| 1. |
- Poutanen, Markku, et al.
(author)
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DynaQlim – Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas
- 2010
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In: New Frontiers in Integrated Solid Earth Sciences. - Dordrecht : Springer. - 9789048127368 - 9789048127375 ; , s. 349-372
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Book chapter (other academic/artistic)abstract
- The isostatic adjustment of the solid Earth to the glacial loading (GIA, Glacial Isostatic Adjustment) with its temporal signature offers a great opportunity to retrieve information of Earth’s upper mantle to the changing mass of glaciers and ice sheets, which in turn is driven by variations in Quaternary climate. DynaQlim (Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas) has its focus to study the relations between upper mantle dynamics, its composition and physical properties, temperature, rheology, and Quaternary climate. Its regional focus lies on the cratonic areas of northern Canada and Scandinavia.Geodetic methods like repeated precise levelling, tide gauges, high-resolution observations of recent movements, gravity change and monitoring of postglacial faults have given information on the GIA process for more than 100 years. They are accompanied by more recent techniques like GPS observations and the GRACE and GOCE satellite missions which provide additional global and regional constraints on the gravity field. Combining geodetic observations with seismological investigations, studies of the postglacial faults and continuum mechanical modelling of GIA, DynaQlim offers new insights into properties of the lithosphere. Another step toward a better understanding of GIA has been the joint inversion of different types of observational data – preferentially connected with geological relative sea-level evidence of the Earth’s rebound during the last 10,000 years.Due to the changes in the lithospheric stress state large faults ruptured violently at the end of the last glaciation in large earthquakes, up to the magnitudes MW = 7–8. Whether the rebound stress is still able to trigger a significant fraction of intraplate seismic events in these regions is not completely understood due to the complexity and spatial heterogeneity of the regional stress field. Understanding of this mechanism is of societal importance.Glacial ice sheet dynamics are constrained by the coupled process of the deformation of the viscoelastic solid Earth, the ocean and climate variability. Exactly how the climate and oceans reorganize to sustain growth of ice sheets that ground to continents and shallow continental shelves is poorly understood. Incorporation of nonlinear feedback in modelling both ocean heat transport systems and atmospheric CO2 is a major challenge. Climate-related loading cycles and episodes are expected to be important, hence also more short-term features of palaeoclimate should be explicitly treated.Within this Chapter View ChapterIntroductionObservational BasisCurrent Models and Problems to be SolvedClimateChallenges with DynaQlimReferencesReferencesOther actionsExport citationsAbout this BookReprints and Permissions
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| 2. |
- Frisvad, Jeppe Revall, et al.
(author)
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Survey of Models for Acquiring the Optical Properties of Translucent Materials
- 2020
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In: Computer graphics forum (Print). - : Wiley. - 0167-7055 .- 1467-8659. ; 39, s. 729-755
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Journal article (peer-reviewed)abstract
- The outset of realistic rendering is a desire to reproduce the appearance of the real world. Rendering techniques therefore operate at a scale corresponding to the size of objects that we observe with our naked eyes. At the same time, rendering techniques must be able to deal with objects of nearly arbitrary shapes and materials. These requirements lead to techniques that oftentimes leave the task of setting the optical properties of the materials to the user. Matching the appearance of real objects by manual adjustment of optical properties is however nearly impossible. We can render objects with a plausible appearance in this way but cannot compare the appearance of a manufactured item to that of its digital twin. This is especially true in the case of translucent objects, where we need more than a goniometric measurement of the optical properties. In this survey, we provide an overview of forward and inverse models for acquiring the optical properties of translucent materials. We map out the efforts in graphics research in this area and describe techniques available in related fields. Our objective is to provide a better understanding of the tools currently available for appearance specification when it comes to digital representations of real translucent objects.
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| 3. |
- Gregersen, Søren, et al.
(author)
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Seismicity and sources of stress in Fennoscandia
- 2021
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In: Glacially-Triggered Faulting. - Cambridge : Cambridge University Press. - 9781108779906 - 9781108490023 ; , s. 177-197
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Book chapter (peer-reviewed)abstract
- This chapter investigates the Fennoscandian uplift area since the latest Ice Age and addresses the question if glacial isostatic adjustment may influence current seismicity. The region is in an intraplate area, with stresses caused by the lithospheric relative plate motions. Discussions on whether uplift and plate tectonics are the only causes of stress have been going on for many years in the scientific community.This review considers the improved sensitivity of the seismograph networks, and at the same time attempts to omit man-made explosions and mining events in the pattern, to present the best possible earthquake pattern. Stress orientations and their connection to the uplift pattern and known tectonics are evaluated. Besides plate motion and uplift, one finds that some regions are affected stress-wise by differences in geographical sediment loading as well as by topography variations. The stress release in the present-day earthquakes shows a pattern that deviates from that of the time right after the Ice Age. This chapter treats the stress pattern generalized for Fennoscandia and guides the interested reader to more details in the national chapters.
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| 4. |
- Jendle, Johan, 1963-, et al.
(author)
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Late-onset familial neurohypophyseal diabetes insipidus due to a novel mutation in the AVP gene
- 2012
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In: Clinical Endocrinology. - Hoboken, USA : Wiley-Blackwell. - 0300-0664 .- 1365-2265. ; 77:4, s. 586-592
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Journal article (peer-reviewed)abstract
- Objective: Familial neurohypophyseal diabetes insipidus (FNDI) is mainly an autosomal dominant inherited disorder presenting with severe polydipsia and polyuria in early childhood. In this study, we aimed to determine the molecular genetics and clinical characteristics of a large Swedish-Norwegian family presenting with very late-onset autosomal dominant FNDI.Patients: Six probands with a history of developing polyuria and polydipsia during adolescence were studied.Measurements: Information on family demography was collected by personal interview with family members. The genetic cause of FNDI was identified by DNA sequencing analysis of the coding regions of the AVP gene. The clinical characteristics were determined by the measurement of basal urine production and osmolality as well as by measurements of concurrent levels of plasma AVP, plasma osmolality, and urine osmolality during fluid deprivation and bolus injection of DDAVP. The integrity of the neurohypophysis was evaluated by magnetic resonance imaging.Results: The mean age of encountering the first clinical symptoms in the family was 14·8 years (range 3-30 years) (n = 17). All six affected subjects investigated were heterozygous for a novel mutation in the AVP gene (g.1848C>T) predicting a p.Pro84Leu substitution in the AVP precursor protein. We found partial deficiency in evoked AVP secretion during fluid deprivation in one subject and complete deficiency in another. The pituitary bright spot was absent in all six affected subjects studied.Conclusion: A novel mutation in the AVP gene predicted to cause a neurophysin II dimerization defect is causing surprisingly late onset of FNDI in a large, six generation, Swedish-Norwegian family. The mutation is associated with both complete and partial deficiency in evoked AVP secretion during fluid deprivation in patients who have suffered from FNDI for decades.
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| 5. |
- Rakvaag, Elin, et al.
(author)
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Whey Protein Combined with Low Dietary Fiber Improves Lipid Profile in Subjects with Abdominal Obesity: A Randomized, Controlled Trial
- 2019
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In: Nutrients. - : MDPI AG. - 2072-6643 .- 2072-6643. ; 11:9
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Journal article (peer-reviewed)abstract
- Abdominal obesity is associated with elevated postprandial triglycerides (TG), an independent risk factor for cardiovascular diseases. Previous studies show that whey protein (WP) and dietary fiber may separately reduce postprandial TG. However, few studies have investigated the long-term effects of WP and dietary fiber on postprandial TG. We aimed to investigate the separate and combined long-term effects of WP and dietary fiber from wheat bran on postprandial TG and markers of lipid metabolism in subjects with abdominal obesity. We conducted a 12-week, double-blind, randomized, controlled, parallel intervention study. In a 2 × 2 factorial design, 73 adults were randomized to receive 60 g/day of either WP hydrolysate or maltodextrin (MD) combined with high-fiber wheat bran products (HiFi; 30 g dietary fiber/day) or low-fiber refined wheat products (LoFi; 10 g dietary fiber/day). A high-fat meal test was conducted before and after the intervention. Sixty-five subjects were included in the final analyses. There were no differences between intervention groups in postprandial TG assessed as incremental area under the curve (iAUC). WP-LoFi had reduced postprandial TG assessed as total area under the curve (tAUC) and reduced fasting TG compared with all other groups, and reduced fasting apolipoprotein B-48 compared with MD-LoFi. There were no changes in lipoprotein lipase activity. Total cholesterol and apolipoprotein B-100 were reduced after WP intake compared with MD. Total cholesterol was increased after HiFi intake compared with LoFi. In conclusion, intake of WP in combination with low-fiber cereal products for 12 weeks had beneficial effects on postprandial TG tAUC and fasting TG, but not on postprandial TG iAUC in subjects with abdominal obesity. Combining WP with high-fiber wheat bran products did not improve lipid profile.
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| 6. |
- Yan, Xin, et al.
(author)
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Differential Impact of Glucose Administered Intravenously and Orally on Circulating miR-375 Levels in Human Subjects
- 2017
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In: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 102:10, s. 3749-3755
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Journal article (peer-reviewed)abstract
- BackgroundTo date, numerous nucleic acid species have been detected in the systemic circulation including microRNAs (miRNAs); however, their functional role in this compartment remains unclear.ObjectiveThe aim of this study was to determine whether systemic levels of miRNAs abundant in blood, including the neuroendocrine tissue-enriched miR-375, are altered in response to a glucose challenge.DesignTwelve healthy males were recruited for an acute crossover study that consisted of two tests each following an 8-hour fasting period. An oral glucose tolerance test (OGTT) was performed, and blood samples were collected over a 3-hour period. Following a period of at least 1 week, the same participants were administered an isoglycemic intravenous glucose infusion (IIGI) with the same blood-collection protocol.ResultsThe glucose response curve following the IIGI mimicked that obtained after the OGTT, but as expected, systemic insulin levels were lower during the IIGI compared with the OGTT (P < 0.05). miR-375 levels in circulation were increased only in response to an OGTT and not during an IIGI. In addition, the response to the OGTT also coincided with the transient increase of circulating glucagon-like peptide (GLP)-1, GLP-2, and glucose-dependent insulinotropic polypeptide.ConclusionsThe present findings show levels of miR-375 increase following administration of an OGTT and, in light of its enrichment in cells of the gut, suggest that the gastrointestinal tract may play an important role in the abundance and function of this miRNA in the blood.
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