| 1. |
- Ljung, Patric, 1968-, et al.
(författare)
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Forensic Virtual Autopsies by Direct Volume Rendering
- 2007
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Ingår i: IEEE signal processing magazine (Print). - Piscataway, NJ, USA : IEEE. - 1053-5888 .- 1558-0792. ; 24:6, s. 112-116
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents state-of-the-art methods, which address the technical challenges in visualizing large three-dimensional (3D) data and enable rendering at interactive frame rates.
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| 2. |
- Lundin (Palmerius), Karljohan, 1977-, et al.
(författare)
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Enabling design and interactive selection of haptic modes
- 2007
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Ingår i: Virtual Reality. - : Springer Science and Business Media LLC. - 1359-4338 .- 1434-9957.
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Tidskriftsartikel (refereegranskat)abstract
- The ever increasing size and complexity of volumetric data in a wide range of disciplines makes it useful to augment volume visualization tools with alternative modalities. Studies have shown that introducing haptics can significantly increase both exploration speed and precision. It is also capable of conveying material properties of data and thus has great potential to improve user performance in volume data exploration. In this paper we describe how recent advances in volume haptics can be used to build haptic modes-building blocks for haptic schemes. These modes have been used as base components of a toolkit allowing for more efficient development of haptic prototypes and applications. This toolkit allows interactive construction, configuration and fine-tuning of both visual and haptic representations of the data. The technology is also used in a pilot study to determine the most important issues and aspects in haptic volume data interaction and exploration, and how the use of haptic modes can facilitate the implementation of effective haptic schemes.
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| 3. |
- Lundström, Claes, 1973-, et al.
(författare)
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Uncertainty Visualization in Medical Volume Rendering Using Probabilistic Animation
- 2007
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Ingår i: IEEE Transactions on Visualization and Computer Graphics. - 1077-2626 .- 1941-0506. ; 13:6, s. 1648-1655
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Tidskriftsartikel (refereegranskat)abstract
- Direct volume rendering has proved to be an effective visualization method for medical data sets and has reached wide-spread clinical use. The diagnostic exploration, in essence, corresponds to a tissue classification task, which is often complex and time-consuming. Moreover, a major problem is the lack of information on the uncertainty of the classification, which can have dramatic consequences for the diagnosis. In this paper this problem is addressed by proposing animation methods to convey uncertainty in the rendering. The foundation is a probabilistic Transfer Function model which allows for direct user interaction with the classification. The rendering is animated by sampling the probability domain over time, which results in varying appearance for uncertain regions. A particularly promising application of this technique is a "sensitivity lens" applied to focus regions in the data set. The methods have been evaluated by radiologists in a study simulating the clinical task of stenosis assessment, in which the animation technique is shown to outperform traditional rendering in terms of assessment accuracy.
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| 4. |
- Nilsson, Anders, et al.
(författare)
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Behavioral interference and facilitation in the foraging cycle shape the functional response
- 2007
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Ingår i: Behavioral Ecology. - : Oxford University Press (OUP). - 1045-2249 .- 1465-7279. ; 18:2, s. 354-357
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Tidskriftsartikel (refereegranskat)abstract
- Individual forager behaviors should affect per capita intake rates and thereby population and consumer-resource properties. We consider and incorporate conspecific facilitation and interference during the separate foraging-cycle stages in a functional response model that links individual behavioral interactions with consumer-resource processes. Our analyses suggest that failing to properly consider and include all effects of behavioral interactions on foraging-cycle stage performances may either over- or underestimate effects of interactions on the shape of both functional responses and predator zero-growth isoclines. Incorporation of prey- and predator-dependent interactions among foragers in the model produces predator isoclines with potentials for highly complex consumer-resource dynamics. Facilitation and interference during the foraging cycle are therefore suggested as potent behavioral mechanisms to cause patterns of community dynamics. We emphasize that correct estimations of interaction-mediated foraging-cycle efficiencies should be considered in empirical and theoretical attempts to further our understanding of the mechanistic link between social behaviors and higher order processes.
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| 5. |
- Olofsson, Anders, et al.
(författare)
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Amide solvent protection analysis demonstrates that amyloid-beta(1-40) and amyloid-beta(1-42) form different fibrillar structures under identical conditions.
- 2007
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Ingår i: Biochem J. - 1470-8728. ; 404:1, s. 63-70
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Tidskriftsartikel (refereegranskat)abstract
- AD (Alzheimer's disease) is a neurodegenerative disorder characterized by self-assembly and amyloid formation of the 39–43 residue long Ab (amyloid-b)-peptide. The most abundant species, Ab(1–40) and Ab(1–42), are both present within senile plaques, but Ab(1–42) peptides are considerably more prone to self-aggregation and are also essential for the development of AD. To understand the molecular and pathological mechanisms behind AD, a detailed knowledge of the amyloid structures of Ab-peptides is vital. In the present study we have used quenched hydrogen/deuterium-exchange NMR experiments to probe the structure of Ab(1–40) fibrils. The fibrils were prepared and analysed identically as in our previous study on Ab(1–42) fibrils, allowing a direct comparison of the two fibrillar structures. The solvent protection pattern of Ab(1–40) fibrils revealed two well-protected regions, consistent with a structural arrangement of two b-strands connected with a bend. This protection pattern partly resembles the pattern found in Ab(1–42) fibrils, but the Ab(1–40) fibrils display a significantly increased protection for the N-terminal residues Phe4–His14, suggesting that additional secondary structure is formed in this region. In contrast, the C-terminal residues Gly37–Val40 show a reduced protection that suggests a loss of secondary structure in this region and an altered filament assembly. The differences between the present study and other similar investigations suggest that subtle variations in fibril-preparation conditions may significantly affect the fibrillar architecture.
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| 6. |
- Andersson, Eva, 1955, et al.
(författare)
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Cohort mortality study of Swedish pulp and paper mill workers-nonmalignant diseases
- 2007
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Ingår i: Scandinavian Journal of Work, Environment and Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 33:6, s. 470-478
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Tidskriftsartikel (refereegranskat)abstract
- Objectives The aim of this study was to determine mortality among pulp and paper mill workers according to the main mill pulping process, department, and gender, particular reference being given to diseases of the circulatory and respiratory systems.Methods The cohort of 18 163 men and 2 291 women employed between 1939 and 1999 and with >1 year of employment was followed for mortality from 1952 to 2001 (acute myocardial infarction from 1969). Standardized mortality ratios (SMR) with 95% confidence intervals (95% CI) were estimated by comparing the observed number of deaths with the expected number for the entire Swedish population. Exposure was assessed from personnel files in the mills. Data from an exposure measurement database are also presented.Results There were 5898 deaths in the cohort. Total mortality had an SMR of 1.02 (95% CI 0.98–1.06) for the men in the sulfate mills and an SMR of 0.93 (95% CI 0.90–0.97) for the men in the sulfite mills. Mortality from acute myocardial infarction was increased among the men in both the sulfate and sulfite mills [SMR 1.22 (95% CI 1.12–1.32) and SMR 1.11 (95% CI 1.02–1.21), respectively] and by department in sulfate pulping (SMR 1.29, 95% CI 1.07–1.54), paper production (SMR 1.26, 95% CI 1.06–1.49), and maintenance (SMR 1.16, 95% CI 1.02–1.30). Mortality from cerebrovascular disease, diabetes mellitus, and nonmalignant respiratory diseases was not increased.Conclusions Death from acute myocardial infarction, but not cerebrovascular diseases, was increased in this cohort and was probably related to a combination of different occupational exposures (eg, dust, sulfur compounds, shift work, and noise).
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| 7. |
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| 8. |
- Axelsson, Karin, 1968-, et al.
(författare)
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Communication Analysis of Public Forms : Discovering Multi-functional Purposes in Citizen and Government Communication
- 2007
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Ingår i: International Journal of Public Information Systems. - Sundsvall : MidSweden University. - 1653-4360. ; :3, s. 161-181
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Tidskriftsartikel (refereegranskat)abstract
- This paper adopts a communication perspective on forms in public e-services. This perspective emphasizes that the main purpose of such forms is to facilitate communication between citizens and government agencies. The form is perceived as a tool for performing communicative actions. A communication analysis (CA) method, originally developed for systems requirements engineering, is applied on a public form; i.e. the medical certificate used in connection with a citizen’s application for a provisional driving license in Sweden. The CA method consists of a set of questions related tothree communicative categories; conditions, actions, and consequences. The CA method is used in order to explore the communicative roles of forms in public e-services. As a result of the communication analysis four multi-functional purposes of citizen and government agency communication are discovered. These purposes contribute to the understanding and evaluation of forms in public e-services. The communicative roles, and their multi-functional purposes, are important design features to focus in the development of e-services and electronic forms. Besides these findings, another outcomeis that the CA method has been tested in an e-government context. The communication perspective, as well as the CA method, contribute with useful insights in this context.
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| 9. |
- Bivall Persson, Petter, 1979-, et al.
(författare)
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Designing and Evaluating a Haptic System for Biomolecular Education
- 2007
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Ingår i: IEEE Virtual Reality Conference, 2007. VR '07.. - Piscataway, NJ, USA : IEEE. - 1424409063 ; , s. 171-178
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Konferensbidrag (refereegranskat)abstract
- In this paper we present an in situ evaluation of a haptic system, with a representative test population, we aim to determine what, if any, benefit haptics can have in a biomolecular education context. We have developed a haptic application for conveying concepts of molecular interactions, specifically in protein-ligand docking. Utilizing a semi-immersive environment with stereo graphics, users are able to manipulate the ligand and feel its interactions in the docking process. The evaluation used cognitive knowledge tests and interviews focused on learning gains. Compared with using time efficiency as the single quality measure this gives a better indication of a system's applicability in an educational environment. Surveys were used to gather opinions and suggestions for improvements. Students do gain from using the application in the learning process but the learning appears to be independent of the addition of haptic feedback. However the addition of force feedback did decrease time requirements and improved the students understanding of the docking process in terms of the forces involved, as is apparent from the students' descriptions of the experience. The students also indicated a number of features which could be improved in future development.
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| 10. |
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