234 research outputs found

    An orientation experiment using auditory artificial horizon

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    Presented at the 10th International Conference on Auditory Display (ICAD2004)An orientation experiment was carried out in a spatially immersive virtual environment. The task of subjects was to navigate with 6 degrees of freedom flying method through a predefined route guided by visual cues. Simultaneously they should keep the model oriented in upright position as well as possible. In the experiment we had three different implementations of auditory artificial horizon, and for the reference the subjects accomplish the task also without the auditory support. According to the results the auditory artificial horizon helps subjects to keep the model oriented during the task

    Disease marker combination enhances patient characterization in the Finnish sarcoidosis patients

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    Sarcoidosis is an inflammatory disease of unknown etiology and multiple clinical phenotypes. Clinical manifestations range from asymptomatic disease to severe loss-of-function leading to the hypothesis that sarcoidosis might not be just one disease, but consists of several distinct disease entities each with potentially distinct genetic associations. We have previously demonstrated that in our series HLADRB1* 03:01 and haplotype HLA-DRB1*04:01-DPB1*04:01 are associated with good prognosis sarcoidosis. In our recent work, we found a novel SNP (rs9905945) in the 50upstream region of the ACE gene to be associated with favorable disease prognosis as well. The main objective of this study was to expand the previous results and analyse combined influence of the found ACE SNP rs9905945 with the protective HLA markers HLADRB1*03:01 and HLA-DRB1*04:01-DPB1*04:01 in 188 Finnish sarcoidosis patients (resolved disease, n = 90; persistent disease, n = 98). When combining the frequencies of the rs9905945 and of the HLA markers, the strongest association was found for a combination of either/or both HLA markers and rs9905945 for good disease prognosis (37.1% in resolved vs. 11.3% in persistent, p <0.001, OR = 4.61, (95% CI 2.15-9.86)). In conclusion, we discovered that a combination of the ACE SNP rs9905945 and HLA markers enhance the accuracy for predicting disease course in Finnish sarcoidosis patients further characterizing genetic differences between Finnish sarcoidosis patients with different prognosis. (c) 2017 Elsevier Ltd. All rights reserved.Peer reviewe

    Reducing reversal errors in localizing the source of sound in virtual environment without head tracking

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    International audienceThis paper presents a study about the effect of using additional audio cueing and Head-Related Transfer Function (HRTF) on human performance in sound source localization task without using head movement. The existing techniques of sound spatialization generate reversal errors. We intend to reduce these errors by introducing sensory cues based on sound effects. We conducted and experimental study to evaluate the impact of additional cues in sound source localization task. The results showed the benefit of combining the additional cues and HRTF in terms of the localization accuracy and the reduction of reversal errors. This technique allows significant reduction of reversal errors compared to the use of the HRTF separately. For instance, this technique could be used to improve audio spatial alerting, spatial tracking and target detection in simulation applications when head movement is not included

    Cluster analysis to estimate the risk of preeclampsia in the high-risk Prediction and Prevention of Preeclampsia and Intrauterine Growth Restriction (PREDO) study

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    Objectives Preeclampsia is divided into early-onset (delivery before 34 weeks of gestation) and late-onset (delivery at or after 34 weeks) subtypes, which may rise from different etiopathogenic backgrounds. Early-onset disease is associated with placental dysfunction. Late-onset disease develops predominantly due to metabolic disturbances, obesity, diabetes, lipid dysfunction, and inflammation, which affect endothelial function. Our aim was to use cluster analysis to investigate clinical factors predicting the onset and severity of preeclampsia in a cohort of women with known clinical risk factors. Methods We recruited 903 pregnant women with risk factors for preeclampsia at gestational weeks 12(+0)-13(+6). Each individual outcome diagnosis was independently verified from medical records. We applied a Bayesian clustering algorithm to classify the study participants to clusters based on their particular risk factor combination. For each cluster, we computed the risk ratio of each disease outcome, relative to the risk in the general population. Results The risk of preeclampsia increased exponentially with respect to the number of risk factors. Our analysis revealed 25 number of clusters. Preeclampsia in a previous pregnancy (n = 138) increased the risk of preeclampsia 8.1 fold (95% confidence interval (CI) 5.711.2) compared to a general population of pregnant women. Having a small for gestational age infant (n = 57) in a previous pregnancy increased the risk of early-onset preeclampsia 17.5 fold (95%CI 2.160.5). Cluster of those two risk factors together (n = 21) increased the risk of severe preeclampsia to 23.8-fold (95%CI 5.160.6), intermediate onset (delivery between 34(+0)-36(+6) weeks of gestation) to 25.1-fold (95%CI 3.179.9) and preterm preeclampsia (delivery before 37(+0) weeks of gestation) to 16.4-fold (95%CI 2.052.4). Body mass index over 30 kg/m(2) (n = 228) as a sole risk factor increased the risk of preeclampsia to 2.1-fold (95%CI 1.13.6). Together with preeclampsia in an earlier pregnancy the risk increased to 11.4 (95%CI 4.520.9). Chronic hypertension (n = 60) increased the risk of preeclampsia 5.3-fold (95%CI 2.49.8), of severe preeclampsia 22.2-fold (95%CI 9.941.0), and risk of early-onset preeclampsia 16.7-fold (95%CI 2.057.6). If a woman had chronic hypertension combined with obesity, gestational diabetes and earlier preeclampsia, the risk of term preeclampsia increased 4.8-fold (95%CI 0.121.7). Women with type 1 diabetes mellitus had a high risk of all subgroups of preeclampsia. Conclusion The risk of preeclampsia increases exponentially with respect to the number of risk factors. Early-onset preeclampsia and severe preeclampsia have different risk profile from term preeclampsia.Peer reviewe

    Dysfunction of complement receptors CR3 (CD11b/18) and CR4 (CD11c/18) in pre-eclampsia : a genetic and functional study

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    Objective To study genetic variants and their function within genes coding for complement receptors in pre-eclampsia. Design A case-control study. Setting Pre-eclampsia is a common vascular disease of pregnancy. The clearance of placenta-derived material is one of the functions of the complement system in pregnancy. Population We genotyped 500 women with pre-eclamptic pregnancies and 190 pregnant women without pre-eclampsia, as controls, from the FINNPEC cohort, and 122 women with pre-eclamptic pregnancies and 1905 controls from the national FINRISK cohort. Methods The functional consequences of genotypes discovered by targeted exomic sequencing were explored by analysing the binding of the main ligand iC3b to mutated CR3 or CR4, which were transiently expressed on the surface of COS-1 cells. Main outcome measures Allele frequencies were compared between pre-eclamptic pregnancies and controls in genetic studies. The functional consequences of selected variants were measured by binding assays. Results The most significantly pre-eclampsia-linked CR3 variant M441K (P = 4.27E-4, OR = 1.401, 95% CI = 1.167-1.682) displayed a trend of increased adhesion to iC3b (P = 0.051). The CR4 variant A251T was found to enhance the adhesion of CR4 to iC3b, whereas W48R resulted in a decrease of the binding of CR4 to iC3b. Conclusions Results suggest that changes in complement-facilitated phagocytosis are associated with pre-eclampsia. Further studies are needed to ascertain whether aberrant CR3 and CR4 activity leads to altered pro- and anti-inflammatory cytokine responses in individuals carrying the associated variants, and the role of these receptors in pre-eclampsia pathogenesis. Tweetable abstract Genetic variants of complement receptors CR3 and CR4 have functional consequences that are associated with pre-eclampsia.Peer reviewe

    Analysis of Complement C3 Gene Reveals Susceptibility to Severe Preeclampsia

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    Preeclampsia (PE) is a common vascular disease of pregnancy with genetic predisposition. Dysregulation of the complement system has been implicated, but molecular mechanisms are incompletely understood. In this study, we determined the potential linkage of severe PE to the most central complement gene, C3. Three cohorts of Finnish patients and controls were recruited for a genetic case-control study. Participants were genotyped using Sequenom genotyping and Sanger sequencing. Initially, we studied 259 Finnish patients with severe PE and 426 controls from the Southern Finland PE and the Finnish population-based PE cohorts. We used a custom-made single nucleotide polymorphism (SNP) genotyping assay consisting of 98 SNPs in 18 genes that encode components of the complement system. Following the primary screening, C3 was selected as the candidate gene and consequently Sanger sequenced. Fourteen SNPs from C3 were also genotyped by a Sequenom panel in 960 patients with severe PE and 705 controls, including already sequenced individuals. Three of the 43 SNPs observed within C3 were associated with severe PE: rs2287845 (p = 0.038, OR = 1.158), rs366510 (p = 0.039, OR = 1.158), and rs2287848 (p = 0.041, OR = 1.155). We also discovered 16 SNP haplotypes with extreme linkage disequilibrium in the middle of the gene with a protective (p = 0.044, OR = 0.628) or a predisposing (p = 0.011, OR = 2.110) effect to severe PE depending on the allele combination. Genetic variants associated with PE are located in key domains of C3 and could thereby influence the function of C3. This is, as far as we are aware, the first candidate gene in the complement system with an association to a clinically relevant PE subphenotype, severe PE. The result highlights a potential role for the complement system in the pathogenesis of PE and may help in defining prognostic and therapeutic subgroups of preeclamptic women

    SNP Variants in Major Histocompatibility Complex Are Associate with Sarcoidosis Susceptibility - A Joint Analysis in Four European Populations

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    Sarcoidosis is a multiorgan inflammatory disorder with heritability estimates up to 66%. Previous studies have shown the major histocompatibility complex (MHC) region to be associated with sarcoidosis, suggesting a functional role for antigen-presenting molecules and immune mediators in the disease pathogenesis. To detect variants predisposing to sarcoidosis and to identify genetic differences between patient subgroups, we studied four genes in the MHC Class III region (LTA, TNF, AGER, BTNL2) and HLA-DRA with tag-SNPs and their relation to HLA-DRB1 alleles. We present results from a joint analysis of four study populations (Finnish, Swedish, Dutch, and Czech). Patients with sarcoidosis (n = 805) were further subdivided based on the disease activity and the presence of Lofgren's syndrome. In a joint analysis, seven SNPs were associated with non-Lofgren sarcoidosis (NL; the strongest association with rs3177928, P = 1.79E-07, OR = 1.9) and eight with Lofgren's syndrome [ Lofgren syndrome (LS); the strongest association with rs3129843, P = 3.44E-12, OR = 3.4] when compared with healthy controls (n = 870). Five SNPs were associated with sarcoidosis disease course (the strongest association with rs3177928, P = 0.003, OR = 1.9). The high linkage disequilibrium (LD) between SNPs and an HLA-DRB1 challenged the result interpretation. When the SNPs and HLA-DRB1 alleles were analyzed together, independent association was observed for four SNPs in the HLA-DRA/BTNL2 region: rs3135365 (NL; P = 0.015), rs3177928 (NL; P <0.001), rs6937545 (LS; P = 0.012), and rs5007259 (disease activity; P = 0.002). These SNPs act as expression quantitative trait loci (eQTL) for HLA-DRB1 and/or HLA-DRB5. In conclusion, we found novel SNPs in BTNL2 and HLA-DRA regions associating with sarcoidosis. Our finding further establishes that polymorphisms in the HLA-DRA and BTNL2 have a role in sarcoidosis susceptibility. This multi-population study demonstrates that at least a part of these associations are HLA-DRB1 independent (e.g., not due to LD) and shared across ancestral origins. The variants that were independent of HLA-DRB1 associations acted as eQTL for HLA-DRB1 and/or -DRB5, suggesting a role in regulating gene expression.Peer reviewe

    A comprehensive 1000 Genomes-based genome-wide association meta-analysis of coronary artery disease

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    Existing knowledge of genetic variants affecting risk of coronary artery disease (CAD) is largely based on genome-wide association studies (GWAS) analysis of common SNPs. Leveraging phased haplotypes from the 1000 Genomes Project, we report a GWAS meta-analysis of 185 thousand CAD cases and controls, interrogating 6.7 million common (MAF>0.05) as well as 2.7 million low frequency (0.005<MAF<0.05) variants. In addition to confirmation of most known CAD loci, we identified 10 novel loci, eight additive and two recessive, that contain candidate genes that newly implicate biological processes in vessel walls. We observed intra-locus allelic heterogeneity but little evidence of low frequency variants with larger effects and no evidence of synthetic association. Our analysis provides a comprehensive survey of the fine genetic architecture of CAD showing that genetic susceptibility to this common disease is largely determined by common SNPs of small effect siz
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