| 1681. |
- Kristensen, Fredrik, et al.
(författare)
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Reduced transceiver-delay for OFDM systems
- 2004
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Ingår i: 2004 IEEE 59th Vehicular Technology Conference. VTC 2004-Spring. - 0780382552 ; , s. 1242-1245
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Konferensbidrag (refereegranskat)abstract
- In this paper, it is shown that more than half of the data flow buffer, due to a bit reversed FFT output and cyclic prefix in an OFDM transceiver, can be removed. To achieve this, a new pipelined FFT processor is proposed and a cyclic suffix is used instead of the more commonly used cyclic prefix. The FFT processor is used either with a forward or backward data flow, i.e. performing either a decimation in time or a decimation in frequency FFT. However, this approach precludes wordlength optimization in the processor and therefore a semi floating-point arithmetic is used to achieve high signal-to-noise ratio. Total delay through the transceiver is reduced by 25% and for larger transceivers silicon area is reduced by as much as 25%. In addition, the proposed scheme reduces the required amount of memory accesses to insert a cyclic extension, and has the basic properties of a simple interleaver
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| 1682. |
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| 1683. |
- Kroeger, Janine, et al.
(författare)
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Adherence to predefined dietary patterns and incident type 2 diabetes in European populations: EPIC-InterAct Study
- 2014
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 57:2, s. 321-333
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Tidskriftsartikel (refereegranskat)abstract
- Few studies have investigated the relationship between predefined dietary patterns and type 2 diabetes incidence; little is known about the generalisability of these associations. We aimed to assess the association between predefined dietary patterns and type 2 diabetes risk in European populations. From among a case-cohort of 12,403 incident diabetes cases and 16,154 subcohort members nested within the prospective European Prospective Investigation into Cancer and Nutrition study, we used data on 9,682 cases and 12,595 subcohort participants from seven countries. Habitual dietary intake was assessed at baseline with country-specific dietary questionnaires. Two diet-quality scores (alternative Healthy Eating Index [aHEI], Dietary Approaches to Stop Hypertension [DASH] score) and three reduced rank regression (RRR)-derived dietary-pattern scores were constructed. Country-specific HRs were calculated and combined using a random-effects meta-analysis. After multivariable adjustment, including body size, the aHEI and DASH scores were not significantly associated with diabetes, although for the aHEI there was a tendency towards an inverse association in countries with higher mean age. We observed inverse associations of the three RRR-derived dietary-pattern scores with diabetes: HRs (95% CIs) for a 1-SD difference were 0.91 (0.86, 0.96), 0.92 (0.84, 1.01) and 0.87 (0.82, 0.92). Random-effects meta-analyses revealed heterogeneity between countries that was explainable by differences in the age of participants or the distribution of dietary intake. Adherence to specific RRR-derived dietary patterns, commonly characterised by high intake of fruits or vegetables and low intake of processed meat, sugar-sweetened beverages and refined grains, may lower type 2 diabetes risk.
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| 1684. |
- Kroeger, Janine, et al.
(författare)
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Circulating Fetuin-A and Risk of Type 2 Diabetes : A Mendelian Randomization Analysis
- 2018
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 67:6, s. 1200-1205
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Tidskriftsartikel (refereegranskat)abstract
- Fetuin-A, a hepatic-origin protein, is strongly positively associated with risk of type 2 diabetes in human observational studies, but it is unknown whether this association is causal. Weaimed to study the potential causal relation of circulating fetuin-A to risk of type 2 diabetes in a Mendelian randomization study with single nucleotide polymorphisms located in the fetuin-A-encoding AHSG gene. We used data from eight European countries of the European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct case-cohort study including 10,020 incident cases. Plasma fetuin-A concentration was measured in a subset of 965 subcohort participants and 654 case subjects. A genetic score of the AHSG single nucleotide polymorphisms was strongly associated with fetuin-A (28% explained variation). Using the genetic score as instrumental variable of fetuin-A, we observed no significant association of a 50 mu g/mL higher fetuin-A concentration with diabetes risk (hazard ratio 1.02 [95% CI 0.97, 1.07]). Combining our results with those from the DIAbetes Genetics Replication And Meta-analysis (DIAGRAM) consortium (12,171 case subjects) also did not suggest a clear significant relation of fetuin-A with diabetes risk. In conclusion, although there is mechanistic evidence for an effect of fetuin-A on insulin sensitivity and secretion, this study does not support a strong, relevant relationship between circulating fetuin-A and diabetes risk in the general population.
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| 1685. |
- Kudahettige, Rasika L., et al.
(författare)
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Characterization of bioethanol production from hexoses and xylose by the white rot fungus trametes versicolor
- 2012
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Ingår i: Bioenergy Research. - : Springer Science and Business Media LLC. - 1939-1234 .- 1939-1242. ; 5:2, s. 277-285
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Tidskriftsartikel (refereegranskat)abstract
- Bioethanol production by white rot fungus (Trametes versicolor), identified from fungal mixture in naturally decomposing wood samples, from hexoses and xylose was characterized. Results showed that T. versicolor can grow in culture, under hypoxic conditions, with various mixtures of hexoses and xylose and only xylose. Xylose was efficiently fermented to ethanol in media containing mixtures of hexoses and xylose, such as MBMC and G11XY11 media (Table 1), yielding ethanol concentrations of 20.0 and 9.02 g/l, respectively, after 354 h of hypoxic culture. Very strong correlations were found between ethanolic fermentation (alcohol dehydrogenase activity and ethanol production), sugar consumption and xylose catabolism (xylose reductase, xylitol dehydrogenase and xylulokinase activities) after 354 h in culture in MBMC medium. In a medium (G11XY11) containing a 1:1 glucose/xylose ratio, fermentation efficiency of total sugars into ethanol was 80% after 354 h.
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| 1686. |
- Kuess, Peter, et al.
(författare)
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Association between pathology and texture features of multi parametric MRI of the prostate
- 2017
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Ingår i: Physics in Medicine and Biology. - : IOP Publishing. - 0031-9155 .- 1361-6560. ; 62:19, s. 7833-7854
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Tidskriftsartikel (refereegranskat)abstract
- The role of multi-parametric (mp)MRI in the diagnosis and treatment of prostate cancer has increased considerably. An alternative to visual inspection of mpMRI is the evaluation using histogram-based (first order statistics) parameters and textural features (second order statistics). The aims of the present work were to investigate the relationship between benign and malignant sub-volumes of the prostate and textures obtained from mpMR images. The performance of tumor prediction was investigated based on the combination of histogram-based and textural parameters. Subsequently, the relative importance of mpMR images was assessed and the benefit of additional imaging analyzed. Finally, sub-structures based on the PI-RADS classification were investigated as potential regions to automatically detect maligned lesions. Twenty-five patients who received mpMRI prior to radical prostatectomy were included in the study. The imaging protocol included T2, DWI, and DCE. Delineation of tumor regions was performed based on pathological information. First and second order statistics were derived from each structure and for all image modalities. The resulting data were processed with multivariate analysis, using PCA (principal component analysis) and OPLS-DA (orthogonal partial least squares discriminant analysis) for separation of malignant and healthy tissue. PCA showed a clear difference between tumor and healthy regions in the peripheral zone for all investigated images. The predictive ability of the OPLS-DA models increased for all image modalities when first and second order statistics were combined. The predictive value reached a plateau after adding ADC and T2, and did not increase further with the addition of other image information. The present study indicates a distinct difference in the signatures between malign and benign prostate tissue. This is an absolute prerequisite for automatic tumor segmentation, but only the first step in that direction. For the specific identified signature, DCE did not add complementary information to T2 and ADC maps.
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| 1687. |
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| 1688. |
- Kulmala, Markku, et al.
(författare)
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Overview of the biosphere-aerosol-cloud-climate interactions (BACCI) studies
- 2008
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Ingår i: Tellus. Series B: Chemical and Physical Meteorology. - : Stockholm University Press. - 0280-6509 .- 1600-0889. ; 60:3, s. 300-317
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Forskningsöversikt (refereegranskat)abstract
- Here we present research methods and results obtained by the Nordic Centre of Excellence Biosphere-Aerosol-Cloud-Climate Interactions (BACCI) between 1 January 2003 and 31 December 2007. The centre formed an integrated attempt to understand multiple, but interlinked, biosphere-atmosphere interactions applying inter and multidisciplinary approaches in a coherent manner. The main objective was to study the life cycle of aerosol particles and their importance on climate change. The foundation in BACCI was a thorough understanding of physical, meteorological, chemical and ecophysiological processes, providing a unique possibility to study biosphere-aerosol-cloud-climate interactions. Continuous measurements of atmospheric concentrations and fluxes of aerosol particles and precursors and, CO2/aerosol trace gas interactions in different field stations (e.g. SMEAR) were supported by models of particle thermodynamics, transport and dynamics, atmospheric chemistry, boundary layer meteorology and forest growth. The main progress was related to atmospheric new particle formation, existence of clusters, composition of nucleation mode aerosol particles, chemical precursors of fresh aerosol particles, the contribution of biogenic aerosol particles on the global aerosol load, transport, transformation and deposition of aerosol particles, thermodynamics related to aerosol particles and cloud droplets, and the microphysics and chemistry of cloud droplet formation.
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| 1689. |
- Kvint, Sven, et al.
(författare)
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Autotransplantation of teeth in 215 patients : A Follow-up Study
- 2010
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Ingår i: Angle orthodontist. - : The Angle Orthodontist (EH Angle Education & Research Foundation). - 0003-3219 .- 1945-7103. ; 80:3, s. 446-451
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To evaluate the success rate of autotransplantation of teeth in consecutive patients and to analyze factors affecting the outcome. Materials andMETHODS: The subjects consisted of 215 consecutive patients (101 women and 114 men; aged 9.1-56.4 years, median age 15.2 years [P(10) = 11.4, P(90) = 19.7]) who had undergone transplantation of a total of 269 teeth, all by the same surgeon. In patients with multiple transplants, only the first transplant was included, to ensure that all transplanted teeth were independent units. The transplants were recorded as unsuccessful if the tooth had been extracted or was surviving but with root resorption or ankylosis. The interval between transplantation and final follow-up was a median 4.8 years (P(10) = 2.0, P(90) = 5.5) for successful transplants and a median of 2.4 years (P(10) = 0.4, P(90) = 7.7) for unsuccessful transplants.RESULTS: One-hundred seventy-five (81%) of the transplantations were recorded as successful and 40 (19%) as unsuccessful. Twenty-five teeth had been extracted and 15 had survived but did not fulfill the criteria for success.CONCLUSIONS: The success rate of 215 consecutively transplanted teeth was 81%. The highest success rate was for transplantation of premolars to the maxillary incisor region (100%). Complications at surgery such as difficult extraction, deviant root anatomy, or damaged root periodontium affected the outcome. During growth, a successful transplant preserves alveolar bone.
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| 1690. |
- Kvist, Ola, et al.
(författare)
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A cross-sectional magnetic resonance imaging study of factors influencing growth plate closure in adolescents and young adults
- 2021
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Ingår i: Acta Paediatrica. - : John Wiley & Sons. - 0803-5253 .- 1651-2227. ; 110:4, s. 1249-1256
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Tidskriftsartikel (refereegranskat)abstract
- Aim To assess growth plate fusion by magnetic resonance imaging (MRI) and evaluate the correlation with sex, age, pubertal development, physical activity and BMI. Methods Wrist, knee and ankle of 958 healthy subjects aged 14.0-21.5 years old were examined using MRI and graded by two radiologists. Correlations of growth plate fusion score with age, pubertal development, physical activity and BMI were assessed. Results Complete growth plate fusion occurred in 75%, 85%, 97%, 98%, 98% and 90%, 97%, 95%, 97%, 98% (radius, femur, proximal- and distal tibia and calcaneus) in 17-year-old females and 19-year-old males, respectively. Complete fusion occurs approximately 2 years earlier in girls than in boys. Pubertal development correlated with growth plate fusion score (rho = 0.514-0.598 for the different growth plate sites) but regular physical activity did not. BMI also correlated with growth plate fusion (rho = 0.186-0.384). Stratified logistic regression showed increased odds ratio (OR F: 2.65-8.71; M: 1.71-4.03) for growth plate fusion of obese or overweight subects versus normal-weight subjects. Inter-observer agreement was high (Kappa = 0.87-0.94). Conclusion Growth plate fusion can be assessed by MRI; occurs in an ascending order, from the foot to the wrist; and is significantly influenced by sex, pubertal development and BMI, but not by physical activity.
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