| 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. |
- Acciari, V. A., et al.
(författare)
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Radio Imaging of the Very-High-Energy gamma-Ray Emission Region in the Central Engine of a Radio Galaxy
- 2009
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 325:5939, s. 444-448
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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. |
- Alcorta, M., et al.
(författare)
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Nuclear Structure of C-12 from Break-up Studies in Complete Kinematics
- 2009
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Ingår i: AIP Conference Proceedings. - : AIP. - 1551-7616 .- 0094-243X. - 9780735407022 ; 1165, s. 27-30 461
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Konferensbidrag (refereegranskat)abstract
- A complete kinematics study of the B-10(He-3,p alpha alpha alpha) and B-11(He-3,d alpha alpha alpha) reactions has been performed to study the multi-particle break-up of C-12 resonances above the triple-alpha threshold. Four-particle coincidence detection gives us complete information on the direction and energy of the individual alpha particles from the decay of C-12, allowing us to extract new information on the structure of C-12 which we shall present in this contribution. We have observed gamma de-excitation of the T=1 15.11 MeV resonance using charged particle detectors, and have constructed Dalitz plots of the individual resonances in C-12 using the complete kinematics information of the alpha particles which come from their break-up.
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| 4. |
- Kirsebom, O. S., et al.
(författare)
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Observation of gamma-delayed 3 alpha breakup of the 15.11 and 12.71 MeV states in C-12
- 2009
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Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 680:1, s. 44-49
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Tidskriftsartikel (refereegranskat)abstract
- The reactions B-10(He-3, p alpha alpha alpha) at 4.9 MeV and B-11(He-3, d alpha alpha alpha) at 8.5 MeV have been used to investigate the gamma decay of states in C-12. By measuring the four-body final state in complete kinematics we are able to detect gamma transitions indirectly. We find gamma transitions from the 15.11 MeV state in C-12 to the 12.71, 11.83, 10.3 and 7.65 MeV states followed by their breakup into three alpha particles. The relative gamma-ray branching ratios obtained are (1.2 +/- 0.3), (0.32 +/- 0.12), (1.4 +/- 0.2) and (4.4 +/- 0.8)%, respectively, with the remaining (92.7 +/- 1.0)% of the gamma decays going to the bound states. We obtain Gamma(alpha)/Gamma = (2.8 +/- 1.2)% for the isospinforbidden alpha decay of the 15.11 MeV state. From the 12.71 MeV state we find gamma transitions to the 10.3 and 7.65 MeV states. The relative gamma-ray branching ratios are (0.9(-0.5)(+0.6)) and (2.6(-1.2)(+1.6))%, respectively, with the remaining (96.6(-1.3)(+1.7))% of the gamma decays going to the bound states. Finally. we discuss the relation between the beta decay of N-12 and B-12 to states in C-12 and the gamma decay of the 15.11 MeV analog in C-12 to the same states. (C) 2009 Elsevier B.V. All rights reserved.
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| 5. |
- Mårtensson, Ulrika, et al.
(författare)
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Deletion of the G protein-coupled receptor 30 impairs glucose tolerance, reduces bone growth, increases blood pressure, and eliminates estradiol-stimulated insulin release in female mice.
- 2009
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Ingår i: Endocrinology. - : The Endocrine Society. - 1945-7170 .- 0013-7227. ; 150:2, s. 687-98
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Tidskriftsartikel (refereegranskat)abstract
- In vitro studies suggest that the G protein-coupled receptor (GPR) 30 is a functional estrogen receptor. However, the physiological role of GPR30 in vivo is unknown, and it remains to be determined whether GPR30 is an estrogen receptor also in vivo. To this end, we studied the effects of disrupting the GPR30 gene in female and male mice. Female GPR30((-/-)) mice had hyperglycemia and impaired glucose tolerance, reduced body growth, increased blood pressure, and reduced serum IGF-I levels. The reduced growth correlated with a proportional decrease in skeletal development. The elevated blood pressure was associated with an increased vascular resistance manifested as an increased media to lumen ratio of the resistance arteries. The hyperglycemia and impaired glucose tolerance in vivo were associated with decreased insulin expression and release in vivo and in vitro in isolated pancreatic islets. GPR30 is expressed in islets, and GPR30 deletion abolished estradiol-stimulated insulin release both in vivo in ovariectomized adult mice and in vitro in isolated islets. Our findings show that GPR30 is important for several metabolic functions in female mice, including estradiol-stimulated insulin release.
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| 6. |
- Pinay, Gilles, et al.
(författare)
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Patterns of denitrification rates in European alluvial soils under various hydrological regimes
- 2007
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Ingår i: Freshwater Biology. - 0046-5070 .- 1365-2427. - 0046-5070 ; 52:2, s. 252-266
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Tidskriftsartikel (refereegranskat)abstract
- 1. Denitrification in floodplain soils is one of the main biological processes emitting and reducing nitrous oxide, a greenhouse gas, and the main process responsible for the buffering capacity of riparian zones against diffuse nitrate pollution. 2. The aim of this study was to measure denitrification rates under a wide range of current climatic conditions and hydrological regimes in Europe (from latitude 64 degrees N to latitude 42 degrees N and from longitude 2 degrees W to longitude 25 degrees E), in order to determine the response patterns of this microbial process under different climatic and hydrological conditions, and to identify denitrification proxies robust enough to be used at the European scale. 3. Denitrification activity was significant in all the floodplain soils studied whatever the latitude. However, we found an increase in rates of an order of magnitude from high to mid latitudes. Maximum rates (above 30 g N m(-2) month(-1)) were measured in the maritime conditions of the Trent floodplain. These rates are similar to mineralisation rates measured in alluvial soils and of the same order of magnitude as the amount of N stored in herbaceous plants in alluvial soils. 4. We used Multivariate Adaptative Regression Splines to relate the response variable denitrification with five relevant predictors, namely soil moisture, temperature, silt plus clay, nitrate content and herbaceous plant biomass. 5. Soil moisture, temperature, and nitrate were the three main control variables of microbial denitrification in alluvial soils in decreasing order of importance. 6. The model developed for denitrification with interaction effects outperformed a pure additive model. Soil moisture was involved in all interactions, emphasising its importance in predicting denitrification. 7. These results are discussed in the context of scenarios for future change in European hydrological regimes.
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| 7. |
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| 8. |
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| 9. |
- Hagell, Peter, et al.
(författare)
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The 39-Item Parkinson's Disease Questionnaire (PDQ-39) : is it a unidimensional construct?
- 2009
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Ingår i: Therapeutic advances in neurological disorders. - 1756-2856. ; 2:4, s. 205-214
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Tidskriftsartikel (refereegranskat)abstract
- The 39-item Parkinson's Disease Questionnaire, and particularly its summary index (PDQ-39SI) is a widely used patient-reported clinical trial endpoint. A basic assumption when summing items into a total score is that they represent a common variable. We therefore assessed the unidimensionality of the PDQ-39SI using Rasch and confirmatory factor analysis. Both analyses showed model misfit. Adjustment for differential item functioning and disordered response category thresholds did not improve model fit, and residual analyses showed deviation from unidimensionality. These data indicate multidimensionality and challenge the interpretation and validity of PDQ-39SI scores. Clinicians and investigators should use and interpret the PDQ-39SI with caution.
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| 10. |
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| 11. |
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| 12. |
- Kullberg, Morgan, et al.
(författare)
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Housekeeping genes for phylogenetic analysis of eutherian relationships
- 2006
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Ingår i: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 23:8, s. 1493-1503
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Tidskriftsartikel (refereegranskat)abstract
- The molecular relationship of placental mammals has attracted great interest in recent years. However, 2 crucial and conflicting hypotheses remain, one with respect to the position of the root of the eutherian tree and the other the relationship between the orders Rodentia, Lagomorpha (rabbits, hares), and Primates. Although most mitochondrial (mt) analyses have suggested that rodents have a basal position in the eutherian tree, some nuclear data in combination with mt-rRNA genes have placed the root on the so-called African clade or on a branch that includes this clade and the Xenarthra (e.g., anteater and armadillo). In order to generate a new and independent set of molecular data for phylogenetic analysis, we have established cDNA sequences from different tissues of various mammalian species. With this in mind, we have identified and sequenced 8 housekeeping genes with moderately fast rate of evolution from 22 placental mammals, representing I I orders. In order to determine the root of the eutherian tree, the same genes were also sequenced for 3 marsupial species, which were used as outgroup. Inconsistent with the analyses of nuclear + mt-rRNA gene data, the current data set did not favor a basal position of the African clade or Xenarthra in the eutherian tree. Similarly, by joining rodents and lagomorphs on the same basal branch (Glires hypothesis), the data set is also inconsistent with the tree commonly favored in mtDNA analyses. The analyses of the currently established sequences have helped examination of problematic parts in the eutherian tree at the same time as they caution against suggestions that have claimed that basal eutherian relationships have been conclusively settled.
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| 13. |
- Magnussen, S., et al.
(författare)
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What people believe about memory
- 2006
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Ingår i: Memory. - : Informa UK Limited. - 0965-8211 .- 1464-0686. ; 14:5, s. 595-613
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Tidskriftsartikel (refereegranskat)abstract
- Two representative samples of adult Norwegians (n=2000) were asked a set of general and specific questions regarding their beliefs and opinions about human memory. The results indicate that on many questions, such as time of the earliest memories, inhibiting effects of collaboration, and memory for dramatic versus ordinary events, the views of the general public concurred with current research findings, and people in general had realistic views about their own memory performance. On other questions, such as the reliability of olfactory as compared with visual and auditory memory, the memory of small children in comparison with that of adults, the likelihood of repression of adult traumatic memories, and on more general questions such as the possibility of training memory and the capacity limitations of long-term memory, a large proportion of the participants expressed views that are less supported by scientific evidence. Implications of these findings are briefly discussed. © 2006 Psychology Press Ltd.
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| 14. |
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| 15. |
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| 16. |
- Nilsson, Maria H
(författare)
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Balance performance in people with Parkinson’s disease. Effects of subthalamic Deep Brain Stimulation.
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aims of this work were to investigate if Deep Brain Stimulation in the subthalamic nuclei (STN) affected balance, fear of falling and falls in people with Parkinson's disease. The effect of STN stimulation alone was investigated in Papers I, II and III. The participants were evaluated after an overnight withdrawal of anti-PD medication and with the STN stimulation turned off and on. Functional balance performance was evaluated by using the Berg balance scale (BBS: higher scores denote "better" balance). STN stimulation alone significantly increased the BBS-scores both at short and long-term follow-ups (3 years). There are thus no indices that STN stimulation by itself affects functional balance performance negatively as a side effect. Timed tests showed furthermore statistical improvements. The participants’ ratings showed an increased fall-related self-efficacy when the STN stimulation was turned on (Paper III). Force-plate measurements (posturography) were also conducted (Paper III). These results showed no statistical significant differences, which may be a consequence of the limited sample size. Three years after surgery, the dosage of anti-PD medication was reduced by approximately 50% (Paper II). The anti-PD medication further increased the BBS-scores. In Paper IV falls (fall-diary) were registered both before and after surgery. The rate of falls was not significantly different after surgery. Further and larger studies are warranted. One year after surgery, the participants’ ratings showed an increased fall-related self-efficacy during more complex activities and decreased activity avoidance due to the risk of falling. These findings indicate a positive effect on activities and participation.
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| 17. |
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| 18. |
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| 19. |
- Nilsson, Maria H, et al.
(författare)
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Freezing of Gait Questionnaire: validity and reliability of the Swedish version.
- 2009
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Ingår i: Acta Neurologica Scandinavica. - : Hindawi Limited. - 1600-0404 .- 0001-6314. ; 120:5, s. 331-334
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Tidskriftsartikel (refereegranskat)abstract
- Background - Patient-reported assessments of freezing of gait (FOG) in Parkinson's disease (PD), such as the FOG questionnaire (FOGQ), are needed because FOG is difficult to assess objectively. However, the measurement properties of the FOGQ have been sparsely assessed. Aim - To assess the measurement properties of the Swedish FOGQ, and to explore relationships between FOGQ scores and other aspects of PD. Methods - Thirty-seven people with PD were assessed with the FOGQ, Unified PD Rating Scale (UPDRS), Hoehn and Yahr (HY), Falls-Efficacy Scale [FES(S)], timed gait tests, and the SF-36 physical functioning (PF) scale. Results - Mean (SD) FOGQ item scores ranged between 1.3 and 2.1 (1.2-1.5); corrected item-total correlations ranged between 0.80 and 0.94. Reliability was 0.95. Mean (SD) and median (q1-q3) FOGQ scores were 9.6 (7.4) and 10 (2-15). Floor and ceiling effects were
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| 20. |
- Nilsson, Maria H, et al.
(författare)
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Functional balance performance in patients with Parkinson's disease after long-term treatment with subthalamic nucleus high-frequency stimulation
- 2008
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Ingår i: Parkinsonism & Related Disorders. - : Elsevier BV. - 1873-5126 .- 1353-8020. ; 14:4, s. 291-297
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Tidskriftsartikel (refereegranskat)abstract
- The aim was to investigate if functional balance performance in patients with Parkinson's disease (PD) was affected by long-term (3 years) treatment with bilateral subthalamic nucleus (STN) high-frequency stimulation. Thirty-five patients were consecutively included, and 28 patients completed the study (mean age 62 years, SD 6.5). The Berg Balance Scale (BBS) was assessed preoperatively and 1 and 3 years postoperatively (with and without anti-PD medication and with the STN stimulation turned OFF or ON). Although the balance performance of patients with PD decreased over time, the functional balance performance was still positively affected by STN stimulation alone 3 years after surgery.
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| 21. |
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| 22. |
- Nilsson, Maria H, et al.
(författare)
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The effects of high frequency subthalamic stimulation on balance performance and fear of falling in patients with Parkinson's disease.
- 2009
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Ingår i: Journal of NeuroEngineering and Rehabilitation. - : Springer Science and Business Media LLC. - 1743-0003. ; 6:Apr 30
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Balance impairment is one of the most distressing symptoms in Parkinson's disease (PD) even with pharmacological treatment (levodopa). A complementary treatment is high frequency stimulation in the subthalamic nucleus (STN). Whether STN stimulation improves postural control is under debate. The aim of this study was to explore the effects of STN stimulation alone on balance performance as assessed with clinical performance tests, subjective ratings of fear of falling and posturography. METHODS: Ten patients (median age 66, range 59-69 years) with bilateral STN stimulation for a minimum of one year, had their anti-PD medications withdrawn overnight. Assessments were done both with the STN stimulation turned OFF and ON (start randomized). In both test conditions, the following were assessed: motor symptoms (descriptive purposes), clinical performance tests, fear of falling ratings, and posturography with and without vibratory proprioceptive disturbance. RESULTS: STN stimulation alone significantly (p = 0.002) increased the scores of the Berg balance scale, and the median increase was 6 points. The results of all timed performance tests, except for sharpened Romberg, were significantly (p or= 0.109) in torque variance values when comparing the two test situations. This applied both during quiet stance and during the periods with vibratory stimulation, and it was irrespective of visual input and sway direction. CONCLUSION: In this sample, STN stimulation alone significantly improved the results of the clinical performance tests that mimic activities in daily living. This improvement was further supported by the patients' ratings of fear of falling, which were less severe with the STN stimulation turned ON. Posturography could not be performed by three out of the ten patients when the stimulation was turned OFF. The posturography results of the seven patients with complete data showed no significant differences due to STN stimulation.
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| 23. |
- Nilsson, Maria, et al.
(författare)
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The antibacterial activity of peptides derived from human beta-2 glycoprotein I is inhibited by protein H and M1 protein from Streptococcus pyogenes.
- 2008
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Ingår i: Molecular Microbiology. - : Wiley. - 1365-2958 .- 0950-382X. ; 67:3, s. 482-492
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Tidskriftsartikel (refereegranskat)abstract
- During the last years, the importance of antibacterial peptides has attracted considerable attention. We report here that peptides derived from the fifth domain of beta-2 glycoprotein I (beta(2)GPI), a human heparin binding plasma protein, have antibacterial activities against Gram-positive and Gram-negative bacteria. Streptococcus pyogenes, an important human pathogen that can survive and grow in human blood, has developed mechanisms to escape the attack by these peptides. Thus, protein H and M1 protein, two surface proteins of the highly pathogenic S. pyogenes AP1 strain, bind full-length beta(2)GPI and thereby prevent the processing of beta(2)GPI by proteases from polymorphonuclear neutrophils (PMNs) into antibacterial peptides. In addition, protein H and M1 protein, released from the bacterial cell wall by PMN-derived proteases, bind to, and inhibit the activity of, beta(2)GPI-derived antibacterial peptides. Taken together, the data suggest that the interaction between the streptococcal proteins and beta(2)GPI or beta(2)GPI-derived peptides presents a novel mechanism to resist an antibacterial attack by beta(2)GPI-cleavage products.
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