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Sökning: WFRF:(Hildebrand F.)

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1.
  • Correa, D. F., et al. (författare)
  • Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates
  • 2023
  • Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 32:1, s. 49-69
  • Tidskriftsartikel (refereegranskat)abstract
    • Aim To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period Tree-inventory plots established between 1934 and 2019. Major taxa studied Trees with a diameter at breast height (DBH) >= 9.55 cm. Location Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types.
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2.
  • Acciari, V. A., et al. (författare)
  • Radio Imaging of the Very-High-Energy gamma-Ray Emission Region in the Central Engine of a Radio Galaxy
  • 2009
  • Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 325:5939, s. 444-448
  • Tidskriftsartikel (refereegranskat)abstract
    • The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 10(12) electron volts and are bright sources of very-high-energy (VHE) gamma-ray emission, it is not yet known where the VHE emission originates. Here we report on radio and VHE observations of the radio galaxy Messier 87, revealing a period of extremely strong VHE gamma-ray flares accompanied by a strong increase of the radio flux from its nucleus. These results imply that charged particles are accelerated to very high energies in the immediate vicinity of the black hole.
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3.
  • Abramowski, A., et al. (författare)
  • The 2010 very high energy gamma-RAY flare and 10 years of multi-wavelength observations of M 87
  • 2012
  • Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 746:2, s. 151-
  • Tidskriftsartikel (refereegranskat)abstract
    • The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3-6) x 10(9) M-circle dot) provides a unique opportunity to investigate the origin of very high energy (VHE; E > 100 GeV) gamma-ray emission generated in relativistic outflows and the surroundings of supermassive black holes. M 87 has been established as a VHE gamma-ray emitter since 2006. The VHE gamma-ray emission displays strong variability on timescales as short as a day. In this paper, results from a joint VHE monitoring campaign on M 87 by the MAGIC and VERITAS instruments in 2010 are reported. During the campaign, a flare at VHE was detected triggering further observations at VHE (H.E.S.S.), X-rays (Chandra), and radio (43 GHz Very Long Baseline Array, VLBA). The excellent sampling of the VHE gamma-ray light curve enables one to derive a precise temporal characterization of the flare: the single, isolated flare is well described by a two-sided exponential function with significantly different flux rise and decay times of tau(rise)(d) = (1.69 +/- 0.30) days and tau(decay)(d) = (0.611 +/- 0.080) days, respectively. While the overall variability pattern of the 2010 flare appears somewhat different from that of previous VHE flares in 2005 and 2008, they share very similar timescales (similar to day), peak fluxes (Phi(>0.35 TeV) similar or equal to (1-3) x 10(-11) photons cm(-2) s(-1)), and VHE spectra. VLBA radio observations of 43 GHz of the inner jet regions indicate no enhanced flux in 2010 in contrast to observations in 2008, where an increase of the radio flux of the innermost core regions coincided with a VHE flare. On the other hand, Chandra X-ray observations taken similar to 3 days after the peak of the VHE gamma-ray emission reveal an enhanced flux from the core (flux increased by factor similar to 2; variability timescale <2 days). The long-term (2001-2010) multi-wavelength (MWL) light curve of M 87, spanning from radio to VHE and including data from Hubble Space Telescope, Liverpool Telescope, Very Large Array, and European VLBI Network, is used to further investigate the origin of the VHE gamma-ray emission. No unique, common MWL signature of the three VHE flares has been identified. In the outer kiloparsec jet region, in particular in HST-1, no enhanced MWL activity was detected in 2008 and 2010, disfavoring it as the origin of the VHE flares during these years. Shortly after two of the three flares (2008 and 2010), the X-ray core was observed to be at a higher flux level than its characteristic range (determined from more than 60 monitoring observations: 2002-2009). In 2005, the strong flux dominance of HST-1 could have suppressed the detection of such a feature. Published models for VHE gamma-ray emission from M 87 are reviewed in the light of the new data.
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4.
  • Aleksic, J., et al. (författare)
  • DETECTION OF VERY HIGH ENERGY gamma-RAY EMISSION FROM THE PERSEUS CLUSTER HEAD-TAIL GALAXY IC 310 BY THE MAGIC TELESCOPES
  • 2010
  • Ingår i: The Astrophysical Journal Letters. - 2041-8205. ; 723:2, s. l207-L212
  • Tidskriftsartikel (refereegranskat)abstract
    • We report on the detection with the MAGIC telescopes of very high energy (VHE) gamma-rays from IC 310, a head-tail radio galaxy in the Perseus galaxy cluster, observed during the interval 2008 November to 2010 February. The Fermi satellite has also detected this galaxy. The source is detected by MAGIC at a high statistical significance of 7.6 sigma in 20.6 hr of stereo data. The observed spectral energy distribution is flat with a differential spectral index of -2.00 +/- 0.14. The mean flux above 300 GeV, between 2009 October and 2010 February, (3.1 +/- 0.5) x 10(-12) cm(-2) s(-1), corresponds to (2.5 +/- 0.4)% of Crab Nebula units. Only an upper limit, of 1.9% of Crab Nebula units above 300 GeV, was obtained with the 2008 data. This, together with strong hints (>3 sigma) of flares in the middle of 2009 October and November, implies that the emission is variable. The MAGIC results favor a scenario with the VHE emission originating from the inner jet close to the central engine. More complicated models than a simple one-zone synchrotron self-Compton (SSC) scenario, e. g., multi-zone SSC, external Compton, or hadronic, may be required to explain the very flat spectrum and its extension over more than three orders of magnitude in energy.
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5.
  • Aleksic, J., et al. (författare)
  • PG 1553+113 : FIVE YEARS OF OBSERVATIONS WITH MAGIC
  • 2012
  • Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 748:1, s. 46-
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the results of five years (2005-2009) of MAGIC observations of the BL Lac object PG 1553+113 at very high energies (VHEs; E > 100 GeV). Power-law fits of the individual years are compatible with a steady mean photon index Gamma = 4.27 +/- 0.14. In the last three years of data, the flux level above 150 GeV shows a clear variability (probability of constant flux < 0.001%). The flux variations are modest, lying in the range from 4% to 11% of the Crab Nebula flux. Simultaneous optical data also show only modest variability that seems to be correlated with VHE gamma-ray variability. We also performed a temporal analysis of (all available) simultaneous Fermi/Large Area Telescope data of PG 1553+113 above 1 GeV, which reveals hints of variability in the 2008-2009 sample. Finally, we present a combination of the mean spectrum measured at VHEs with archival data available for other wavelengths. The mean spectral energy distribution can be modeled with a one-zone synchrotron self-Compton model, which gives the main physical parameters governing the VHE emission in the blazar jet.
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6.
  • Aleksic, J., et al. (författare)
  • Discovery of VHE gamma-rays from the blazar 1ES 1215+303 with the MAGIC telescopes and simultaneous multi-wavelength observations
  • 2012
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 544, s. A142-
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. We present the discovery of very high energy (VHE, E > 100 GeV) gamma-ray emission from the BL Lac object 1ES 1215+303 by the MAGIC telescopes and simultaneous multi-wavelength data in a broad energy range from radio to gamma-rays. Aims. We study the VHE gamma-ray emission from 1ES 1215+303 and its relation to the emissions in other wavelengths. Methods. Triggered by an optical outburst, MAGIC observed the source in 2011 January-February for 20.3 h. The target was monitored in the optical R-band by the KVA telescope that also performed optical polarization measurements. We triggered target of opportunity observations with the Swift satellite and obtained simultaneous and quasi-simultaneous data from the Fermi Large Area Telescope and from the Metsahovi radio telescope. We also present the analysis of older MAGIC data taken in 2010. Results. The MAGIC observations of 1ES 1215+303 carried out in 2011 January-February resulted in the first detection of the source at VHE with a statistical significance of 9.4 sigma. Simultaneously, the source was observed in a high optical and X-ray state. In 2010 the source was observed in a lower state in optical, X-ray, and VHE, while the GeV gamma-ray flux and the radio flux were comparable in 2010 and 2011. The spectral energy distribution obtained with the 2011 data can be modeled with a simple one zone SSC model, but it requires extreme values for the Doppler factor or the electron energy distribution.
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7.
  • Aleksic, J., et al. (författare)
  • MAGIC reveals a complex morphology within the unidentified gamma-ray source HESS J1857+026
  • 2014
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 571
  • Tidskriftsartikel (refereegranskat)abstract
    • Aims. HESS J1857+026 is an extended TeV gamma-ray source that was discovered by H. E. S. S. as part of its Galactic plane survey. Given its broadband spectral energy distribution and its spatial coincidence with the young energetic pulsar PSR J1856+0245, the source has been put forward as a pulsar wind nebula (PWN) candidate. MAGIC has performed follow-up observations aimed at mapping the source down to energies approaching 100 GeV in order to better understand its complex morphology. Methods. HESS J1857+026 was observed by MAGIC in 2010, yielding 29 h of good quality stereoscopic data that allowed us to map the source region in two separate ranges of energy. Results. We detected very-high-energy gamma-ray emission from HESS J1857+026 with a significance of 12 sigma above 150 GeV. The differential energy spectrum between 100 GeV and 13 TeV is described well by a power law function dN/dE = N-0(E/1TeV)(-Gamma) with N-0 = (5.37 +/- 0.44(stat) +/- 1.5(sys)) X 10(-12) (TeV-1 cm(-2) s(-1)) and Gamma = 2.16 +/- 0.07(stat) +/- 0.15(sys), which bridges the gap between the GeV emission measured by Fermi-LAT and the multi-TeV emission measured by H.E.S.S.. In addition, we present a detailed analysis of the energy-dependent morphology of this region. We couple these results with archival multiwavelength data and outline evidence in favor of a two-source scenario, whereby one source is associated with a PWN, while the other could be linked with a molecular cloud complex containing an HII region and a possible gas cavity.
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8.
  • Householder, John Ethan, et al. (författare)
  • One sixth of Amazonian tree diversity is dependent on river floodplains
  • 2024
  • Ingår i: NATURE ECOLOGY & EVOLUTION. - 2397-334X.
  • Tidskriftsartikel (refereegranskat)abstract
    • Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.
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9.
  • Aleksic, J., et al. (författare)
  • Measurement of the Crab Nebula spectrum over three decades in energy with the MAGIC telescopes
  • 2015
  • Ingår i: Journal of High Energy Astrophysics. - : Elsevier BV. - 2214-4048 .- 2214-4056. ; 5-6, s. 30-38
  • Tidskriftsartikel (refereegranskat)abstract
    • The MAGIC stereoscopic system collected 69 hours of Crab Nebula data between October 2009 and April 2011. Analysis of this data sample using the latest improvements in the MAGIC stereoscopic software provided an unprecedented precision of spectral and night-by-night light curve determination at gamma rays. We derived a differential spectrum with a single instrument from 50 GeV up to almost 30 TeV with 5 bins per energy decade. At low energies, MAGIC results, combined with Fermi-LAT data, show a flat and broad Inverse Compton peak. The overall fit to the data between 1 GeV and 30 TeV is not well described by a log-parabola function. We find that a modified log-parabola function with an exponent of 2.5 instead of 2 provides a good description of the data (chi(2)(red) = 35/26). Using systematic uncertainties of the MAGIC and Fermi-LAT measurements we determine the position of the Inverse Compton peak to be at (53 +/- 3(stat)+ 31(syst)-13(syst)) GeV, which is the most precise estimation up to date and is dominated by the systematic effects. There is no hint of the integral flux variability on daily scales at energies above 300 GeV when systematic uncertainties are included in the flux measurement. We consider three state-of-the-art theoretical models to describe the overall spectral energy distribution of the Crab Nebula. The constant B-field model cannot satisfactorily reproduce the VHE spectral measurements presented in this work, having particular difficulty reproducing the broadness of the observed IC peak. Most probably this implies that the assumption of the homogeneity of the magnetic field inside the nebula is incorrect. On the other hand, the time-dependent 1D spectral model provides a good fit of the new VHE results when considering a 80 mu G magnetic field. However, it fails to match the data when including the morphology of the nebula at lower wavelengths.
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10.
  • Luize, Bruno Garcia, et al. (författare)
  • Geography and ecology shape the phylogenetic composition of Amazonian tree communities
  • 2024
  • Ingår i: JOURNAL OF BIOGEOGRAPHY. - 0305-0270 .- 1365-2699.
  • Tidskriftsartikel (refereegranskat)abstract
    • Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and v & aacute;rzea forest types, the phylogenetic composition varies by geographic region, but the igap & oacute; and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R-2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R-2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions.
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11.
  • ter Steege, Hans, et al. (författare)
  • Mapping density, diversity and species-richness of the Amazon tree flora
  • 2023
  • Ingår i: COMMUNICATIONS BIOLOGY. - 2399-3642. ; 6:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution. A study mapping the tree species richness in Amazonian forests shows that soil type exerts a strong effect on species richness, probably caused by the areas of these forest types. Cumulative water deficit, tree density and temperature seasonality affect species richness at a regional scale.
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12.
  • Garcia-Garcia, A, et al. (författare)
  • Humans with inherited MyD88 and IRAK-4 deficiencies are predisposed to hypoxemic COVID-19 pneumonia
  • 2023
  • Ingår i: The Journal of experimental medicine. - : Rockefeller University Press. - 1540-9538 .- 0022-1007. ; 220:5
  • Tidskriftsartikel (refereegranskat)abstract
    • X-linked recessive deficiency of TLR7, a MyD88- and IRAK-4–dependent endosomal ssRNA sensor, impairs SARS-CoV-2 recognition and type I IFN production in plasmacytoid dendritic cells (pDCs), thereby underlying hypoxemic COVID-19 pneumonia with high penetrance. We report 22 unvaccinated patients with autosomal recessive MyD88 or IRAK-4 deficiency infected with SARS-CoV-2 (mean age: 10.9 yr; 2 mo to 24 yr), originating from 17 kindreds from eight countries on three continents. 16 patients were hospitalized: six with moderate, four with severe, and six with critical pneumonia, one of whom died. The risk of hypoxemic pneumonia increased with age. The risk of invasive mechanical ventilation was also much greater than in age-matched controls from the general population (OR: 74.7, 95% CI: 26.8–207.8, P &lt; 0.001). The patients’ susceptibility to SARS-CoV-2 can be attributed to impaired TLR7-dependent type I IFN production by pDCs, which do not sense SARS-CoV-2 correctly. Patients with inherited MyD88 or IRAK-4 deficiency were long thought to be selectively vulnerable to pyogenic bacteria, but also have a high risk of hypoxemic COVID-19 pneumonia.
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14.
  • Blideanu, V., et al. (författare)
  • Nucleon-induced reactions at intermediate energies : New data at 96 MeV and theoretical status
  • 2004
  • Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 70:1, s. 014607-
  • Tidskriftsartikel (refereegranskat)abstract
    • Double-differential cross sections for light charged particle production (up to A=4) were measured in 96 MeV neutron-induced reactions, at the TSL Laboratory Cyclotron in Uppsala (Sweden). Measurements for three targets, Fe, Pb, and U, were performed using two independent devices, SCANDAL and MEDLEY. The data were recorded with low-energy thresholds and for a wide angular range (20°–160°). The normalization procedure used to extract the cross sections is based on the np elastic scattering reaction that we measured and for which we present experimental results. A good control of the systematic uncertainties affecting the results is achieved. Calculations using the exciton model are reported. Two different theoretical approaches proposed to improve its predictive power regarding the complex particle emission are tested. The capabilities of each approach is illustrated by comparison with the 96 MeV data that we measured, and with other experimental results available in the literature.
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15.
  • Costea, P. I., et al. (författare)
  • Enterotypes in the landscape of gut microbial community composition
  • 2018
  • Ingår i: Nature Microbiology. - : Springer Science and Business Media LLC. - 2058-5276. ; 3:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Population stratification is a useful approach for a better understanding of complex biological problems in human health and wellbeing. The proposal that such stratification applies to the human gut microbiome, in the form of distinct community composition types termed enterotypes, has been met with both excitement and controversy. In view of accumulated data and re-analyses since the original work, we revisit the concept of enterotypes, discuss different methods of dividing up the landscape of possible microbiome configurations, and put these concepts into functional, ecological and medical contexts. As enterotypes are of use in describing the gut microbial community landscape and may become relevant in clinical practice, we aim to reconcile differing views and encourage a balanced application of the concept.
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17.
  • Hildebrand, Angelica, et al. (författare)
  • Elastic Neutron Scattering at 96 MeV
  • 2004
  • Ingår i: Proc. Int. Conf. on Nuclear Data for Science and Technology.
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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18.
  • Hildebrand, A, et al. (författare)
  • Elastic neutron scattering at 96 MeV
  • 2005
  • Ingår i: Proc. of the Int. Conf. on Nuclear Data for Science and Technology: Santa Fé, New Mexico, USA, September 26-October 1, 2004. ; , s. 853-
  • Konferensbidrag (refereegranskat)
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22.
  • Skotte, Line, et al. (författare)
  • Genome-wide association study of febrile seizures implicates fever response and neuronal excitability genes
  • 2022
  • Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 145:2, s. 555-568
  • Tidskriftsartikel (refereegranskat)abstract
    • Febrile seizures represent the most common type of pathological brain activity in young children and are influenced by genetic, environmental and developmental factors. In a minority of cases, febrile seizures precede later development of epilepsy. We conducted a genome-wide association study of febrile seizures in 7635 cases and 83 966 controls identifying and replicating seven new loci, all with P < 5 × 10-10. Variants at two loci were functionally related to altered expression of the fever response genes PTGER3 and IL10, and four other loci harboured genes (BSN, ERC2, GABRG2, HERC1) influencing neuronal excitability by regulating neurotransmitter release and binding, vesicular transport or membrane trafficking at the synapse. Four previously reported loci (SCN1A, SCN2A, ANO3 and 12q21.33) were all confirmed. Collectively, the seven novel and four previously reported loci explained 2.8% of the variance in liability to febrile seizures, and the single nucleotide polymorphism heritability based on all common autosomal single nucleotide polymorphisms was 10.8%. GABRG2, SCN1A and SCN2A are well-established epilepsy genes and, overall, we found positive genetic correlations with epilepsies (rg = 0.39, P = 1.68 × 10-4). Further, we found that higher polygenic risk scores for febrile seizures were associated with epilepsy and with history of hospital admission for febrile seizures. Finally, we found that polygenic risk of febrile seizures was lower in febrile seizure patients with neuropsychiatric disease compared to febrile seizure patients in a general population sample. In conclusion, this largest genetic investigation of febrile seizures to date implicates central fever response genes as well as genes affecting neuronal excitability, including several known epilepsy genes. Further functional and genetic studies based on these findings will provide important insights into the complex pathophysiological processes of seizures with and without fever.
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23.
  • Bedarf, J. R., et al. (författare)
  • Functional implications of microbial and viral gut metagenome changes in early stage L-DOPA-naive Parkinson's disease patients
  • 2017
  • Ingår i: Genome Medicine. - : Springer Science and Business Media LLC. - 1756-994X. ; 9
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Parkinson's disease (PD) presently is conceptualized as a protein aggregation disease in which pathology involves both the enteric and the central nervous system, possibly spreading from one to another via the vagus nerves. As gastrointestinal dysfunction often precedes or parallels motor symptoms, the enteric system with its vast diversity of microorganisms may be involved in PD pathogenesis. Alterations in the enteric microbial taxonomic level of L-DOPA-naive PD patients might also serve as a biomarker.Methods: We performed metagenomic shotgun analyses and compared the fecal microbiomes of 31 early stage, L-DOPA-naive PD patients to 28 age-matched controls.Results: We found increased Verrucomicrobiaceae (Akkermansia muciniphila) and unclassified Firmicutes, whereas Prevotellaceae (Prevotella copri) and Erysipelotrichaceae (Eubacterium biforme) were markedly lowered in PD samples. The observed differences could reliably separate PD from control with a ROC-AUC of 0.84. Functional analyses of the metagenomes revealed differences in microbiota metabolism in PD involving the beta-glucuronate and tryptophan metabolism. While the abundances of prophages and plasmids did not differ between PD and controls, total virus abundance was decreased in PD participants. Based on our analyses, the intake of either a MAO inhibitor, amantadine, or a dopamine agonist (which in summary relates to 90% of PD patients) had no overall influence on taxa abundance or microbial functions.Conclusions: Our data revealed differences of colonic microbiota and of microbiota metabolism between PD patients and controls at an unprecedented detail not achievable through 16S sequencing. The findings point to a yet unappreciated aspect of PD, possibly involving the intestinal barrier function and immune function in PD patients. The influence of the parkinsonian medication should be further investigated in the future in larger cohorts.
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25.
  • Bahram, Mohammad, et al. (författare)
  • Structure and function of the global topsoil microbiome
  • 2018
  • Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 560:7717, s. 233-7
  • Tidskriftsartikel (refereegranskat)abstract
    • Soils harbour some of the most diverse microbiomes on Earth and are essential for both nutrient cycling and carbon storage. To understand soil functioning, it is necessary to model the global distribution patterns and functional gene repertoires of soil microorganisms, as well as the biotic and environmental associations between the diversity and structure of both bacterial and fungal soil communities(1-4). Here we show, by leveraging metagenomics and metabarcoding of global topsoil samples (189 sites, 7,560 subsamples), that bacterial, but not fungal, genetic diversity is highest in temperate habitats and that microbial gene composition varies more strongly with environmental variables than with geographic distance. We demonstrate that fungi and bacteria show global niche differentiation that is associated with contrasting diversity responses to precipitation and soil pH. Furthermore, we provide evidence for strong bacterial-fungal antagonism, inferred from antibiotic-resistance genes, in topsoil and ocean habitats, indicating the substantial role of biotic interactions in shaping microbial communities. Our results suggest that both competition and environmental filtering affect the abundance, composition and encoded gene functions of bacterial and fungal communities, indicating that the relative contributions of these microorganisms to global nutrient cycling varies spatially.
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  • Forssten, Maximilian Peter, 1996-, et al. (författare)
  • Adverse outcomes following pelvic fracture : the critical role of frailty
  • 2023
  • Ingår i: European Journal of Trauma and Emergency Surgery. - : Urban und Vogel Medien und Medizin Verlagsgesellsc. - 1863-9933 .- 1863-9941. ; 49:6, s. 2623-2631
  • Tidskriftsartikel (refereegranskat)abstract
    • PURPOSE: Pelvic fractures among older adults are associated with an increased risk of adverse outcomes, with frailty likely being a contributing factor. The current study endeavors to describe the association between frailty, measured using the Orthopedic Frailty Score (OFS), and adverse outcomes in geriatric pelvic fracture patients.METHODS: All geriatric (65 years or older) patients registered in the 2013-2019 Trauma Quality Improvement Program database with an isolated pelvic fracture following blunt trauma were considered for inclusion. An isolated pelvic fracture was defined as any fracture in the pelvis with a lower extremity AIS ≥ 2, any abdomen AIS, and an AIS ≤ 1 in all other regions. Poisson regression models were employed to determine the association between the OFS and adverse outcomes.RESULTS: A total of 66,404 patients were included for further analysis. 52% (N = 34,292) were classified as non-frail (OFS 0), 32% (N = 21,467) were pre-frail (OFS 1), and 16% (N = 10,645) were classified as frail (OFS ≥ 2). Compared to non-frail patients, frail patients exhibited a 88% increased risk of in-hospital mortality [adjusted IRR (95% CI): 1.88 (1.54-2.30), p < 0.001], a 25% increased risk of complications [adjusted IRR (95% CI): 1.25 (1.10-1.42), p < 0.001], a 56% increased risk of failure-to-rescue [adjusted IRR (95% CI): 1.56 (1.14-2.14), p = 0.006], and a 10% increased risk of ICU admission [adjusted IRR (95% CI): 1.10 (1.02-1.18), p = 0.014].CONCLUSION: Frail pelvic fracture patients suffer from a disproportionately increased risk of mortality, complications, failure-to-rescue, and ICU admission. Additional measures are required to mitigate adverse events in this vulnerable patient population.
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28.
  • HILDEBRAND, C, et al. (författare)
  • Teeth and tooth nerves
  • 1995
  • Ingår i: Progress in neurobiology. - 0301-0082. ; 45:3, s. 165-222
  • Tidskriftsartikel (refereegranskat)
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29.
  • Hildebrand, S, et al. (författare)
  • The E-cadherin/AmotL2 complex organizes actin filaments required for epithelial hexagonal packing and blastocyst hatching
  • 2017
  • Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1, s. 9540-
  • Tidskriftsartikel (refereegranskat)abstract
    • Epithelial cells connect via cell-cell junctions to form sheets of cells with separate cellular compartments. These cellular connections are essential for the generation of cellular forms and shapes consistent with organ function. Tissue modulation is dependent on the fine-tuning of mechanical forces that are transmitted in part through the actin connection to E-cadherin as well as other components in the adherens junctions. In this report we show that p100 amotL2 forms a complex with E-cadherin that associates with radial actin filaments connecting cells over multiple layers. Genetic inactivation or depletion of amotL2 in epithelial cells in vitro or zebrafish and mouse in vivo, resulted in the loss of contractile actin filaments and perturbed epithelial packing geometry. We further showed that AMOTL2 mRNA and protein was expressed in the trophectoderm of human and mouse blastocysts. Genetic inactivation of amotL2 did not affect cellular differentiation but blocked hatching of the blastocysts from the zona pellucida. These results were mimicked by treatment with the myosin II inhibitor blebbistatin. We propose that the tension generated by the E-cadherin/AmotL2/actin filaments plays a crucial role in developmental processes such as epithelial geometrical packing as well as generation of forces required for blastocyst hatching.
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30.
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31.
  • Jones, Julia, et al. (författare)
  • The gut microbiome is associated with behavioural task in honey bees
  • 2018
  • Ingår i: Insectes Sociaux. - : SPRINGER BASEL AG. - 0020-1812 .- 1420-9098. ; 65:3, s. 419-429
  • Tidskriftsartikel (refereegranskat)abstract
    • The gut microbiome is recognised as playing an integral role in the health and ecology of a wide variety of animal taxa. However, the relationship between social behavioural traits and the microbial community has received little attention. Honey bees are highly social and the workers perform different behavioural tasks in the colony that cause them to be exposed to different local environments. Here we examined whether the gut microbial community composition of worker honey bees is associated with the behavioural tasks they perform, and therefore also the local environment they are exposed to. We set up five observation hives, in which all workers were matched in age and observed the behaviour of marked bees in each colony over 4 days. The gut bacterial communities of bees seen performing predominantly foraging or predominantly in nest tasks were then characterised and compared based on amplicon sequencing of the 16S rRNA gene. Our results show that some core members of the unique honey bee gut bacterial community are represented in different relative abundances in bees performing different behavioural tasks. The differentially represented bacterial taxa include some thought to be important in carbohydrate metabolism and transport, and also linked to bee health. The results suggest an influence of task-related local environment exposure and diet on the honey bee gut microbial community and identify focal core taxa for further functional analyses.
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32.
  • Kleinteich, Julia, et al. (författare)
  • Pole-to-Pole Connections : Similarities between Arctic and Antarctic Microbiomes and Their Vulnerability to Environmental Change
  • 2017
  • Ingår i: Frontiers in Ecology and Evolution. - : FRONTIERS MEDIA SA. - 2296-701X. ; 5
  • Tidskriftsartikel (refereegranskat)abstract
    • The global biogeography of microorganisms remains poorly resolved, which limits the current understanding of microbial resilience toward environmental changes. Using high-throughput 16S rRNA gene amplicon sequencing, we characterized the microbial diversity of terrestrial and lacustrine biofilms from the Arctic, Antarctic and temperate regions. Our analyses suggest that bacterial community compositions at the poles are more similar to each other than they are to geographically closer temperate habitats, with 32% of all operational taxonomic units (OTUs) co-occurring in both polar regions. While specific microbial taxa were confined to distinct regions, representing potentially endemic populations, the percentage of cosmopolitan taxa was higher in Arctic (43%) than in Antarctic samples (36%). The overlap in polar microbial OTUs may be explained by natural or anthropogenically-mediated dispersal in combination with environmental filtering. Current and future changing environmental conditions may enhance microbial invasion, establishment of cosmopolitan genotypes and loss of endemic taxa.
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33.
  • Li, S. S., et al. (författare)
  • Durable coexistence of donor and recipient strains after fecal microbiota transplantation
  • 2016
  • Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 352:6285, s. 586-589
  • Tidskriftsartikel (refereegranskat)abstract
    • Fecal microbiota transplantation (FMT) has shown efficacy in treating recurrent Clostridium difficile infection and is increasingly being applied to other gastrointestinal disorders, yet the fate of native and introduced microbial strains remains largely unknown. To quantify the extent of donor microbiota colonization, we monitored strain populations in fecal samples from a recent FMT study on metabolic syndrome patients using single-nucleotide variants in metagenomes. We found extensive coexistence of donor and recipient strains, persisting 3 months after treatment. Colonization success was greater for conspecific strains than for new species, the latter falling within fluctuation levels observed in healthy individuals over a similar time frame. Furthermore, same-donor recipients displayed varying degrees of microbiota transfer, indicating individual patterns of microbiome resistance and donor-recipient compatibilities.
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34.
  • Mohammad Ismail, Ahmad, 1993-, et al. (författare)
  • Cardiac risk stratification and adverse outcomes in surgically managed patients with isolated traumatic spine injuries
  • 2024
  • Ingår i: European Journal of Trauma and Emergency Surgery. - : Urban und Vogel Medien und Medizin Verlagsgesellsc. - 1863-9933 .- 1863-9941. ; 50:2, s. 523-530
  • Tidskriftsartikel (refereegranskat)abstract
    • INTRODUCTION: As the incidence of traumatic spine injuries has been steadily increasing, especially in the elderly, the ability to categorize patients based on their underlying risk for the adverse outcomes could be of great value in clinical decision making. This study aimed to investigate the association between the Revised Cardiac Risk Index (RCRI) and adverse outcomes in patients who have undergone surgery for traumatic spine injuries.METHODS: All adult patients (18 years or older) in the 2013-2019 TQIP database with isolated spine injuries resulting from blunt force trauma, who underwent spinal surgery, were eligible for inclusion in the study. The association between the RCRI and in-hospital mortality, cardiopulmonary complications, and failure-to-rescue (FTR) was determined using Poisson regression models with robust standard errors to adjust for potential confounding.RESULTS: A total of 39,391 patients were included for further analysis. In the regression model, an RCRI ≥ 3 was associated with a threefold risk of in-hospital mortality [adjusted IRR (95% CI): 3.19 (2.30-4.43), p < 0.001] and cardiopulmonary complications [adjusted IRR (95% CI): 3.27 (2.46-4.34), p < 0.001], as well as a fourfold risk of FTR [adjusted IRR (95% CI): 4.27 (2.59-7.02), p < 0.001], compared to RCRI 0. The risk of all adverse outcomes increased stepwise along with each RCRI score.CONCLUSION: The RCRI may be a useful tool for identifying patients with traumatic spine injuries who are at an increased risk of in-hospital mortality, cardiopulmonary complications, and failure-to-rescue after surgery.
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35.
  • Mohammad Ismail, Ahmad, 1993-, et al. (författare)
  • Sex disparities in adverse outcomes after surgically managed isolated traumatic spinal injury
  • 2024
  • Ingår i: European Journal of Trauma and Emergency Surgery. - : Urban und Vogel Medien und Medizin Verlagsgesellschaft. - 1863-9933 .- 1863-9941. ; 50:1, s. 149-155
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Traumatic spinal injury (TSI) encompasses a wide range of injuries affecting the spinal cord, nerve roots, bones, and soft tissues that result in pain, impaired mobility, paralysis, and death. There is some evidence suggesting that women may have different physiological responses to traumatic injury compared to men; therefore, this study aimed to investigate if there are any associations between sex and adverse outcomes following surgically managed isolated TSI.METHODS: Using the 2013-2019 TQIP database, all adult patients with isolated TSI, defined as a spine AIS ≥ 2 with an AIS ≤ 1 in all other body regions, resulting from blunt force trauma requiring spinal surgery, were eligible for inclusion in the study. The association between the sex and in-hospital mortality as well as cardiopulmonary and venothromboembolic complications was determined by calculating the risk ratio (RR) after adjusting for potential confounding using inverse probability weighting.RESULTS: A total of 43,756 patients were included. After adjusting for potential confounders, female sex was associated with a 37% lower risk of in-hospital mortality [adjusted RR (95% CI): 0.63 (0.57-0.69), p < 0.001], a 27% lower risk of myocardial infarction [adjusted RR (95% CI): 0.73 (0.56-0.95), p = 0.021], a 37% lower risk of cardiac arrest [adjusted RR (95% CI): 0.63 (0.55-0.72), p < 0.001], a 34% lower risk of deep vein thrombosis [adjusted RR (95% CI): 0.66 (0.59-0.74), p < 0.001], a 45% lower risk of pulmonary embolism [adjusted RR (95% CI): 0.55 (0.46-0.65), p < 0.001], a 36% lower risk of acute respiratory distress syndrome [adjusted RR (95% CI): 0.64 (0.54-0.76), p < 0.001], a 34% lower risk of pneumonia [adjusted RR (95% CI): 0.66 (0.60-0.72), p < 0.001], and a 22% lower risk of surgical site infection [adjusted RR (95% CI): 0.78 (0.62-0.98), p < 0.032], compared to male sex.CONCLUSION: Female sex is associated with a significantly decreased risk of in-hospital mortality as well as cardiopulmonary and venothromboembolic complications following surgical management of traumatic spinal injuries. Further studies are needed to elucidate the cause of these differences.
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36.
  • Tang, F., et al. (författare)
  • Upgrade Analog Readout and Digitizing System for ATLAS TileCal Demonstrator
  • 2015
  • Ingår i: IEEE Transactions on Nuclear Science. - 0018-9499 .- 1558-1578. ; 62:3, s. 1045-1049
  • Tidskriftsartikel (refereegranskat)abstract
    • The TileCal Demonstrator is a prototype for the future upgrade of the ATLAS hadron calorimeter when the Large Hadron Collider increases luminosity in year 2023 (HL-LHC). It will be used for functionality and performance tests. The Demonstrator has 48 channels of upgraded readout and digitizing electronics and a new digital trigger capability, but is backwards-compatible with the present detector system insofar as it also provides analog trigger signals and can communicate as the present system. The on-detector part of the Demonstrator is comprised of 4 identical mechanical mini-drawers, each equipped with up to 12 photomultipliers (PMTs). The on-detector electronics includes 45 Analog Front-End Boards, each serving an individual PMT; 4 Main Boards, each to control and digitize up to 12 PMT signals, and 4 corresponding high-speed Daughter Boards serving as data hubs between on-detector and off-detector electronics. It is fully compatible with the present system, accepting ATLAS triggers, timing and slow control commands for the data acquisition, detector control, and detector operation monitoring. We plan to insert one fully functional Demonstrator module into the present ATLAS TileCal detector for the LHC RUN 2 in Christmas shutdown in 2015 or 2016.
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