annan personal verksam i svensk skola finna belägg för vikten av att ställa upp kunskapsmål och språkliga mål. Diskussionen i studien leder fram till ett förslag på vidare studier som handlar om de, från tidigare forskning uppställda tre kännetecken för en funktionell språkinriktad undervisning; kontextualisering, interaktion samt språkstöttning, skulle kunna utökas till att även omfatta en aspekt som handlar om vikten av repetition i undervisningen. I den här studien blev denna fjärde aspekt framträdande tillsammans med de tre övriga. 

  • 41. de lavergne, C.
    et al.
    Madec, G.
    Roquet, Fabien
    Stockholms universitet, Naturvetenskapliga fakulteten, Meteorologiska institutionen (MISU).
    Holmes, R. M.
    McDougall, T. J.
    Abyssal ocean overturning shaped by seafloor distribution2017Inngår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 551, nr 7679, s. 181-186Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The abyssal ocean is broadly characterized by northward flow of the densest waters and southward flow of less-dense waters above them. Understanding what controls the strength and structure of these interhemispheric flows-referred to as the abyssal overturning circulation-is key to quantifying the ocean's ability to store carbon and heat on timescales exceeding a century. Here we show that, north of 32 degrees S, the depth distribution of the seafloor compels dense southernorigin waters to flow northward below a depth of about 4 kilometres and to return southward predominantly at depths greater than 2.5 kilometres. Unless ventilated from the north, the overlying mid-depths (1 to 2.5 kilometres deep) host comparatively weak mean meridional flow. Backed by analysis of historical radiocarbon measurements, the findings imply that the geometry of the Pacific, Indian and Atlantic basins places a major external constraint on the overturning structure.

  • 42. de Vries, Paul S.
    et al.
    Sabater-Lleal, Maria
    Chasman, Daniel I.
    Trompet, Stella
    Ahluwalia, Tarunveer S.
    Teumer, Alexander
    Kleber, Marcus E.
    Chen, Ming-Huei
    Wang, Jie Jin
    Attia, John R.
    Marioni, Riccardo E.
    Steri, Maristella
    Weng, Lu-Chen
    Pool, Rene
    Grossmann, Vera
    Brody, Jennifer A.
    Venturini, Cristina
    Tanaka, Toshiko
    Rose, Lynda M.
    Oldmeadow, Christopher
    Mazur, Johanna
    Basu, Saonli
    Frånberg, Mattias
    Stockholms universitet, Naturvetenskapliga fakulteten, Numerisk analys och datalogi (NADA). Karolinska Institutet, Sweden.
    Yang, Qiong
    Ligthart, Symen
    Hottenga, Jouke J.
    Rumley, Ann
    Mulas, Antonella
    de Craen, Anton J. M.
    Grotevendt, Anne
    Taylor, Kent D.
    Delgado, Graciela E.
    Kifley, Annette
    Lopez, Lorna M.
    Berentzen, Tina L.
    Mangino, Massimo
    Bandinelli, Stefania
    Morrison, Alanna C.
    Hamsten, Anders
    Tofler, Geoffrey
    de Maat, Moniek P. M.
    Draisma, Harmen H. M.
    Lowe, Gordon D.
    Zoledziewska, Magdalena
    Sattar, Naveed
    Lackner, Karl J.
    Voelker, Uwe
    McKnight, Barbara
    Huang, Jie
    Holliday, Elizabeth G.
    McEvoy, Mark A.
    Starr, John M.
    Hysi, Pirro G.
    Hernandez, Dena G.
    Guan, Weihua
    Rivadeneira, Fernando
    McArdle, Wendy L.
    Slagboom, P. Eline
    Zeller, Tanja
    Psaty, Bruce M.
    Uitterlinden, Andre G.
    de Geus, Eco J. C.
    Stott, David J.
    Binder, Harald
    Hofman, Albert
    Franco, Oscar H.
    Rotter, Jerome I.
    Ferrucci, Luigi
    Spector, Tim D.
    Deary, Ian J.
    Maerz, Winfried
    Greinacher, Andreas
    Wild, Philipp S.
    Cucca, Francesco
    Boomsma, Dorret I.
    Watkins, Hugh
    Tang, Weihong
    Ridker, Paul M.
    Jukema, Jan W.
    Scott, Rodney J.
    Mitchell, Paul
    Hansen, Torben
    O'Donnell, Christopher J.
    Smith, Nicholas L.
    Strachan, David P.
    Dehghan, Abbas
    Comparison of HapMap and 1000 Genomes Reference Panels in a Large-Scale Genome-Wide Association Study2017Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, nr 1, artikkel-id e0167742Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An increasing number of genome-wide association (GWA) studies are now using the higher resolution 1000 Genomes Project reference panel (1000G) for imputation, with the expectation that 1000G imputation will lead to the discovery of additional associated loci when compared to HapMap imputation. In order to assess the improvement of 1000G over HapMap imputation in identifying associated loci, we compared the results of GWA studies of circulating fibrinogen based on the two reference panels. Using both HapMap and 1000G imputation we performed a meta-analysis of 22 studies comprising the same 91,953 individuals. We identified six additional signals using 1000G imputation, while 29 loci were associated using both HapMap and 1000G imputation. One locus identified using HapMap imputation was not significant using 1000G imputation. The genome-wide significance threshold of 5x10(-8) is based on the number of independent statistical tests using HapMap imputation, and 1000G imputation may lead to further independent tests that should be corrected for. When using a stricter Bonferroni correction for the 1000G GWA study (P-value < 2.5x10(-8)), the number of loci significant only using HapMap imputation increased to 4 while the number of loci significant only using 1000G decreased to 5. In conclusion, 1000G imputation enabled the identification of 20% more loci than HapMap imputation, although the advantage of 1000G imputation became less clear when a stricter Bonferroni correction was used. More generally, our results provide insights that are applicable to the implementation of other dense reference panels that are under development.

  • 43. Del Giudice, Marco
    et al.
    Bosia, Carla
    Grigolon, Silvia
    Bo, Stefano
    Stockholms universitet, Nordiska institutet för teoretisk fysik (Nordita).
    Stochastic sequestration dynamics: a minimal model with extrinsic noise for bimodal distributions and competitors correlation2018Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, artikkel-id 10387Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Many biological processes are known to be based on molecular sequestration. This kind of dynamics involves two types of molecular species, namely targets and sequestrants, that bind to form a complex. In the simple framework of mass-action law, key features of these systems appear to be threshold-like profiles of the amounts of free molecules as a function of the parameters determining their possible maximum abundance. However, biochemical processes are probabilistic and take place in stochastically fluctuating environments. How these different sources of noise affect the final outcome of the network is not completely characterised yet. In this paper we specifically investigate the effects induced by a source of extrinsic noise onto a minimal stochastic model of molecular sequestration. We analytically show how bimodal distributions of the targets can appear and characterise them as a result of noise filtering mediated by the threshold response. We then address the correlations between target species induced by the sequestrant and discuss how extrinsic noise can turn the negative correlation caused by competition into a positive one. Finally, we consider the more complex scenario of competitive inhibition for enzymatic kinetics and discuss the relevance of our findings with respect to applications.

  • 44. Dellantonio, Luca
    et al.
    Kyriienko, Oleksandr
    Stockholms universitet, Nordiska institutet för teoretisk fysik (Nordita). University of Copenhagen, Denmark.
    Marquardt, Florian
    Sørensen, Anders S.
    Quantum nondemolition measurement of mechanical motion quanta2018Inngår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 9, artikkel-id 3621Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The fields of optomechanics and electromechanics have facilitated numerous advances in the areas of precision measurement and sensing, ultimately driving the studies of mechanical systems into the quantum regime. To date, however, the quantization of the mechanical motion and the associated quantum jumps between phonon states remains elusive. For optomechanical systems, the coupling to the environment was shown to make the detection of the mechanical mode occupation difficult, typically requiring the single-photon strong coupling regime. Here, we propose and analyse an electromechanical setup, which allows us to overcome this limitation and resolve the energy levels of a mechanical oscillator. We found that the heating of the membrane, caused by the interaction with the environment and unwanted couplings, can be suppressed for carefully designed electromechanical systems. The results suggest that phonon number measurement is within reach for modern electromechanical setups.

  • 45. Didion, John P.
    et al.
    Martin, Marcel
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Collins, Francis S.
    Atropos: specific, sensitive, and speedy trimming of sequencing reads2017Inngår i: PeerJ, ISSN 2167-8359, E-ISSN 2167-8359, Vol. 5, artikkel-id e3720Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A key step in the transformation of raw sequencing reads into biological insights is the trimming of adapter sequences and low-quality bases. Read trimming has been shown to increase the quality and reliability while decreasing the computational requirements of downstream analyses. Many read trimming software tools are available; however, no tool simultaneously provides the accuracy, computational efficiency, and feature set required to handle the types and volumes of data generated in modern sequencing-based experiments. Here we introduce Atropos and show that it trims reads with high sensitivity and specificity while maintaining leadingedge speed. Compared to other state-of-the-art read trimming tools, Atropos achieves significant increases in trimming accuracy while remaining competitive in execution times. Furthermore, Atropos maintains high accuracy even when trimming data with elevated rates of sequencing errors. The accuracy, high performance, and broad feature set offered by Atropos makes it an appropriate choice for the pre-processing of Illumina, ABI SOLiD, and other current-generation short-read sequencing datasets. Atropos is open source and free software written in Python (3.3+) and available at https://github. com/jdidion/atropos.

  • 46.
    Dreijer, Sara
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholm Resilience Centre.
    The complex evolution of Japan's distant water fisheries: Exploring the evolution of Japan's distant water fisheries from 1950-20142018Independent thesis Advanced level (degree of Master (Two Years)), 40 poäng / 60 hpOppgave
    Abstract [en]

    Fisheries are dynamic social-ecological systems shaped by the interplay of diverse political, economic, social and ecological factors. Recently, recognition has grown that fisheries are complex adaptive systems and warrant examination within a broader social-ecological context. While there has been a recent trend within fisheries science and management towards embracing more holistic approaches, research on global fisheries rarely addresses the complexities that shape large-scale fishing patterns. In this thesis I adopt a complex systems perspective with the ambition of understanding the complex and context-specific nature of global fishing by exploring the evolution of the Japanese distant water fishery (DWF). By combining investigation of global catch statistics with a review of associated primary, secondary and grey literature, I produce a narrative of how the Japanese DWF has expanded and contracted between 1950 and 2014, its geographical extent, and the factors that have contributed to these patterns. The results illustrate how complex and context-specific the DWF system is in the case of Japan. Using this in-depth study, I then address recent publications on global fisheries that use approaches that tend to minimise complexity through generalisations rather than seeking a deeper understanding of how this complexity shapes global fisheries. Finally, based on the exploratory findings of this thesis, I suggest that to better understand the complex dynamics inherent to global fisheries, further research informed by complexity thinking is needed on distant water fishing nations.

  • 47.
    Díez, Beatriz
    et al.
    Stockholms universitet, Science for Life Laboratory (SciLifeLab). Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik. Pontificia Universidad Católica de Chile, Chile; Center for Climate Change and Resilience Research (CR)2, Chile.
    Nylander, Johan A. A.
    Stockholms universitet, Science for Life Laboratory (SciLifeLab). Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik. Swedish Museum of Natural History, Sweden.
    Ininbergs, Karolina
    Stockholms universitet, Science for Life Laboratory (SciLifeLab). Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Dupont, Christopher L.
    Allen, Andrew E.
    Yooseph, Shibu
    Rusch, Douglas B.
    Bergman, Birgitta
    Stockholms universitet, Science for Life Laboratory (SciLifeLab). Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Metagenomic Analysis of the Indian Ocean Picocyanobacterial Community: Structure, Potential Function and Evolution2016Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, nr 5, artikkel-id e0155757Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Unicellular cyanobacteria are ubiquitous photoautotrophic microbes that contribute substantially to global primary production. Picocyanobacteria such as Synechococcus and Prochlorococcus depend on chlorophyll a-binding protein complexes to capture light energy. In addition, Synechococcus has accessory pigments organized into phycobilisomes, and Prochlorococcus contains chlorophyll b. Across a surface water transect spanning the sparsely studied tropical Indian Ocean, we examined Synechococcus and Prochlorococcus occurrence, taxonomy and habitat preference in an evolutionary context. Shotgun sequencing of size fractionated microbial communities from 0.1 mu m to 20 mu m and subsequent phylogenetic analysis indicated that cyanobacteria account for up to 15% of annotated reads, with the genera Prochlorococcus and Synechococcus comprising 90% of the cyanobacterial reads, even in the largest size fraction (3.0-20 mm). Phylogenetic analyses of cyanobacterial lightharvesting genes (chl-binding pcb/isiA, allophycocyanin (apcAB), phycocyanin (cpcAB) and phycoerythin (cpeAB)) mostly identified picocyanobacteria clades comprised of overlapping sequences obtained from Indian Ocean, Atlantic and/or Pacific Oceans samples. Habitat reconstructions coupled with phylogenetic analysis of the Indian Ocean samples suggested that large Synechococcus-like ancestors in coastal waters expanded their ecological niche towards open oligotrophic waters in the Indian Ocean through lineage diversification and associated streamlining of genomes (e.g. loss of phycobilisomes and acquisition of Chl b); resulting in contemporary small celled Prochlorococcus. Comparative metagenomic analysis with picocyanobacteria populations in other oceans suggests that this evolutionary scenario may be globally important.

  • 48.
    Ebert, Karin
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi.
    Axelsson, Leona
    Harbor, Jon
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi. Purdue University, USA.
    Opportunities and challenges for building alumni networks in Sweden: a case study of Stockholm University2015Inngår i: Journal of Higher Education Policy and Management, ISSN 1360-080X, E-ISSN 1469-9508, Vol. 37, nr 2, s. 252-262Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Because of the potential value of alumni involvement for student success, for connections to society and as a base for future philanthropy, there is growing interest in developing university alumni relations programmes in countries that do not have a long tradition in this area. This case study of Stockholm University describes the goals, strategies, barriers and successes of building an alumni programme in an environment that lacks a tradition of alumni relations and aims to provide perspectives and ideas that can help other universities worldwide with their work towards building alumni programmes that fit their cultural contexts and goals.

  • 49. Ericsson, Malin
    et al.
    Lundholm, Cecilia
    Fors, Stefan
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Centrum för forskning om äldre och åldrande (ARC), (tills m KI).
    Dahl Aslan, Anna K.
    Zavala, Catalina
    Reynolds, Chandra A.
    Pedersen, Nancy L.
    Childhood social class and cognitive aging in the Swedish Adoption/Twin Study of Aging2017Inngår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 114, nr 27, s. 7001-7006Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this report we analyzed genetically informative data to investigate within-person change and between-person differences in late-life cognitive abilities as a function of childhood social class. We used data from nine testing occasions spanning 28 y in the Swedish Adoption/Twin Study of Aging and parental social class based on the Swedish socioeconomic index. Cognitive ability included a general factor and the four domains of verbal, fluid, memory, and perceptual speed. Latent growth curve models of the longitudinal data tested whether level and change in cognitive performance differed as a function of childhood social class. Between-within twin-pair analyses were performed on twins reared apart to assess familial confounding. Childhood social class was significantly associated with mean-level cognitive performance at age 65 y, but not with rate of cognitive change. The association decreased in magnitude but remained significant after adjustments for level of education and the degree to which the rearing family was supportive toward education. A between-pair effect of childhood social class was significant in all cognitive domains, whereas within-pair estimates were attenuated, indicating genetic confounding. Thus, childhood social class is important for cognitive performance in adulthood on a population level, but the association is largely attributable to genetic influences.

  • 50.
    Eriksson, Helena
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för matematikämnets och naturvetenskapsämnenas didaktik. Dalarna University, Sweden.
    Identifying algebraic reasoning about fractions2018Inngår i: Proceedings of the 42nd Conference of the International Group for the Psychology of Mathematics Education / [ed] Ewa Bergqvist, Magnus Österholm, Carina Granberg, Lovisa Sumpter, Umeå, Sweden: PME , 2018, Vol. 1, s. 255-262Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The issue for this paper is to identify algebraic reasoning through students´sense-making actions, during a lesson, where students and a teacher develop learning models for mixed numbers. The analysis focuses the students’ work, trying to make sense of the unknown fractional part of the number. This unknown part was elaborated when the students suggested to “add a little bit more” to construct equality. The un-known part developed to a fractional part with help of an emerging learning model containing algebraic symbols: B=W+p/a. In this activity. The potentialities in the students’ algebraic reasoning were identifyed as: an additive relationship between the integer and the fractional part of the number, and a multiplicative relationship between the numerator and the denominator in this fractional part.

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