| 1. |
- Andersson, Niklas, 1970, et al.
(författare)
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Variants of the interleukin-1 receptor antagonist gene are associated with fat mass in men
- 2009
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 33:5, s. 525-533
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Tidskriftsartikel (refereegranskat)abstract
- Context: Immune functions seem to have connections to variations in body fat mass. Studies of knockout mice indicate that endogenous interleukin (IL)-1 can suppress mature-onset obesity. Objective: To systematically investigate our hypotheses that single- nucleotide polymorphisms (SNPs) and/or haplotypes variants in the IL-1 gene system are associated with fat mass. Subjects: The Gothenburg osteoporosis and obesity determinants (GOOD) study is a population-based cross-sectional study of 18-20 year-old men (n = 1068), from Gothenburg, Sweden. Major findings were confirmed in elderly men (n = 3014) from the Swedish part of the osteoporotic fractures in men (MrOS) multicenter population-based study. Main Outcome Measure: The genotype distributions and their association with body fat mass in different compartments, measured with dual-energy X-ray absorptiometry (DXA). Results: Out of 15 investigated SNPs in the IL-1 receptor antagonist (IL1RN) gene, a recently identified 30 untranslated region C4T (rs4252041, minor allele frequency 4%) SNP was associated with the primary outcome total fat mass (P = 0.003) and regional fat masses, but not with lean body mass or serum IL-1 receptor 1 (IL1RN) levels. This SNP was also associated with body fat when correcting the earlier reported IL1RN_2018 T4C (rs419598) SNP (in linkage disequilibrium with a well-studied variable number tandem repeat of 86 bp). The association between rs4252041 SNP and body fat was confirmed in the older MrOS population (P = 0.03). The rs4252041 SNP was part of three haplotypes consisting of five adjacent SNPs that were identified by a sliding window approach. These haplotypes had a highly significant global association with total body fat (P < 0.001). None of the other investigated members of the IL-1 gene family displayed any SNPs that have not been described previously to be significantly associated with body fat. Conclusions: The IL1RN gene, shown to enhance obesity by suppressing IL-1 effects in experimental animals, have no previously described gene polymorphisms and haplotypes that are associated with fat, but not lean mass in two populations of men. International Journal of Obesity (2009) 33, 525-533; doi: 10.1038/ijo.2009.47; published online 17 March 2009
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| 2. |
- Grundberg, Elin, et al.
(författare)
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Population genomics in a disease targeted primary cell model
- 2009
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051 .- 1549-5469. ; 19:11, s. 1942-1952
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Tidskriftsartikel (refereegranskat)abstract
- The common genetic variants associated with complex traits typically lie in noncoding DNA and may alter gene regulation in a cell type-specific manner. Consequently, the choice of tissue or cell model in the dissection of disease associations is important. We carried out an expression quantitative trait loci (eQTL) study of primary human osteoblasts (HOb) derived from 95 unrelated donors of Swedish origin, each represented by two independently derived primary lines to provide biological replication. We combined our data with publicly available information from a genome-wide association study (GWAS) of bone mineral density (BMD). The top 2000 BMD-associated SNPs (P < approximately 10(-3)) were tested for cis-association of gene expression in HObs and in lymphoblastoid cell lines (LCLs) using publicly available data and showed that HObs have a significantly greater enrichment (threefold) of converging cis-eQTLs as compared to LCLs. The top 10 BMD loci with SNPs showing strong cis-effects on gene expression in HObs (P = 6 x 10(-10) - 7 x 10(-16)) were selected for further validation using a staged design in two cohorts of Caucasian male subjects. All 10 variants were tested in the Swedish MrOS Cohort (n = 3014), providing evidence for two novel BMD loci (SRR and MSH3). These variants were then tested in the Rotterdam Study (n = 2090), yielding converging evidence for BMD association at the 17p13.3 SRR locus (P(combined) = 5.6 x 10(-5)). The cis-regulatory effect was further fine-mapped to the proximal promoter of the SRR gene (rs3744270, r(2) = 0.5, P = 2.6 x 10(-15)). Our results suggest that primary cells relevant to disease phenotypes complement traditional approaches for prioritization and validation of GWAS hits for follow-up studies.
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| 3. |
- Atroshi, Isam, et al.
(författare)
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Low calcaneal bone mineral density and the risk of distal forearm fracture in women and men: a population-based case-control study.
- 2009
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Ingår i: Bone. - : Elsevier BV. - 1873-2763 .- 8756-3282. ; 45:4, s. 789-93
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: We used dual X-ray absorptiometry (DXA) to measure calcaneal bone mineral density (BMD) and estimate the prevalence of osteoporosis in a population with distal forearm fracture and a normative cohort. METHODS: Patients 20 to 80 years of age with distal forearm fracture treated at one emergency hospital during two consecutive years were invited to calcaneal BMD measurement; 270 women (81%) and 64 men (73%) participated. A DXA heel scanner estimated BMD (g/cm(2)) and T-scores. Osteoporosis was defined as T-score< or =-2.5 SD. Of the fracture cohort, 254 women aged 40-80 years and 27 men aged 60-80 years were compared with population-based control cohorts comprising 171 women in the age groups 50, 60, 70 and 80 years and 75 men in the age groups 60, 70, and 80 years. RESULTS: In the fracture population no woman below 40 years or man below 60 years of age had osteoporosis. In women aged 40-80 years the prevalence of osteoporosis in the distal forearm fracture cohort was 34% and in the population-based controls was 25%; the age-adjusted prevalence ratio (PR) was 1.32 (95% CI 1.00-1.76). In the subgroup of women aged 60-80 years the age-adjusted prevalence ratio of osteoporosis was 1.28 (95% CI 0.95-1.71). In men aged 60-80 years the prevalence of osteoporosis in the fracture cohort was 44% and in the population-based controls was 8% (PR 6.31, 95% CI 2.78-14.4). The age-adjusted odds ratio for fracture associated with a 1-SD reduction in calcaneal BMD was in women aged 40-80 years 1.4 (95% CI 1.1-1.8), in the subgroup of women aged 60-80 years 1.2 (95% CI 0.95-1.6), and in men aged 60-80 years 2.6 (95% CI 1.7-4.1). Among those aged 60-80 years the area under the ROC curve was in women 0.56 (95% CI 0.49-0.63) and in men 0.80 (95% CI 0.70-0.80). CONCLUSIONS: The age-adjusted prevalence of osteoporosis based on calcaneal BMD is higher in individuals with distal forearm fracture than in population-based controls. BMD impairment is associated with increased odds ratio for forearm fracture in both women and men but the differences between cases and controls are more pronounced in men than in women, which may have implications in fracture prevention.
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| 4. |
- Bergh, Tomas, et al.
(författare)
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Modeling and presentation of the series magnetized synchronous machine
- 2006
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Ingår i: International Symposium on Power Electronics, Electrical Drives, Automation and Motion, 2006. SPEEDAM 2006. ; 2006, s. 463-468
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Konferensbidrag (refereegranskat)abstract
- In this paper mathematical modeling and a dedicated control algorithm of the patented Series Magnetized Synchronous Machine (SMSM) are presented. The SMSM is an electrically magnetized synchronous machine, where the field current is supplied via the stator windings and a diode bridge rectifier. For the SMSM there is no need for additional field voltage supply and the SMSM exhibits significantly faster field current dynamics than the Electrically magnetized synchronous machine (EMSM). Other additional benefits that follow are the possibility to utilize passive field weakening and simple sensor-less operation. The SMSM is in this case considered for an automotive application and therefore relates to the operating region of high rotational speed, low voltage and high current. This region of operation is considered to be the most challenging for this type of machine.
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| 5. |
- Bergman, Eva, et al.
(författare)
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Longitudinal study of patients after myocardial infarction : Sense of coherence, quality of life, and symptoms
- 2009
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Ingår i: Heart & Lung. - : Elsevier BV. - 0147-9563 .- 1527-3288. ; 38:2, s. 129-140
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Myocardial infarction has pronounced effects on an individual that demand changes in lifestyle. Health is influenced by whether the individual experiences the world as comprehensible, meaningful, and manageable, that is, has a sense of coherence (SOC). High SOC scores indicate that the individual probably manages the situation by understanding the context and connections: action and effect. OBJECTIVE: The study objective was to identify the SOC, assess the quality of life (Short Form-12 Health Survey Questionnaire), assess the symptoms using the Seattle Angina Questionnaire, and create health curves from a baseline for patients with a first myocardial infarction. METHODS: A longitudinal and predictive Study of 100 participants in the heart care unit of a county hospital in southern Sweden was performed. RESULTS: Women score lower on SOC than men. Persons with high SOC scores have fewer angina attacks, are more physically active, drink more alcohol, are more satisfied with their treatments, and have better disease perception. CONCLUSION: By following SOC scores, a trend emerges that Suggests it may be a useful tool for identifying those who will need extra support.
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| 6. |
- Carneiro, Ana, et al.
(författare)
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Prognostic impact of array-based genomic profiles in esophageal squamous cell cancer
- 2008
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 8:98
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Tidskriftsartikel (refereegranskat)abstract
- Background: Esophageal squamous cell carcinoma (ESCC) is a genetically complex tumor type and a major cause of cancer related mortality. Although distinct genetic alterations have been linked to ESCC development and prognosis, the genetic alterations have not gained clinical applicability. We applied array-based comparative genomic hybridization (aCGH) to obtain a whole genome copy number profile relevant for identifying deranged pathways and clinically applicable markers. Methods: A 32 k aCGH platform was used for high resolution mapping of copy number changes in 30 stage I-IV ESCC. Potential interdependent alterations and deranged pathways were identified and copy number changes were correlated to stage, differentiation and survival. Results: Copy number alterations affected median 19% of the genome and included recurrent gains of chromosome regions 5p, 7p, 7q, 8q, 10q, 11q, 12p, 14q, 16p, 17p, 19p, 19q, and 20q and losses of 3p, 5q, 8p, 9p and 11q. High-level amplifications were observed in 30 regions and recurrently involved 7p11 (EGFR), 11q13 (MYEOV, CCND1, FGF4, FGF3, PPFIA, FAD, TMEM16A, CTTS and SHANK2) and 11q22 (PDFG). Gain of 7p22.3 predicted nodal metastases and gains of 1p36.32 and 19p13.3 independently predicted poor survival in multivariate analysis. Conclusion: aCGH profiling verified genetic complexity in ESCC and herein identified imbalances of multiple central tumorigenic pathways. Distinct gains correlate with clinicopathological variables and independently predict survival, suggesting clinical applicability of genomic profiling in ESCC.
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| 7. |
- Dán, György, et al.
(författare)
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A rate-distortion based comparison of media-dependent FEC and MDC for real-time audio
- 2006
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Ingår i: 2006 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS, VOLS 1-12. - 9781424403547 ; , s. 1002-1007
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Konferensbidrag (refereegranskat)abstract
- Applications that require low loss probabilities in today's Internet have to employ some end-to-end error-recovery mechanism. For interactive applications with strict delay constraints, the delay introduced by the applied schemes has to be low as well. In this paper we compare two schemes proposed for error recovery for real-time audio applications: media-dependent forward error correction (MD-FEC) and multiple description coding (MDC). We conclude that MDC always performs better than MD-FEC, and that the stationary loss probability plays a key role in the choice of the optimal parameters for these schemes. Combining the analytical results with the loss characteristics of measured traces of VoIP calls we conclude that in the current Internet these schemes give considerable gains for streams with a high code rate only, and for these streams MDC can decrease the average distortion significantly better than MD-FEC.
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| 8. |
- Dán, György, et al.
(författare)
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Are multiple descriptions better than one?
- 2005
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Ingår i: NETWORKING 2005: NETWORKING TECHNOLOGIES, SERVICES, AND PROTOCOLS; PERFORMANCE OF COMPUTER AND COMMUNICATION NETWORKS; MOBILE AND WIRELESS COMMUNICATIONS SYSTEMS. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 3540258094 ; , s. 684-696
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Konferensbidrag (refereegranskat)abstract
- In this paper we compare three schemes proposed for error recovery for real-time multimedia applications: media-dependent forward error correction (MD-FEC) proposed for real-time audio, media-independent forward error correction (MI-FEC) proposed for real-time video and the recently re-discovered multiple description coding (MDC). We provide a detailed queueing analysis for these schemes considering bursty traffic sources, and combine results from information theory and queueing theory to analyze their performance bounds. We conclude that MDC always performs better than MD-FEC, and that the average loss probability plays a key role in the choice of the optimal parameters. We also show that MDC outperforms MI-FEC if packet losses are highly correlated, like in the current Internet and the available delay for error control is low.
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| 9. |
- Dan, György
(författare)
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Internet Video Transmission
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The Internet has rapidly evolved from being a scientific experiment to a commercial network connecting millions of hosts that carries traffic generated by a large amount of applications with diverse requirements. Its architecture was however designed to enable efficient point-to-point delivery of bulk data, and can not provide statistical guarantees on the timely delivery of delay sensitive data such as streaming and real-time multimedia. Thus, applications that require low loss probabilities in today's Internet have to use some end-to-end error recovery mechanism. For delay sensitive applications the introduced latency by the applied schemes has to be low as well. Traffic control functions such as delay limited shaping and forward error correction (FEC), and multiple description coding (MDC) have been proposed for variable bitrate video. Their major drawback is, however, that it is difficult to predict their efficiency, as it depends on many factors like the characteristics of the stream itself, the characteristics of the traffic in the network and the network parameters. Consequently, it is difficult to decide which control mechanisms to employ, how to combine them and to choose the right parameters (e.g. block length, code rate) for optimal performance. In this thesis we present results on the efficiency of traffic control functions and MDC for video transmission based on mathematical models and simulations. We investigate the efficiency of delay limited traffic shaping and the trade-offs in the joint use of traffic shaping and forward error correction. We identify the packet size distribution of the traffic in the network as an additional factor that may influence the efficiency of FEC, and present a thorough analysis of its possible effects. We present an analytical comparison of MDC versus media-dependent FEC and media-independent FEC, and based on the results we conclude that MDC is a promising error control solution for multimedia communications with very strict delay bounds in an environment with bursty losses. We combine the analytical results with traces from measurements performed on the Internet to evaluate how efficient these error control schemes are under real loss patterns. We compare the efficiency of MDC and media-dependent FEC in the presence of channel estimation errors; we propose a new rate allocation method, which is robust to mis-estimations of the channel state and which improves error resilience on non-stationary channels. Finally we present an analytical model of the performance of an end-point-based multimedia streaming architecture based on multiple distribution trees and forward error correction, and analyze the behavior of the architecture for a large number of nodes.
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| 10. |
- Dán, György, et al.
(författare)
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On the asymptotic behavior of end-point-based multicast streaming
- 2006
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Ingår i: 2006 International Zurich Seminar on Communications. - NEW YORK : IEEE. - 1424400910 ; , s. 66-69
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Konferensbidrag (refereegranskat)abstract
- In this paper we propose an analytical model of a resilient, tree-based end-node multicast streaming architecture that employs path diversity and forward error correction for improved resilience to node churns and packet losses. We show that this architecture can distribute data to nodes arbitrarily far away from the root of the trees as long as the loss probability is lower than a certain threshold, but the probability of packet reception suddenly drops to zero once this threshold is exceeded. The value of the threshold depends on the ratio of redundancy and on the number of the distribution trees.
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