| 3551. |
- Åberg, Sofia, et al.
(författare)
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An image warping approach to spatio-temporal modelling
- 2005
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Ingår i: Environmetrics. - : Wiley. - 1099-095X .- 1180-4009. ; 16:8, s. 833-848
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Tidskriftsartikel (refereegranskat)abstract
- In this article we present a spatio-temporal dynamic model that can be realized using image warping. Image warping is a non-linear deformation which maps every point in one image plane to a point in another image plane. Using thin-plate splines, these deformations are defined by how a small set of points is mapped, making the method computationally tractable. In our case the dynamics of the process is modelled by thin-plate spline deformations and how they vary in time. Thus we make no assumption of stationarity in time. Finding the deformation between two images in the space-time series is a trade-off between a good match of the images and, a smooth, physically plausible, deformation. This is formulated as a penalized likelihood problem, where the likelihood measures how good the match is and the penalty comes from a prior model on the deformation. The dynamic model we suggest can be used to make forecasts and also to estimate the uncertainties associated with these. An introduction to image warping and thin-plate splines is given as well as an application where the methodology is applied to the problem of nowcasting radar precipitation.
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| 3552. |
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| 3553. |
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| 3554. |
- Ågård, Anders, et al.
(författare)
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Experiences and concerns among patients being treated for atypical chest pain.
- 2005
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Ingår i: European Journal of Internal Medicine. - : Elsevier BV. - 1879-0828 .- 0953-6205. ; 16:5, s. 44-339
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Tidskriftsartikel (refereegranskat)abstract
- Background Many patients who are discharged from the hospital without receiving a clear-cut diagnosis of their chest pain continue to consume health care because of disabling physical and psychological symptoms. By identifying their experiences and concerns following hospitalization, an empirical basis for discussions on ways of improving the care of these particular patients will be obtained. Methods A qualitative analysis of semi-structured interviews with 38 patients with a diagnosis of unspecified chest pain was carried out. Results Two-thirds of the respondents had unanswered questions and concerns that had not been addressed. They found it difficult to understand why they had not undergone more tests. They requested an explanation for their chest pain, at the very least, or were worried about the future. Some respondents accepted the fact that they had not been given a sufficient amount of time and information. They referred to the stressful working situation of the physicians, the view that their admission could be regarded as unnecessary or that physicians at the hospital could not be expected to do more than exclude serious diseases. Conclusions Health professionals should address their patients' questions and fears properly and provide them with the most probable explanation for their symptoms. When taking the harmlessness of their symptoms or the situation of their caregivers into account, patients may find it inappropriate to impose further demands on care.
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| 3555. |
- Ågård, Anders, et al.
(författare)
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Familial hypercholesterolemia: ethical, practical and psychological problems from the perspective of patients.
- 2005
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Ingår i: Patient Education and Counseling. - : Elsevier BV. - 0738-3991. ; 57:2, s. 162-167
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Tidskriftsartikel (refereegranskat)abstract
- The main aim of the study was to explore the extent to which familial hypercholesterolemia (FH) influences the life of the patients affected. The study employed a qualitative analysis of semi-structured interviews with 23 outpatients who were being treated following a diagnosis of heterozygous FH at a tertiary hospital in Göteborg, Sweden. Some interviewees reported concerns related to their medication and feelings of guilt when not complying with treatment recommendations. However, none of the respondents expressed sustained emotional distress or would have preferred to be ignorant of their diagnosis. Apart from being more observant about food intake, their awareness of FH did not appear to have had a substantial impact on their way of life. In fact, those who did not suffer from any other diseases generally regarded themselves as healthy. Discussing the genetic constitution with family members with whom they had close contact was natural, but informing distant family members was not.
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| 3556. |
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| 3557. |
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| 3558. |
- Åkesson, Lina, et al.
(författare)
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VPAC2-R Mediates the Lipolytic Effects of Pituitary Adenylate Cyclase-Activating Polypeptide/Vasoactive Intestinal Polypeptide in Primary Rat Adipocytes.
- 2005
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 146:2, s. 744-750
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Tidskriftsartikel (refereegranskat)abstract
- The neuropeptides pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) are structurally and functionally related. Their actions have been shown to be mediated by three different receptor subtypes: PAC1-R, which has exclusive affinity for PACAP, and VPAC1-R and VPAC2-R, which have equal affinity for PACAP and VIP. We recently showed that PACAP38 induces lipolysis in rat adipocytes, and in the present study we examined whether VIP has similar effects and which of the three receptors mediates this PACAP/VIP action. We showed by RT-PCR that all three receptor subtypes are present in rat adipocytes. We demonstrated that VIP (1-100 nM), like PACAP38, stimulates lipolysis in isolated adipocytes, as determined by glycerol release. By a pharmacological approach, using antagonists and agonists specific for the receptor subtypes, we elucidated the mechanisms by which PACAP38 and VIP mediate their lipolytic effects. We found that antagonists of PAC1-R [PACAP(6-38)] and VPAC1-R (PG97-269) did not affect lipolysis induced by 0.1-100 nM PACAP38 or VIP, and that a VPAC1-R agonist [K15, R16, L27VIP(1-7) GRF(8-27)] did not affect lipolysis at 1-1000 nM. However, two different VPAC2-R agonists [Hexa-VIP(1-28) and Ro25-1553] clearly mimicked the lipolytic effect of PACAP38 and VIP. In addition, the VPAC2-R antagonist PG99-465 (100 nM) caused right-shifted dose-response curves of PACAP38- and VIP-induced lipolysis. These results therefore provide evidence that all three PACAP/VIP receptor subtypes are expressed in primary rat adipocytes, but that the VPAC2-R subtype is responsible for mediating the lipolytic effects induced by PACAP38 and VIP.
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| 3559. |
- Åkesson, Susanne, et al.
(författare)
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Dramatic orientation shift of white-crowned sparrows displaced across longitudes in the high arctic
- 2005
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Ingår i: Current Biology. - : Elsevier BV. - 1879-0445 .- 0960-9822. ; 15:17, s. 1591-1597
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Tidskriftsartikel (refereegranskat)abstract
- Advanced spatial-learning adaptations have been shown for migratory songbirds (1], but it is not well known how the simple genetic program encoding migratory distance and direction in young birds [2-4] translates to a navigation mechanism used by adults [2, 4-6]. A number of convenient cues are available to define latitude on the basis of geomagnetic and celestial information [7-15], but very few are useful to defining longitude [12-15]. To investigate the effects of displacements across longitudes on orientation, we recorded orientation of adult and juvenile migratory white-crowned sparrows, Zonotrichia leucophrys gambelii, after passive longitudinal displacements, by ship, of 266-2862 km across high-arctic North America. After eastward displacement to the magnetic North Pole and then across the 0 degrees declination line, adults and juveniles abruptly shifted their orientation from the migratory direction to a direction that would lead back to the breeding area or to the normal migratory route, suggesting that the birds began compensating for the displacement by using geomagnetic cues alone or together with solar cues. In contrast to predictions by a simple genetic migration program, our experiments suggest that both adults and juveniles possess a navigation system based on a combination of celestial and geomagnetic information, possibly declination, to correct for eastward longitudinal displacements.
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| 3560. |
- Årzén, Karl-Erik, et al.
(författare)
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Laboratories and Real-Time Computing
- 2005
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Ingår i: Control Systems Magazine. - 0272-1708. ; 25:1, s. 30-34
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Tidskriftsartikel (refereegranskat)abstract
- The paper describes the approach used at the Department of Automatic Control at Lund Institute of Technology to maintain a high level of practical laboratory experiments. The Department integrates laboratory experiments into its control courses. If the laboratory exercises are properly organized and the student volume is sufficiently large, it is possible to combine a high level of practical laboratory experiments in control education at a reasonable cost. The use of off-the-shelf hardware and open-source software are important, With desktop processes, it is possible to achieve high utilization of lab space and high student throughput.
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