| 1. |
- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 4. |
- Meyer, H., et al.
(författare)
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Overview of physics results from MAST
- 2009
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 49:10, s. 104017-
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Tidskriftsartikel (refereegranskat)abstract
- Several improvements to the MAST plant and diagnostics have facilitated new studies advancing the physics basis for ITER and DEMO, as well as for future spherical tokamaks (STs). Using the increased heating capabilities P-NBI <= 3.8 MW H-mode at I-P = 1.2 MA was accessed showing that the energy confinement on MAST scales more weakly with I-P and more strongly with B-t than in the ITER IPB98(y, 2) scaling. Measurements of the fuel retention of shallow pellets extrapolate to an ITER particle throughput of 70% of its original designed total throughput capacity. The anomalous momentum diffusion, chi(phi), is linked to the ion diffusion, chi(i), with a Prandtl number close to P-phi approximate to chi(phi)/chi(i) approximate to 1, although chi(i) approaches neoclassical values. New high spatial resolution measurements of the edge radial electric field, E-r, show that the position of steepest gradients in electron pressure and E-r (i.e. shearing rate) are coincident, but their magnitudes are not linked. The T-e pedestal width on MAST scales with root beta(ped)(pol) rather than rho(pol). The edge localized mode (ELM) frequency for type-IV ELMs, new in MAST, was almost doubled using n = 2 resonant magnetic perturbations from a set of four external coils (n = 1, 2). A new internal 12 coil set (n <= 3) has been commissioned. The filaments in the inter-ELM and L-mode phase are different from ELM filaments, and the characteristics in L-mode agree well with turbulence calculations. A variety of fast particle driven instabilities were studied from 10 kHz saturated fishbone like activity up to 3.8 MHz compressional Alfven eigenmodes. Fast particle instabilities also affect the off-axis NBI current drive, leading to fast ion diffusion of the order of 0.5 m(2) s(-1) and a reduction in the driven current fraction from 40% to 30%. EBW current drive start-up is demonstrated for the first time in a ST generating plasma currents up to 55 kA. Many of these studies contributed to the physics basis of a planned upgrade to MAST.
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| 6. |
- Power, M. J., et al.
(författare)
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Changes in fire regimes since the Last Glacial Maximum : an assessment based on a global synthesis and analysis of charcoal data
- 2008
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Ingår i: Climate Dynamics. - : Springer Science and Business Media LLC. - 0930-7575 .- 1432-0894. ; 30:7-8, s. 887-907
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Tidskriftsartikel (refereegranskat)abstract
- Fire activity has varied globally and continuously since the last glacial maximum (LGM) in response to long-term changes in global climate and shorter-term regional changes in climate, vegetation, and human land use. We have synthesized sedimentary charcoal records of biomass burning since the LGM and present global maps showing changes in fire activity for time slices during the past 21,000 years (as differences in charcoal accumulation values compared to pre-industrial). There is strong broad-scale coherence in fire activity after the LGM, but spatial heterogeneity in the signals increases thereafter. In North America, Europe and southern South America, charcoal records indicate less-than-present fire activity during the deglacial period, from 21,000 to ∼11,000 cal yr BP. In contrast, the tropical latitudes of South America and Africa show greater-than-present fire activity from ∼19,000 to ∼17,000 cal yr BP and most sites from Indochina and Australia show greater-than-present fire activity from 16,000 to ∼13,000 cal yr BP. Many sites indicate greater-than-present or near-present activity during the Holocene with the exception of eastern North America and eastern Asia from 8,000 to ∼3,000 cal yr BP, Indonesia and Australia from 11,000 to 4,000 cal yr BP, and southern South America from 6,000 to 3,000 cal yr BP where fire activity was less than present. Regional coherence in the patterns of change in fire activity was evident throughout the post-glacial period. These complex patterns can largely be explained in terms of large-scale climate controls modulated by local changes in vegetation and fuel load.
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| 8. |
- Balgobind, Brian V, et al.
(författare)
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Novel prognostic subgroups in childhood 11q23/MLL-rearranged acute myeloid leukemia : results of an international retrospective study.
- 2009
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 114:12, s. 2489-2496
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Tidskriftsartikel (refereegranskat)abstract
- Translocations involving chromosome 11q23 frequently occur in pediatric acute myeloid leukemia (AML) and are associated with poor prognosis. In most cases, the MLL gene is involved, and more than 50 translocation partners have been described. Clinical outcome data of the 11q23-rearranged subgroups are scarce because most 11q23 series are too small for meaningful analysis of subgroups, although some studies suggest that patients with t(9;11)(p22;q23) have a more favorable prognosis. We retrospectively collected outcome data of 756 children with 11q23- or MLL-rearranged AML from 11 collaborative groups to identify differences in outcome based on translocation partners. All karyotypes were centrally reviewed before assigning patients to subgroups. The event-free survival of 11q23/MLL-rearranged pediatric AML at 5 years from diagnosis was 44% (+/- 5%), with large differences across subgroups (11% +/- 5% to 92% +/- 5%). Multivariate analysis identified the following subgroups as independent prognostic predictors: t(1;11)(q21;q23) (hazard ratio [HR] = 0.1, P = .004); t(6;11)(q27;q23) (HR = 2.2, P < .001); t(10;11)(p12;q23) (HR = 1.5, P = .005); and t(10;11)(p11.2;q23) (HR = 2.5, P = .005). We could not confirm the favorable prognosis of the t(9;11)(p22;q23) subgroup. We identified large differences in outcome within 11q23/MLL-rearranged pediatric AML and novel subgroups based on translocation partners that independently predict clinical outcome. Screening for these translocation partners is needed for accurate treatment stratification at diagnosis.
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| 9. |
- Hasle, Henrik, et al.
(författare)
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Monosomy 7 and deletion 7q in children and adolescents with acute myeloid leukemia : an international retrospective study.
- 2007
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Ingår i: Blood. - 0006-4971. ; 109:11, s. 4641-7
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Tidskriftsartikel (refereegranskat)abstract
- Monosomy 7 (-7) and deletion 7q \del(7q)] are rare in childhood acute myeloid leukemia (AML). We retrospectively collected data on 258 children with AML or refractory anemia with excess blasts in transformation (RAEB-T) and -7 or del(7q) with or without other cytogenetic aberrations \+/- other]. Karyotypes included -7 (n = 90), -7 other (n = 82), del(7q) (n = 21), and del(7q) other (n = 65). Complete remission (CR) was achieved in fewer patients with -7 +/- other compared with del(7q) +/- other (61% versus 89%, P < .001). Overall, the 5-year survival rate was 39% (SE, 3%). Survival was superior in del(7q) +/- other compared with -7 +/- other (51% versus 30%, P < .01). Cytogenetic aberrations considered favorable in AML \t(8;21)(q22;q22), inv(16)(p13q22), t(15;17)(q22;q21), t(9;11)(p22;q23)] (n = 24) were strongly associated with del(7q) and a higher 5-year survival rate compared with del(7q) without favorable cytogenetics (75% versus 46%, P = .03). Patients with -7 and inv(3),-5/del(5q), or + 21 had a 5-year survival rate of 5%. Stem cell transplantation analyzed as a time-dependent variable had no impact on overall survival. However, patients not achieving CR had a 31% survival rate after stem cell transplantation. Childhood AML with chromosome 7 aberrations represents a heterogeneous group of disorders with additional cytogenetic aberrations having a major prognostic impact which should be reflected in future risk-group stratification.
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| 10. |
- Moorman, AV, et al.
(författare)
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No prognostic effect of additional chromosomal abnormalities in children with acute lymphoblastic leukemia and 11q23 abnormalities
- 2005
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Ingår i: Leukemia. - London : Nature Publishing Group. - 0887-6924 .- 1476-5551. ; 19:4, s. 557-563
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Tidskriftsartikel (refereegranskat)abstract
- This study characterized the additional chromosomal abnormalities (ACA) associated with 11q23 rearrangements in 450 infants and children with acute lymphoblastic leukemia ( ALL) and examined the impact of these ACA on survival. Overall, 213 (47%) cases had ACA but the incidence varied according to patient age and 11q23 subgroup. Infants and patients with t(4; 11)(q21; q23) had the lowest incidence of ACA (50/182 (27%) and 57/216 (26%) respectively), whereas patients with del( 11)( q23) had the highest incidence (66/93 (71%)). Del( 11)( q23) abnormalities were heterogeneous and occasionally secondary to t( 9; 22)(q34; q11.2). Thus, patients with del( 11)( q23) comprised a separate biological entity, which was clearly distinct from those with an 11q23 translocation. The most frequent specific ACA were trisomy X ( n = 38), abnormal 12p ( n = 32), abnormal 9p ( n = 28) and del( 6q) ( n = 19). The presence of ACA did not change the 5 year event-free survival estimates among children (56% (95% CI 46 - 65%) vs 62% (54 - 69%)) or infants (22% ( 15 - 29%) vs 18% ( 9 - 29%)), nor when the different 11q23 subgroups were analyzed separately. This study has conclusively demonstrated that there is no prognostic effect of secondary chromosomal changes in association with 11q23 abnormalities in childhood ALL. However, characterization of these ACA is important to determine their potential role in initiation of MLL driven leukemogenesis.
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