| 1. |
- Carlsson, Sofia, et al.
(författare)
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Genetic effects on physical activity : results from the Swedish Twin Registry
- 2006
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Ingår i: Medicine & Science in Sports & Exercise. - : Ovid Technologies (Wolters Kluwer Health). - 0195-9131 .- 1530-0315. ; 38:8, s. 1396-1401
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of this study was to investigate the genetic effects on leisure-time physical activity using data from the Swedish Twin Registry. METHODS: We investigated 13,362 twin pairs (5334 monozygotic and 8028 dizygotic pairs) aged 14-46 yr. Information on leisure-time physical activity was obtained by questionnaire. Correlations and odds ratios of physical activity were calculated for males, females, and monozygotic and dizygotic twins, respectively. Structural equation modeling was used to estimate the contribution of genetic effects as well as common and nonshared environmental factors on leisure-time physical activity. RESULTS: About one third of the twins reported that they exercised regularly (26% in females and 39% in males). The correlations of physical activity were twice as high in monozygotic compared with dizygotic twins, suggesting the presence of genetic effects. The variation in physical activity due to heritage was 57% (95% confidence interval (CI) = 0.49-0.63) in males and 50% (95% CI = 0.49-0.55) in females. The common environmental influence on physical activity was very small compared with the influence from environmental factors unique to the individual. CONCLUSIONS: Our study establishes heredity as an important component behind individual differences in physical activity in adult men and women. This may be one reason behind difficulties in convincing people to adopt an active lifestyle. Still, this study shows that there is a substantial influence on physical activity from environmental factors unique to the individual.
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| 2. |
- Lindh, Roland, 1958-, et al.
(författare)
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A submatrix algorithm for the matrix-vector multiplication of very large matrices
- 1989
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Ingår i: Journal of Computational Chemistry. - : Wiley. - 0192-8651 .- 1096-987X. ; 10:3, s. 344-345
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Tidskriftsartikel (refereegranskat)abstract
- In self-consistent field (SCF) calculations the construction of the Fock matrix is most time-consuming step. The Fock matrix construction may formally be seen as a matrix-vector multiplication, where the matrix is the supermatrix,��ijkl, and the vector is the first-order density matrix, γij. This formalism should be optimal for vector machines. This is not, however, fully utilized in most programs running on computers with small core memory. The size of the �� matrix, typically in the order of 106–108 elements, has forced programmers to implement other nonvectorizable methods. We will present a submatrixbased algorithm which will partition the supermatrix so that vectorizable methods can be employed. The method will also reduce the input/output.
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| 3. |
- van Ettinger-Veenstra, Helene M, 1982-, et al.
(författare)
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Neuroimaging of decoding and language comprehension in young very low birth weight (VLBW) adolescents : Indications for compensatory mechanisms
- 2017
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Ingår i: PLOS ONE. - San Francisco, United States : Public Library of Science. - 1932-6203. ; 12:10
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Tidskriftsartikel (refereegranskat)abstract
- In preterm children with very low birth weight (VLBW amp;lt;= 1500 g), reading problems are often observed. Reading comprehension is dependent on word decoding and language comprehension. We investigated neural activation-within brain regions important for reading-related to components of reading comprehension in young VLBW adolescents in direct comparison to normal birth weight (NBW) term-born peers, with the use of functional magnetic resonance imaging (fMRI). We hypothesized that the decoding mechanisms will be affected by VLBW, and expect to see increased neural activity for VLBW which may be modulated by task performance and cognitive ability. The study investigated 13 (11 included in fMRI) young adolescents (ages 12 to 14 years) born preterm with VLBW and in 13 NBW controls (ages 12-14 years) for performance on the Block Design and Vocabulary subtests of the Wechsler Intelligence Scale for Children; and for semantic, orthographic, and phonological processing during an fMRI paradigm. The VLBW group showed increased phonological activation in left inferior frontal gyrus, decreased orthographic activation in right supramarginal gyrus, and decreased semantic activation in left inferior frontal gyrus. Block Design was related to altered right-hemispheric activation, and VLBW showed lower WISC Block Design scores. Left angular gyrus showed activation increase specific for VLBW with high accuracy on the semantic test. Young VLBW adolescents showed no accuracy and reaction time performance differences on our fMRI language tasks, but they did exhibit altered neural activation during these tasks. This altered activation for VLBW was observed as increased activation during phonological decoding, and as mainly decreased activation during orthographic and semantic processing. Correlations of neural activation with accuracy on the semantic fMRI task and with decreased WISC Block Design performance were specific for the VLBW group. Together, results suggest compensatory mechanisms by recruiting additional brain regions upon altered neural development of decoding for VLBW.
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| 4. |
- Adolfsson, Jan, et al.
(författare)
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Clinical characteristics and primary treatment of prostate cancer in Sweden between 1996 and 2005 : Data from the national prostate cancer register in Sweden
- 2007
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Ingår i: Scandinavian Journal of Urology and Nephrology. - Stockholm : Taylor & Francis. - 0036-5599 .- 1651-2065. ; 41:6, s. 456-477
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Tidskriftsartikel (refereegranskat)abstract
- Objective. The incidence of prostate cancer is rising rapidly in Sweden and there is a need to better understand the pattern of diagnosis, tumor characteristics and treatment. Material and methods. Between 1996 and 2005, all new cases of adenocarcinoma of the prostate gland were intended to be registered in the National Prostate Cancer Register (NPCR). This register contains information on diagnosing unit, date of diagnosis, cause of diagnosis, tumor grade, tumor stage according to the TNM classification in force, serum prostate-specific antigen (PSA) levels at diagnosis and primary treatment given within the first 6 months after diagnosis. Results. In total, 72 028 patients were registered, comprising >97% of all pertinent incident cases of prostate cancer in the Swedish Cancer Register (SCR). During the study period there was a considerable decrease in median age at the time of diagnosis, a stage migration towards smaller tumors, a decrease in median serum PSA values at diagnosis, a decrease in the age-standardized incidence rate of men diagnosed with distant metastases or with a PSA level of >100 ng/ml at diagnosis and an increase in the proportion of tumors with Gleason score ≤6. Relatively large geographical differences in the median age at diagnosis and the age-standardized incidence of cases with category T1c tumors were observed. Treatment with curative intent increased dramatically and treatment patterns varied according to geographical region. In men with localized tumors and a PSA level of <20 ng/ml at diagnosis, expectant treatment was more commonly used in those aged ≥75 years than in those aged <75 years. Also, the pattern of endocrine treatment varied in different parts of Sweden. Conclusions. All changes in the register seen over time are consistent with increased diagnostic activity, especially PSA testing, resulting in an increased number of cases with early disease, predominantly tumors in category T1c. The patterns of diagnosis and treatment of prostate cancer vary considerably in different parts of Sweden. The NPCR continues to be an important source for research, epidemiological surveillance of the incidence, diagnosis and treatment of prostate cancer
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| 5. |
- Bonk, Fábio A., et al.
(författare)
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Investigation by Combined Solid-State NMR and SAXS Methods of the Morphology and Domain Size in Polystyrene-b-Polyethylene Oxide-b-Polystyrene Triblock Copolymers
- 2010
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Ingår i: Journal of Polymer Science. Part B, Polymer Physics. - : Wiley. - 0887-6266. ; 48:1, s. 55-64
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Tidskriftsartikel (refereegranskat)abstract
- The microphase structure of a series of polystyrene-b-polyethylene oxide-b-polystyrene (SEOS) triblock copolymers with different compositions and molecular weights has been studied by solid-state NMR, DSC, wide and small angle X-ray scattering (WAXS and SAXS). WAXS and DSC measurements were used to detect the presence of crystalline domains of polyethylene-oxide (PEO) blocks at room temperature as a function of the copolymer chemical composition. Furthermore, DSC experiments allowed the determination of the melting temperatures of the crystalline part of the PEO blocks. SAXS measurements, performed above and below the melting temperature of the PEO blocks, revealed the formation of periodic structures, but the absence or the weakness of high order reflections peaks did not allow a clear assessment of the morphological structure of the copolymers. This information was inferred by combining the results obtained by SAXS and 1H NMR spin diffusion experiments, which also provided an estimation of the size of the dispersed phases of the nanostructured copolymers.
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| 6. |
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| 7. |
- Jamid, H. A., et al.
(författare)
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A new higher order finite-difference approximation scheme for the method of lines
- 2001
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Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 0733-8724 .- 1558-2213. ; 19:3, s. 398-404
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Tidskriftsartikel (refereegranskat)abstract
- A new 5-point and a 7-point nonuniform mesh finite-difference scheme is introduced to approximate the second-derivative operator. The scheme is applied using the method of lines. The necessary interface conditions for the TE and TM fields at an index discontinuity are appropriately included in the derivation. This scheme can model lossy dielectrics as well as metallic layers in a unified way. Numerical results are given for the fundamental TE and TM modes of a high-contrast waveguide and for a metal/dielectric single interface TM surface-plasmon mode showing excellent convergence behavior to the analytical results.
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| 8. |
- Vapen, Anna, et al.
(författare)
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2-clickAuth - Optical Challenge-Response Authentication using Mobile Handsets
- 2011
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Ingår i: International Journal on Mobile Computing and Multimedia Communications. - Hershey, USA : IGI Global. - 1937-9412 .- 1937-9404. ; 3:2, s. 1-18
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Tidskriftsartikel (refereegranskat)abstract
- Internet users often have usernames and passwords at multiple web sites. To simplify things, many sites support federated identity management, which enables users to have a single account allowing them to log on to different sites by authenticating to a single identity provider. Most identity providers perform authentication using a username and password. Should these credentials be compromised, all of the user’s accounts become compromised. Therefore a more secure authentication method is desirable. This paper implements 2-clickAuth, a multimedia-based challenge-response solution which uses a web camera and a camera phone for authentication. Two-dimensional barcodes are used for the communication between phone and computer, which allows 2-clickAuth to transfer relatively large amounts of data in a short period of time. 2-clickAuth is more secure than passwords while easy to use and distribute. 2-clickAuth is a viable alternative to passwords in systems where enhanced security is desired, but availability, ease-of-use, and cost cannot be compromised. This paper implements an identity provider in the OpenID federated identity management system that uses 2-clickAuth for authentication, making 2-clickAuth available to all users of sites that support OpenID, including Facebook, Sourceforge, and MySpace.
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| 9. |
- Bratt, Mattias, et al.
(författare)
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Design of a Control Strategy for Teleoperation of a Platform with Significant Dynamics
- 2006
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Ingår i: 2006 IEEE/RSJ International Conference on Intelligent Robots and Systems, Vols 1-12. - NEW YORK, NY : IEEE. - 9781424402588 ; , s. 1700-1705
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Konferensbidrag (refereegranskat)abstract
- A teleoperation system for controlling a robot with fast dynamics over the Internet has been constructed. It employs a predictive control structure with an accurate dynamic model of the robot to overcome problems caused by varying delays. The operator interface uses a stereo virtual reality display of the robot cell, and a haptic device for force feed-back including virtual obstacle avoidance forces.
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| 10. |
- Allen, Matthew S., et al.
(författare)
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Weakly nonlinear systems: Modeling and experimental methods
- 2020
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Ingår i: CISM International Centre for Mechanical Sciences, Courses and Lectures. - Cham : Springer International Publishing. - 2309-3706 .- 0254-1971. ; 594, s. 269-277
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The prior chapter presented rigorous theory and methods for nonlinear systems, which is necessary in general because many nonlinear systems exhibit strong modal coupling due to the nonlinearity; this is commonly the case for the geometrically nonlinear structures that were the focus of that chapter. However, one of the most common sources of nonlinearity in built-up structures is the joints, and in many cases, these introduce only a weak stiffness nonlinearity together with a significant damping nonlinearity. In this case, and in many others that are relevant to industry, one can obtain good estimates of the response of the structure using a weakly nonlinear model in which the linear modes of the structure are presumed to be preserved and coupling between modes is neglected. This chapter provides a brief introduction to these concepts.—Chapter Authors: Randall Mayes and Matt Allen.
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