| 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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| 2. |
- Abbondanno, U, et al.
(författare)
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The data acquisition system of the neutron time-of-flight facility n_TOF at CERN
- 2005
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 538:1-3, s. 692-702
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Tidskriftsartikel (refereegranskat)abstract
- The n_TOF facility at CERN has been designed for the measurement of neutron capture, fission and (n, xn) cross-sections with high accuracy. This requires a flexible and-due to the high instantaneous neutron flux-almost dead time free data acquisition system. A scalable and versatile data solution has been designed based on 8-bit flash-ADCs with sampling rates up to 2 GHz and 8 Mbyte memory buffer. The software is written in C and C++ and is running on PCs equipped with RedHat Linux.
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| 3. |
- L'Huillier, A., et al.
(författare)
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Atomic physics with attosecond pulses
- 2006
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Ingår i: International Conference on Ultrafast Phenomena, UP 2006. - 1557528101 - 9781557528100
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Konferensbidrag (refereegranskat)
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| 4. |
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| 5. |
- Mabala, G. K., et al.
(författare)
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Shears band with a large dynamic moment of inertia in Bi-197
- 2005
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 25:1, s. 49-55
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in Bi-197 were studied with the AFRODITE gamma-ray array at iThemba LABS using the Ta-181(Ne-22, 6n) reaction at a beam energy of 125 MeV. A new shears band was found and linked to the low-lying states in Bi-197. Its dynamic moment of inertia, F (2), is considerably larger than the ((2)) of the shears bands in the neighbouring Pb isotopes. This is probably a result of the involvement of an additional high-K h(9/2) proton orbital.
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| 6. |
- Sansone, G., et al.
(författare)
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Attosecond excitation of electron wavepackets
- 2008
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Ingår i: Quantum Electronics and Laser Science Conference, QELS 2008. - 9781557528599
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Konferensbidrag (refereegranskat)abstract
- We present experiments, supported by time-dependent Schrödinger simulations, on the dynamics of Helium bound states after an attosecond excitation in the presence of a strong infrared laser field.
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| 7. |
- Varju, Katalin, et al.
(författare)
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Angularly resolved electron wave packet interferences
- 2006
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Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 39:18, s. 3983-3991
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Tidskriftsartikel (refereegranskat)abstract
- We study experimentally the ionization of argon atoms by a train of attosecond pulses in the presence of a strong infrared laser field, using a velocity map imaging technique. The recorded momentum distribution strongly depends on the delay between the attosecond pulses and the laser field. We interpret the interference patterns observed for different delays using numerical and analytical calculations within the strong field approximation.
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| 8. |
- Lawrie, E. A., et al.
(författare)
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Possible chirality in the doubly-odd Tl-198 nucleus: Residual interaction at play
- 2008
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 78:2
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Tidskriftsartikel (refereegranskat)abstract
- A candidate for chiral bands was found in Tl-198 for the first time in a mass region of oblate (or nonaxial with gamma >= 30 degrees) deformed nuclei. Two bands show very similar quasiparticle alignments, moments of inertia, and B(M1)/B(E2) ratios. They have a relative excitation energy of about 500 keV and different patterns of energy staggering. Calculations using the two-quasiparticle-plus-triaxial-rotor model with residual proton-neutron interaction included show that a triaxial deformation with gamma similar to 44 degrees agrees very well with all the experimental observations. Furthennore, considerable energy staggering for both partner bands was calculated for this pi h(9/2) circle times vi(13/2)(-1) configuration at gamma - 30 degrees, suggesting that chiral bands may have substantial energy staggering.
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| 9. |
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| 10. |
- Bruns, F, et al.
(författare)
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Complementary and alternative medicine experience in radiation oncology patients : first results of a multi-center approach
- 2006
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Ingår i: Trace elements and electrolytes. - 0946-2104. ; 23:4, s. 318-325
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Tidskriftsartikel (refereegranskat)abstract
- In recent years the demand and use of complementary and alternative medicine (CAM) in malignant diseases has increased noticeably. Since the general knowledge about CAM use is scant and CAM could potentially interact with standard therapies the German Working group “Trace Elements and Electrolytes in Oncology” performed a multi-centric study to comprehensively evaluate the use of CAM therapies in cancer patients treated with radiotherapy. Methods: 1,013 patients receiving consecutively radiotherapy for malignant diseases were interviewed using a standardized questionnaire including clinical and pathological tumor parameters as well as the type of CAM and reasons for CAM use. A self-assessment of patients’ personal conditions was performed in order to evaluate the subjective impact of CAM on quality of life. Results: A total of 59% of patients reported using CAM therapies. CAM use was more common in female patients, generally higher in advanced stages of disease and most common in breast cancer patients. Most frequently reported CAM therapies were vitamins (18%), mistletoe extracts (15%), selenium (10%), and other trace element preparations (7%). Multivariate logistic regression showed age, gender, tumor type and stage, and smoking behavior to be significant predictors for CAM use. A subjective improvement in quality of life due to the use of CAM was accounted for in 30% of patients. Conclusions: More than half of patients undergoing RT for cancer are using CAM therapies. Therefore, radiation oncologists should be asking for respective obtaining information about CAM use in order to avoid harmful interactions with conventional therapies. The value and potential hazards of such combined treatments have yet to be tested in further clinical studies.
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| 11. |
- Johnsson, Per, et al.
(författare)
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Attosecond electron wave packet dynamics in strong laser fields
- 2005
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Ingår i: Physical Review Letters. - 1079-7114. ; 95:1, s. 1-013001
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Tidskriftsartikel (refereegranskat)abstract
- We use a train of sub-200 attosecond extreme ultraviolet (XUV) pulses with energies just above the ionization threshold in argon to create a train of temporally localized electron wave packets. We study the energy transfer from a strong infrared (IR) laser field to the ionized electrons as a function of the delay between the XUV and IR fields. When the wave packets are born at the zero crossings of the IR field, a significant amount of energy (similar to 20 eV) is transferred from the field to the electrons. This results in dramatically enhanced above-threshold ionization in conditions where the IR field alone does not induce any significant ionization. Because both the energy and duration of the wave packets can be varied independently of the IR laser, they are valuable tools for studying and controlling strong-field processes.
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| 12. |
- Lopez, Rodrigo, et al.
(författare)
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Amplitude and phase control of attosecond light pulses
- 2005
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Ingår i: Physical Review Letters. - 1079-7114. ; 94:3
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Tidskriftsartikel (refereegranskat)abstract
- We report the generation, compression, and delivery on target of ultrashort extreme-ultraviolet light pulses using external amplitude and phase control. Broadband harmonic radiation is first generated by focusing an infrared laser with a carefully chosen intensity into a gas cell containing argon atoms. The emitted light then goes through a hard aperture and a thin aluminum filter that selects a 30-eV bandwidth around a 30-eV photon energy and synchronizes all of the components, thereby enabling the formation of a train of almost Fourier-transform-limited single-cycle 170 attosecond pulses. Our experiment demonstrates a practical method for synthesizing and controlling attosecond waveforms.
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| 13. |
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| 14. |
- Winkelbauer, M E, et al.
(författare)
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The C-elegans homologs of nephrocystin-1 and nephrocystin-4 are cilia transition zone proteins involved in chemosensory perception
- 2005
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Ingår i: Journal of Cell Science. - : The Company of Biologists. - 0021-9533 .- 1477-9137. ; 118:23, s. 5575-5587
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Tidskriftsartikel (refereegranskat)abstract
- Nephronophthisis (NPH) is a cystic kidney disorder that causes end-stage renal failure in children. Five nephrocystin (nephrocystin-1 to nephrocystin-5) genes, whose function is disrupted in NPH patients, have been identified and data indicate they form a complex at cell junctions and focal adhesions. More recently, the nephrocystin proteins have also been identified in cilia, as have multiple other cystic kidney disease related proteins. Significant insights into this cilia and cystic kidney disease connection have come from analyses in simpler eukaryotic organisms such as Caenorhabditis elegans. In this regard, we became interested in the C elegans homologs of nephrocystin-1 (nph-1) and nephrocystin-4 (nph-4) from a database screen to identify genes coordinately regulated by the ciliogenic transcription factor DAF-19. Here we show that expression of nph-1 and nph-4 is DAF-19 dependent, that their expression is restricted to ciliated sensory neurons, and that both NPH-1 and NPH-4 concentrate at the transition zones at the base of the cilia, but are not found in the cilium axoneme. In addition, NPH-4 is required for the localization of NPH-1 to this domain. Interestingly, nph-1 or nph-4 mutants have no obvious cilia assembly defects; however, they do have abnormalities in cilia-mediated sensory functions as evidenced by abnormal chemotaxis and lifespan regulation. Our data suggest that rather than having a ciliogenic role, the NPH proteins play an important function as part of the sensory or signaling machinery of this organelle. These findings suggest that the defects in human NPH patients may not be the result of aberrant ciliogenesis but abnormal cilia-sensory functions.
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| 15. |
- Johnsson, Per, et al.
(författare)
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Attosecond control of ionization by wave-packet interference
- 2007
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Ingår i: Physical Review Letters. - 1079-7114. ; 99:23
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Tidskriftsartikel (refereegranskat)abstract
- A train of attosecond pulses, synchronized to an infrared (IR) laser field, is used to create a series of electron wave packets (EWPs) that are below the ionization threshold in .helium. The ionization probability is found to strongly oscillate with the delay between the IR and attosecond fields twice per IR laser cycle. Calculations that reproduce the experimental results demonstrate that this ionization control results from interference between transiently bound EWPs created by different pulses in the train. In this way, we are able to observe, for the first time, attosecond wave-packet interference in a strongly driven atomic system.
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| 16. |
- Korherr, C, et al.
(författare)
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Identification of proangiogenic genes and pathways by high-throughput functional genomics: TBK1 and the IRF3 pathway
- 2006
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424. ; 103:11, s. 4240-4245
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Tidskriftsartikel (refereegranskat)abstract
- A genome-wide phenotype screen was used to identify factors and pathways that induce proliferation of human umbilical vein endothelial cells (HUVEC). HUVEC proliferation is a recognized marker for factors that modulate vascularization. Screening “hits” included known proangiogenic factors, such as VEGF, FGF1, and FGF2 and additional factors for which a direct association with angiogenesis was not previously described. These include the kinase TBK1 as well as Toll-like receptor adaptor molecule and IFN regulatory factor 3. All three proteins belong to one signaling pathway that mediates induction of gene expression, including a mixture of secreted factors, which, in concert, mediate proliferative activity toward endothelial cells. TBK1 as the “trigger” of this pathway is induced under hypoxic conditions and expressed at significant levels in many solid tumors. This pattern of expression and the decreased expression of angiogenic factors in cultured cells upon RNA-interference-mediated ablation suggests that TBK1 is important for vascularization and subsequent tumor growth and a target for cancer therapy.
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| 17. |
- Liesenfeld, K. H., et al.
(författare)
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Effects of the direct thrombin inhibitor dabigatran on ex vivo coagulation time in orthopaedic surgery patients: a population model analysis
- 2006
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Ingår i: Br J Clin Pharmacol. - 0306-5251. ; 62:5, s. 527-37
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: To describe the pharmacokinetic-pharmacodynamic (PK-PD) characteristics of the direct thrombin inhibitor dabigatran in hip replacement patients by assessing coagulation parameters activated partial thromboplastin time (aPTT) and ecarin clotting time (ECT), interindividual variability and factors affecting PD responses. METHODS: BISTRO I patients received oral dabigatran etexilate postsurgery for 6-10 days. Dabigatran plasma concentrations and aPTT/ECT were measured on the day of surgery, on subsequent days and at steady state. PK-PD characteristics of the dabigatran-aPTT/ECT relationships were evaluated using NONMEM V. RESULTS: The dabigatran concentration-aPTT relationship was described combining a linear and an E(max) model. Mean baseline aPTT was 33.4 s and E(max) (maximum increase in aPTT contributed by the E(max) model) was 26.9 s. The dabigatran concentration needed to attain 50% of maximum effect (EC(50)) was 94.7 ng ml(-1) and the mean slope of the linear concentration-response relationship (SLOP) was 0.0509 s ng(-1) ml(-1). Baseline aPTT and E(max) were highest following surgery and declined with time. The dabigatran concentration-ECT relationship fitted a linear model. Mean baseline ECT was 28 s and decreased with time; 50% of the maximum effect was observed after 2.9 days. SLOP decreased from 0.38 to 0.27 s ng(-1) ml(-1) with a half-life of 1.1 day, indicating greater PD effects on the day of surgery. Interindividual and residual variability was low. Covariates could not explain variability of this model. CONCLUSIONS: aPTT and ECT prolongation were directly correlated with dabigatran concentrations. Blood coagulation prolongation was most pronounced following surgery. Data suggest that ECT provides a more precise description of the anticoagulant effect than aPTT.
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| 18. |
- Mauritsson, Johan, et al.
(författare)
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Attosecond pulse trains generated using two color laser fields
- 2006
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Ingår i: Physical Review Letters. - 1079-7114. ; 97:1
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the spectral and temporal structure of high harmonic emission from argon exposed to an infrared laser field and its second harmonic. For a wide range of generating conditions, trains of attosecond pulses with only one pulse per infrared cycle are generated. The synchronization necessary for producing such trains ensures that they have a stable pulse-to-pulse carrier envelope phase, unlike trains generated from one color fields, which have two pulses per cycle and a pi phase shift between consecutive pulses. Our experiment extends the generation of phase stabilized few cycle pulses to the extreme ultraviolet regime.
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| 19. |
- Swoboda, Marko, et al.
(författare)
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Intensity dependence of laser-assisted attosecond photoionization spectra
- 2009
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Ingår i: Laser Physics. - 1054-660X. ; 19:8, s. 1591-1599
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Tidskriftsartikel (refereegranskat)abstract
- We study experimentally the influence of the intensity of the infrared (IR) probe field on attosecond pulse train (APT) phase measurements performed with the RABITT method (Reconstruction of Attosecond Beating by Interference in Two-Photon Transitions). We find that if a strong IR field is applied, the attosecond pulses will appear to have lower-than-actual chirp rates. We also observe the onset of the streaking regime in the breakdown of the weak-field RABITT conditions. We perform a Fourier-analysis of harmonic and sideband continuum states and show that the mutual phase relation of the harmonics can be extracted from higher Fourier components.
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