| 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. |
- Bunce, R. G. H., et al.
(författare)
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A standardized procedure for surveillance and monitoring European habitats and provision of spatial data
- 2008
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Ingår i: Landscape Ecology. - : Springer Science and Business Media LLC. - 0921-2973 .- 1572-9761. ; 23, s. 11-25
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Tidskriftsartikel (refereegranskat)abstract
- Both science and policy require a practical, transmissible, and reproducible procedure for surveillance and monitoring of European habitats, which can produce statistics integrated at the landscape level. Over the last 30 years, landscape ecology has developed rapidly, and many studies now require spatial data on habitats. Without rigorous rules, changes from baseline records cannot be separated reliably from background noise. A procedure is described that satisfies these requirements and can provide consistent data for Europe, to support a range of policy initiatives and scientific projects. The methodology is based on classical plant life forms, used in biogeography since the nineteenth century, and on their statistical correlation with the primary environmental gradient. Further categories can therefore be identified for other continents to assist large scale comparisons and modelling. The model has been validated statistically and the recording procedure tested in the field throughout Europe. A total of 130 General Habitat Categories (GHCs) is defined. These are enhanced by recording environmental, site and management qualifiers to enable flexible database interrogation. The same categories are applied to areal, linear and point features to assist recording and subsequent interpretation at the landscape level. The distribution and change of landscape ecological parameters, such as connectivity and fragmentation, can then be derived and their significance interpreted.
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| 5. |
- Gustafson, Johan, et al.
(författare)
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Structure of a thin oxide film on Rh(100)
- 2005
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Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 71:11
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Tidskriftsartikel (refereegranskat)abstract
- The initial oxidation of Rh(100) has been studied using high resolution core level spectroscopy, low energy electron diffraction, surface x-ray diffraction, scanning tunneling microscopy, and density functional theory. We report a structural study of an oxygen induced structure displaying a c(8x2) periodicity at an oxygen pressure above 10(-5) mbar and using a sample temperature of 700 K. Our experimental and theoretical data demonstrate that this structure is due to the formation of a thin surface oxide with a hexagonal trilayer O-Rh-O structure.
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| 7. |
- Rodríguez, M, et al.
(författare)
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Reduction of atherosclerotic nanoplaque formation and size by Ginkgo biloba (EGb 761) in cardiovascular high-risk patients
- 2007
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Ingår i: Atherosclerosis. - : Elsevier BV. - 0021-9150 .- 1879-1484. ; 192:2, s. 438-444
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Tidskriftsartikel (refereegranskat)abstract
- Coating a silica surface with the isolated lipoprotein receptor proteoheparan sulfate (HS-PG) from arterial endothelium and vascular matrices and adding both the atherogenic VLDL/IDL/LDL lipid fraction in its native composition and Ca2+ ions, we could observe in vitro the earliest stages of atherosclerotic plaque development by ellipsometric techniques (patent EP 0 946 876). This so-called nanoplaque formation is represented by the ternary aggregational complex of the HS-PG receptor, lipoprotein particles and calcium ions. The model was validated in several clinical studies on statins in cardiovascular high-risk patients. In eight patients who had undergone an aortocoronary bypass operation, the reduction of atherosclerotic nanoplaque formation amounted to 11.9±2.5% (p<0.0078) and of nanoplaque size to 24.4±8.1% (p<0.0234), respectively, after a 2-month therapy with Ginkgo biloba extract (2× 120mg daily, EGb 761). Additionally, superoxide dismutase (SOD) activity was upregulated by 15.7±7.0% (p<0.0391), the quotient oxLDL/LDL lowered by 17.0±5.5% (p<0.0234) and lipoprotein(a) concentration decreased by 23.4±7.9% (p<0.0234) in the patients’ blood. The concentration of the vasodilating substances cAMP and cGMP was augmented by 37.5±9.1% (p<0.0078) and 27.7±8.3% (p<0.0156), respectively. A multiple regression analysis between the patients’ VLDL/IDL/LDL lipoprotein fraction applied in the ellipsometry measurements as well as the further risk factors oxLDL/LDL and Lp(a) on the one hand and changes in nanoplaque formation on the other hand reveals a basis for a mechanistic explanation of nanoplaque reduction under ginkgo treatment. The atherosclerosis inhibiting effect is possibly due to an upregulation in the body's own radical scavenging enzymes and an attenuation of the risk factors oxLDL/LDL and Lp(a).
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| 8. |
- Siegel, G., et al.
(författare)
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Ginkgo biloba and its Influence on Nanoplaque Formation and Vascular Function
- 2008
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Ingår i: Diabetes stoffwechsel und herz. - 1861-7603. ; 17, s. S23-S35
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Tidskriftsartikel (refereegranskat)abstract
- Background: In a pilot study, we demonstrated the beneficial effects of Ginkgo biloba (EGb 761) on atherosclerotic nanoplaque formation and size, the oxLDL/LDL quotient and the lipoprotein(a) concentration, the increase in superoxide dismutase activity, as well as the cAMP and cGMP concentrations. Method: The measurable variables formerly used were supplemented by a biomarker spectrum, through which the latest parameter and markers of plaque stability and progression, oxidative stress, and inflammation could be determined. Results: In 11 patients with early-stage metabolic syndrome, atherosclerotic nanoplaque formation fell by 14.3 +/- 2.9 (p < 0.0077) and nanoplaque size by 23.4 +/- 3.7 % (p < 0.0004), respectively, after a two-month regime with Ginkgo biloba extract. Superoxide dismutase and glutathione peroxidase (GPx) activities were upregulated by 19.6 +/- 10.0 % (p < 0.0785) and 11.6 +/- 2.3 % (p < 0.001), respectively. The quotient oxLDL/LDL fell by 21.0 +/- 4.3 % (p < 0.002), and lipoprotein(a) concentration by 26.3 t 4.8 % (p < 0.001). The concentrations of cAMP and cGMP were augmented by43.5 12.0% (p < 0.001)and 32.9 +/- 10.4% (p < 0.001), respectively. The serum Call concentration fell by 5.4 +/- 1.6 % (p < 0.0076). We could also show a favourable development of 8-iso-PGF(2 alpha), oxLDL/LDL, SOD, GPx, hsCRP MPO,TNF alpha, TGF beta(1), and MMP-9. Conclusion: Ginkgo with its pleiotropic effects should be assigned a fixed rank among the anti-ageing medical therapeutics.
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| 9. |
- van den Kommer, Tessa N, et al.
(författare)
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Classification models for early identification of persons at risk for dementia in primary care: an evaluation in a sample aged 80 years and older.
- 2009
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Ingår i: Dementia and geriatric cognitive disorders. - : S. Karger AG. - 1421-9824 .- 1420-8008. ; 28:6, s. 567-577
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To evaluate previously developed classification models to make implementation in primary care possible and aid early identification of persons at risk for dementia. METHODS: Data were drawn from the OCTO-Twin study. At baseline, 521 persons >or= 80 years of age were nondemented, and for 387 a blood sample was available. Predictors of dementia were collected and analyzed in initially nondemented persons using generalized estimating equations and Cox survival analyses. RESULTS: In the basic model using predictors already known or easily obtained (basic set), the mean 2-year predictive value increased from 6.9 to 28.8% in persons with memory complaints and an MMSE score
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| 10. |
- Williams, H., et al.
(författare)
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Density functional theory with hybrid functionals applied to defects in GaAs surfaces: Effect of doping
- 2008
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Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 78:20
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Tidskriftsartikel (refereegranskat)abstract
- We have analyzed the influence of a Ga vacancy on electronic properties of GaAs(110) by scanning tunneling microscopy (STM), ab initio electronic structure simulations based on density functional theory with Perdew-Becke-Ernzerhof and Heyd-Scuseria-Ernzerhof functionals and STM simulations. We find that the HSE03 functional improves the description of the band gap of the semiconductor surface in line with recent bulk simulations. The inclusion of doping in the crystal significantly affects the position of the band gap in the electronic structure and the signature of the defect. The simulated STM images show good correlation with the main features of the experimental images only for hybrid-functional simulations and only if the effects of doping and band bending are included in the description.
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