| 1. |
- Aamodt, K., et al.
(author)
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The ALICE experiment at the CERN LHC
- 2008
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In: Journal of Instrumentation. - 1748-0221. ; 3:S08002
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Research review (peer-reviewed)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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| 3. |
- Arner, Marianne, et al.
(author)
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CPUP - årsrapport 2007
- 2007
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Book (pop. science, debate, etc.)abstract
- Detta är den andra årsrapporten för CPUP (Uppföljningsprogram för cerebral pares) som nationellt kvalitetsregister.
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| 4. |
- Aspenberg, Per, 1949-, et al.
(author)
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Fixed or loose? Dichotomy in RSA data for cemented cups
- 2008
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In: Acta Orthopaedica. - Basingstoke : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; 79:4, s. 467-473
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Journal article (peer-reviewed)abstract
- BACKGROUND AND PURPOSE: Roentgen stereometric analysis (RSA) cannot discern whether a single prosthesis is fixed or migrating below the detection level. Samples of patients usually show migration values that appear to be continuously distributed. Is there such continuity, or is there a dichotomy between stable and migrating prostheses? The hypothesis of a dichotomy has, to our knowledge, not been tested. We present an exploratory evaluation of such a dichotomy using a mixture distribution algorithm. METHODS: We analyzed the migration (as determined by RSA) of 147 cemented acetabular cups of 7 different designs by using a new set of algorithms for frequency distribution analysis called Rmix. RESULTS: We first analyzed a migration vector, regardless of direction. After 2 years there was a significant dichotomy between 2 lognormal subgroups within the sample. Although some types of cups were over-represented in one of the subgroups, neither cup design, sex, nor operating department could explain the dichotomy into two groups, which appears to reflect the existence of two basically different types of behavior of the cups. We next analyzed the migration along the 3 axes in space, and found a similar dichotomy. During the second year, around 80% of the patients belonged to a distinct, normally distributed subgroup with a mean not different from 0 mm and a small variation. The remainder differed significantly from this subgroup and showed migration. INTERPRETATION: There is a dichotomy in migration pattern. During the second postoperative year, most cups belonged to a subpopulation that appeared stable. The remainder is probably at risk of loosening. For a single type of prosthesis, the relative size of the stable subgroup may be a good index of the expected performance. The possibility of detecting subgroups within a seemingly continuous sample might be useful in many fields of medicine.
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| 5. |
- Borg, Mattias, et al.
(author)
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Characterization of GaSb nanowires grown by MOVPE
- 2008
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In: Journal of Chrystal Growth. - : Elsevier BV. - 0022-0248. ; 310:23, s. 5119-5122
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Conference paper (peer-reviewed)abstract
- We report the growth and characterization of GaSb nanowires grown by MOVPE. The structural properties of the nanowires are investigated by the means of transmission electron microscopy, X-ray diffraction and single nanowire photoluminescence. The measurements confirm a high material quality in the GaSb nanowires. Also, a back-gated nanowire transistor structure is used to extract values for the polarity and resistivity of the GaSb. Finally, a simple kinetic model is presented to explain the non-linear time dependence of the GaSb nanowire growth. (C) 2008 Elsevier B.V. All rights reserved.
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| 6. |
- Borg, Mattias, et al.
(author)
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GaAs/GaSb nanowire heterostructures grown by MOVPE
- 2008
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In: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248. ; 310:18, s. 4115-4121
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Journal article (peer-reviewed)abstract
- We report Au-assisted growth of GaAs/GaSb nanowire heterostructures on GaAs(1 1 1)B-substrates by metal-organic vapor phase epitaxy. The growth is studied at various precursor molar fractions and temperatures, in order to optimize the growth conditions for the GaSb nanowire segment. In contrast to most other III-V nanowire systems, the GaSb nanowire growth is Group V-limited under most conditions. We found that depending on the TMSb molar fraction, the seed particle is either supersaturated AuGa or AuGa2 during GaSb growth. The high Ga content in the particle gives a characteristic diameter increase between the GaAs and GaSb segment. From TEM and XEDS measurements we conclude that the GaSb nanowire growth occurs along either the AuGa-GaSb or AuGa2-GaSb pseudo-binaries of the Au-Ga-Sb ternary phase diagram. Finally, the GaSb nanowires exhibit untapered radial growth on the {1 (1) over bar 0} side facets. (C) 2008 Elsevier B.V. All rights reserved.
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| 8. |
- Delorme, Richard, et al.
(author)
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No human tryptophan hydroxylase-2 gene R441H mutation in a large cohort of psychiatric patients and control subjects.
- 2006
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In: Biological Psychiatry. - : Elsevier BV. - 0006-3223. ; 60:2, s. 202-203
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Journal article (peer-reviewed)abstract
- BACKGROUND: It was recently reported that a rare functional variant, R441H, in the human tryptophan hydroxylase-2 gene (hTPH2) could represent an important risk factor for unipolar major depression (UP) since it was originally found in 10% of UP patients (vs. 1.4% in control subjects). METHODS: We explored the occurrence of this variation in patients with affective disorders (n = 646), autism spectrum disorders (n = 224), and obsessive-compulsive disorder (OCD) (n = 201); in healthy volunteers with no psychiatric disorders (n = 246); and in an ethnic panel of control individuals from North Africa, Sub-Saharan Africa, India, China, and Sweden (n = 277). RESULTS: Surprisingly, we did not observe the R441H variant in any of the individuals screened (3188 independent chromosomes). CONCLUSIONS: Our results do not confirm the role of the R441H mutation of the hTPH2 gene in the susceptibility to UP. The absence of the variant from a large cohort of psychiatric patients and control subjects suggests that the findings reported in the original study could be due to a genotyping error or to stratification of the initial population reported. Additional data by other groups should contribute to the clarification of the discrepancy between our results and those previous published.
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| 9. |
- Hägglund, Gunnar, et al.
(author)
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Development of spasticity with age in a total population of children with cerebral palsy
- 2008
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In: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 9
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Journal article (peer-reviewed)abstract
- Background: The development of spasticity with age in children with cerebral palsy (CP) has, to our knowledge, not been studied before. In 1994, a register and a health care program for children with CP in southern Sweden were initiated. In the programme the child's muscle tone according to the modified Ashworth scale is measured twice a year until six years of age, then once a year. We have used this data to analyse the development of spasticity with age in a total population of children with cerebral palsy. Methods: All measurements of muscle tone in the gastrocnemius-soleus muscle in all children with CP from 0 to 15 years during the period 1995-2006 were analysed. The CP subtypes were classified according to the Surveillance of Cerebral Palsy in Europe network system. Using these criteria, the study was based on 6218 examinations in 547 children. For the statistical analysis the Ashworth scale was dichotomized. The levels 0-1 were gathered in one category and levels 2-4 in the other. The pattern of development with age was evaluated using piecewise logistic regression in combination with Akaike's An Information Criterion. Results: In the total sample the degree of muscle tone increased up to 4 years of age. After 4 years of age the muscle tone decreased each year up to 12 years of age. A similar development was seen when excluding the children operated with selective dorsal rhizotomy, intrathecal baclofen pump or tendo Achilles lengthening. At 4 years of age about 47% of the children had spasticity in their gastro-soleus muscle graded as Ashworth 2-4. After 12 years of age 23% of the children had that level of spasticity. The CP subtypes spastic bilateral and spastic unilateral CP showed the same pattern as the total sample. Children with dyskinetic type of CP showed an increasing muscle tone up to age 6, followed by a decreasing pattern up to age 15. Conclusion: In children with CP, the muscle tone as measured with the Ashworth scale increases up to 4 years of age and then decreases up to 12 years of age. The same tendency is seen in all spastic subtypes. The findings may have implications both for clinical judgement and for research studies on spasticity treatment.
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| 10. |
- Nilsson, Henrik, et al.
(author)
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Giant, level-dependent g factors in InSb nanowire quantum dots.
- 2009
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In: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 9:9, s. 3151-3156
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Journal article (peer-reviewed)abstract
- We report on magnetotransport measurements on InSb nanowire quantum dots. The measurements show that the quantum levels of the InSb quantum dots have giant g factors, with absolute values up to approximately 70, the largest value ever reported for semiconductor quantum dots. We also observe that the values of these g factors are quantum level dependent and can differ strongly between different quantum levels. The presence of giant g factors indicates that considerable contributions from the orbital motion of electrons are preserved in the measured InSb nanowire quantum dots, while the level-to-level fluctuations arise from spin-orbit interaction. We have deduced a value of Delta(SO) = 280 mueV for the strength of spin-orbit interaction from an avoided level crossing between the ground state and first excited state of an InSb nanowire quantum dot with a fixed number of electrons.
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