1. |
- Abelev, Betty, et al.
(författare)
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Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV
- 2013
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41
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Tidskriftsartikel (refereegranskat)abstract
- Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < P-T,P-assoc < P-T,P-trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p(T) bins, and the widths show no significant evolution with event multiplicity or p(T). These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
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2. |
- Abelev, Betty, et al.
(författare)
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Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :11
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Tidskriftsartikel (refereegranskat)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
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3. |
- Abelev, Betty, et al.
(författare)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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4. |
- Brunner, Marcus, et al.
(författare)
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Towards Ambient Networks Management
- 2005. - 1
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Ingår i: IEEE MATA 2005 Second International Workshop on Mobility Aware Technologies and Applications.
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Konferensbidrag (refereegranskat)
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5. |
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6. |
- Graf, L., et al.
(författare)
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The Role of Structural Flexibility and Stability in the Interaction of Serine Proteases with their Inhibitors
- 2015
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Ingår i: Current Protein & Peptide Science. - 1389-2037. ; 16:6, s. 521-531
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Forskningsöversikt (refereegranskat)abstract
- Serine proteases and their natural inhibitors have long been served as excellent models for studying (primary, secondary and tertiary) structure - activity relationships of biologically interacting proteins. As protein flexibility has been accepted as a "fourth dimension" of the protein structure, its contribution to the binding process has gained much interest. In this article we review extreme cases of serine protease interactions with canonical serine protease inhibitors that provide unique insights into the dynamics of protein-protein interactions. The major conclusions of our review article are: a) taxon-specific inhibitory effects of two highly homologous protease inhibitors from Schistocerca gregaria (SGCI and SGTI), as investigated by H/D exchange experiments and NMR spectroscopy, are due to their differential flexibilities, b) stabilities of some protease and inhibitor complexes, the wide-spread and increased flexibility of some segments in the protein-protein complexes, as studied by X-ray crystallography and NMR-spectroscopy, appear to be proportional to the physical stability of the complex.
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7. |
- Karlberg, Anna, et al.
(författare)
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Analysis of global changes in gene expression during activity-dormancy cycle in hybrid aspen apex
- 2010
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Ingår i: Plant Biotechnology. - : Japanese Society for Plant Cell and Molecular Biology. - 1342-4580 .- 1347-6114. ; 27, s. 1-16
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Tidskriftsartikel (refereegranskat)abstract
- Perennial plants such as the long-lived trees of boreal forest cycle between periods of active growth and dormancy. Transition from active growth to dormancy is induced by short day (SD) signal. Once dormancy is established, prolonged exposure to low temperature is required for breaking dormancy before warm temperatures can induce growth. We have studied global changes in gene expression in the apex of model plant hybrid aspen during the distinct stages of activity-dormancy cycle. Our data shows that all stages of activity-dormancy cycle in the apex are associated with substantial modulation of the transcriptome. Detailed analysis of core cell cycle genes indicates that with the exception of plant specific B-type CDKs, all of the other CDKs are regulated post-transcriptionally during growth cessation. SD signal appears to target the expression of cyclin genes that are down regulated during growth arrest. Several of the cold hardiness related genes e. g. dehydrins are induced during transition to dormancy although temperature is not reduced and the up-regulation of the expression of these genes does not appear to rely on SD mediated induction of classical CBF transcription factors. Our results suggest that transcriptional control plays a key role in modulation of hormones such as ABA and GA that are known to play a central role in various processes during activity-dormancy cycle. Analysis of histone and DNA modification genes indicates that chromatin remodeling could be involved in coordinating global changes in gene expression during activity-dormancy cycle.
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8. |
- Karlberg, Anna, et al.
(författare)
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Analysis of global changes in gene expression during activity-dormancy cycle in hybrid aspen apex
- 2010
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Ingår i: Plant Biotechnology. - 1342-4580. ; 27:1, s. 1-16
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Tidskriftsartikel (refereegranskat)abstract
- Perennial plants such as the long-lived trees of boreal forest cycle between periods of active growth and dormancy. Transition from active growth to dormancy is induced by short day (SD) signal. Once dormancy is established, prolonged exposure to low temperature is required for breaking dormancy before warm temperatures can induce growth. We have studied global changes in gene expression in the apex of model plant hybrid aspen during the distinct stages of activity-dormancy cycle. Our data shows that all stages of activity-dormancy cycle in the apex are associated with substantial modulation of the transcriptome. Detailed analysis of core cell cycle genes indicates that with the exception of plant specific B-type CDKs, all of the other CDKs are regulated post-transcriptionally during growth cessation. SD signal appears to target the expression of cyclin genes that are down regulated during growth arrest. Several of the cold hardiness related genes e. g. dehydrins are induced during transition to dormancy although temperature is not reduced and the up-regulation of the expression of these genes does not appear to rely on SD mediated induction of classical CBF transcription factors. Our results suggest that transcriptional control plays a key role in modulation of hormones such as ABA and GA that are known to play a central role in various processes during activity-dormancy cycle. Analysis of histone and DNA modification genes indicates that chromatin remodeling could be involved in coordinating global changes in gene expression during activity-dormancy cycle.
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9. |
- Molnár, Tamás, et al.
(författare)
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Comparison of complexes formed by a crustacean and a vertebrate trypsin with bovine pancreatic trypsin inhibitor - the key to achieving extreme stability?
- 2013
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Ingår i: The FEBS journal. - : Wiley. - 1742-4658 .- 1742-464X. ; 280:22, s. 5750-5763
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Tidskriftsartikel (refereegranskat)abstract
- This paper provides evidence for the extremely high resistance of a complex of crayfish trypsin (CFT) and bovine pancreatic trypsin inhibitor (BPTI) against heating and chemical denaturing agents such as sodium dodecyl sulfate (SDS) and urea. To dissociate this complex, 15min boiling in SDS was necessary, compared to a complex of bovine trypsin (BT) (EC 3.4.21.4) and BPTI, which dissociates in SDS without boiling. The CFT-BPTI complex remained stable even in 9m urea, while the BT-BPTI complex started to dissociate at concentrations of approximately 4m urea. The melting temperatures of the BT-BPTI and CFT-BPTI complexes, as determined by differential scanning calorimetry, were found to be 79.6 and 100.1°C, respectively. The behaviour of the apo-enzymes - CFT was found to have a less stable structure compared to BT - did not provide a definite indication regarding the differential effects on their stabilities. To explore the structural features responsible for this extreme stability, we crystallized CFT in complex with BPTI, and identified extended contacts compared to the BT-BPTI complex. Comparison of the B-factors of similar trypsin-trypsin inhibitor complexes suggests that molecular flexibility of the components is also required for the strong protein-protein interaction. Although the structural reason for the extreme stability of the CFT-BPTI complex is not yet fully understood, our study may be a starting point for the development of new protein complexes with enhanced stability.
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10. |
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