Estimation of glottal closure instants in voiced speech using the DYPSA algorithm

Published versio

Towards Working Technicolor: Effective Theories and Dark Matter

A fifth force, of technicolor type, responsible for breaking the electroweak theory is an intriguing extension of the Standard Model. Recently new theories have been shown to feature walking dynamics for a very low number of techniflavors and are not ruled out by electroweak precision measurements. We identify the light degrees of freedom and construct the associated low energy effective theories. These can be used to study signatures and relevant processes in current and future experiments. In our theory the technibaryons are pseudo Goldstone bosons and their masses arise via extended technicolor interactions. There are hypercharge assignments for the techniquarks which renders one of the technibaryons electrically neutral. We investigate the cosmological implications of this scenario and provide a component of dark matter.Comment: RevTeX, 17 pages, 2 figures. V2: more precise explanation of formula (33

A quantitative assessment of group delay methods for identifying glottal closures in voiced speech

Published versio

Long-term interleukin-6 levels and subsequent risk of coronary heart disease: Two new prospective studies and a systematic review

Background The relevance to coronary heart disease (CHD) of cytokines that govern inflammatory cascades, such as interleukin-6 (IL-6), may be underestimated because such mediators are short acting and prone to fluctuations. We evaluated associations of long-term circulating IL-6 levels with CHD risk (defined as nonfatal myocardial infarction [MI] or fatal CHD) in two population-based cohorts, involving serial measurements to enable correction for within-person variability. We updated a systematic review to put the new findings in context. Methods and Findings Measurements were made in samples obtained at baseline from 2,138 patients who had a first-ever nonfatal MI or died of CHD during follow-up, and from 4,267 controls in two cohorts comprising 24,230 participants. Correction for within-person variability was made using data from repeat measurements taken several years apart in several hundred participants. The year-to-year variability of IL-6 values within individuals was relatively high (regression dilution ratios of 0.41, 95% confidence interval [CI] 0.28-0.53, over 4 y, and 0.35, 95% CI 0.23-0.48, over 12 y). Ignoring this variability, we found an odds ratio for CHD, adjusted for several established risk factors, of 1.46 (95% CI 1.29-1.65) per 2 standard deviation (SD) increase of baseline IL-6 values, similar to that for baseline C-reactive protein. After correction for within-person variability, the odds ratio for CHD was 2.14 (95% CI 1.45-3.15) with long-term average ("usual'') IL-6, similar to those for some established risk factors. Increasing IL-6 levels were associated with progressively increasing CHD risk. An updated systematic review of electronic databases and other sources identified 15 relevant previous population-based prospective studies of IL-6 and clinical coronary outcomes (i.e., MI or coronary death). Including the two current studies, the 17 available prospective studies gave a combined odds ratio of 1.61 (95% CI 1.42-1.83) per 2 SD increase in baseline IL-6 (corresponding to an odds ratio of 3.34 [95% CI 2.45-4.56] per 2 SD increase in usual [long-term average] IL-6 levels). Conclusions Long-term IL-6 levels are associated with CHD risk about as strongly as are some major established risk factors, but causality remains uncertain. These findings highlight the potential relevance of IL-6-mediated pathways to CH

Detection of the Low Density Lipoprotein Receptor Gene Pvuii Intron 15 Polymorphism Using the Polymerase Chain Reaction: Association With Plasma Lipid Traits in Healthy Men and Women

We have used anchored PCR to amplify and sequence 1400bp of the 15th intron of the Low Density Lipoprotein (LDL) receptor gene, and have determined oligonucleotides and conditions for the genotyping of the previously reported Pvull polymorphism. The cutting site (CAGCTG) is created by the transition of a CpG to a TpG within the sequence CAGCCG at a position roughly 600bp 5' from the splice acceptor site of exon 16. Genotype was determined in three populationbased samples of healthy individuals. In a group of 318 men and women from Iceland the frequencies of the Intron-15 T (cutting) allele was 0.23 (95% CI, 0.19-0.28) and was similar in men and women. In two groups of men from England (n=385) and Scotland (n=320), the frequency was similar, being 0.23 (0.19-0.27) and 0.25 (0.22-0.28) respectively. Individuals who were homozygous for the T allele had lower levels oftotal-cholesterol triglycerides and apolipoprotein B, than those with other genotypes, and in the combined group of UK men this effect reached statistical significance; compared to the CIC group, the TIT group had 6% lower cholesterol (p=0.02) and 15% lower triglycerides (p=0.03). The lowering effect associated with the TIT genotype was greater in men who were in the lowest terti Ie of body mass index (<25kg/m2) and for the trait of apoB levels, this genotype x obesity interaction was statistically significant (p=0.01). We thus confirm the association between this allele and lower levels of plasma lipid levels previously reported. The availability of a PCR-based method to detect this polymorphism will facilitate further investigation of the impact of LDL-receptor gene variation in determining lipid levels

Body size at birth and age-related macular degeneration in old age

Purpose To study associations between body size at birth and age-related macular degeneration (AMD) in old age. Methods The study sample consists of 1497 community-dwelling individuals (56.1% women) aged 67-89 years with birth data and retinal data collected twice in old age 5 years apart. Birth data (weight, length, birth order) were extracted from original birth records. Digital retinal photographs were graded to determine AMD status. Data on covariates were collected at the baseline physical examination in old age. Multivariable regression analyses were used to study the association between birth data and AMD adjusting for known confounding factors, including birth year cohort effects. Results The prevalence and 5-year incidence of any AMD were 33.1% and 17.0%, respectively. Men and women born in 1930-1936 were significantly leaner and slightly longer at birth compared to those in earlier birth cohorts. There were no consistent associations between weight, length or ponderal index (PI) at birth and AMD in old age even when stratified by birth cohort. Age-related macular degeneration (AMD) prevalence (39.8%) and 5-year incidence (28.6%) were highest in individuals who were in the highest quartile of PI at birth and who were obese in old age. Conclusion Body size at birth was not consistently associated with AMD in old age, suggesting that intrauterine growth might have little direct importance in the development of AMD in old age. It is possible that some yet unknown factors related to larger size at birth and obesity in old age may explain differences in the prevalence and incidence of AMD in the ageing population.Peer reviewe

Assessing cognitive workload using cardiovascular measures and voice

Monitoring cognitive workload has the potential to improve both the performance and fidelity of human decision making. However, previous efforts towards discriminating further than binary levels (e.g., low/high or neutral/high) in cognitive workload classification have not been successful. This lack of sensitivity in cognitive workload measurements might be due to individual differences as well as inadequate methodology used to analyse the measured signal. In this paper, a method that combines the speech signal with cardiovascular measurements for screen and heartbeat classification is introduced. For validation, speech and cardiovascular signals from 97 university participants and 20 airline pilot participants were collected while cognitive stimuli of varying difficulty level were induced with the Stroop colour/word test. For the trinary classification scheme (low, medium, high cognitive workload) the prominent result using classifiers trained on each participant achieved 15.17 ± 0.79% and 17.38 ± 1.85% average misclassification rates indicating good discrimination at three levels of cognitive workload. Combining cardiovascular and speech measures synchronized to each heartbeat and consolidated with short-term dynamic measures might therefore provide enhanced sensitivity in cognitive workload monitoring. The results show that the influence of individual differences is a limiting factor for a generic classification and highlights the need for research to focus on methods that incorporate individual differences to achieve even better results. This method can potentially be used to measure and monitor workload in real time in operational environments

The interaction of adiposity with the CRP gene affects CRP levels: age, gene/environment susceptibilty-Reykjavik study

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldOBJECTIVE: Common diseases often have an inflammatory component reflected by associated markers such as serum C-reactive protein (CRP) levels. Circulating CRP levels have also been associated with adipose tissue as well as with specific CRP genotypes. We examined the interaction between measures of body mass index (BMI), waist circumference and fat percent (total fat measured by bioimpedance) with genotypes of the CRP gene in the determination of CRP levels. METHODS: The first 2296 participants (mean age 76+/-6 years, 42% men) in the Age, Gene/Environment Susceptibility-Reykjavik Study, a multidisciplinary epidemiological study to determine risk factors in aging, were genotyped for 10 single nucleotide polymorphisms (SNPs) in the CRP gene. General linear models with age and terms for interaction of CRP genotypes with BMI, waist circumference and percent fat were used to evaluate the association of genotypes to CRP levels (high-sensitivity method, range 0-10 mg l(-1)) in men and women separately. RESULTS: We focused on the SNP rs1205 that represents the allele that captures the strongest effects of the gene on CRP levels. Carriers of the rs1205 G allele had significantly higher CRP levels than noncarriers in a dose-dependent manner. Compared to the AA genotype, the slope of the increase in CRP with increasing BMI (P=0.045) and waist circumference (P=0.014) was different for the G allele carriers and of similar magnitude in both men and women. The rs1205 interactions were not significant for fat mass percent, suggesting a possible association with fat localization. CONCLUSIONS: This study further illuminates the known association between measures of adiposity and CRP levels and is shown to be dependent on variation in the rs1205 SNP of the CRP gene. The correlated increase in CRP levels with adiposity is accentuated by presence of the G allele

Atrial fibrillation is associated with reduced brain volume and cognitive function independent of cerebral infarcts.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.Atrial fibrillation (AF) has been associated with cognitive decline independent of stroke, suggesting additional effects of AF on the brain. We aimed to assess the association between AF and brain function and structure in a general elderly population.This is a cross-sectional analysis of 4251 nondemented participants (mean age, 76 ± 5 years) in the population-based Age, Gene/Environment Susceptibility-Reykjavik Study. Medical record data were collected for the presence, subtype, and time from first diagnosis of AF; 330 participants had AF. Brain volume measurements, adjusted for intracranial volume, and presence of cerebral infarcts were determined with magnetic resonance imaging. Memory, speed of processing, and executive function composites were calculated from a cognitive test battery. In a multivariable linear regression model, adjustments were made for demographic factors, cardiovascular risk factors, and cerebral infarcts.Participants with AF had lower total brain volume compared with those without AF (P<0.001). The association was stronger with persistent/permanent than paroxysmal AF and with increased time from the first diagnosis of the disease. Of the brain tissue volumes, AF was associated with lower volume of gray and white matter hyperintensities (P<0.001 and P = 0.008, respectively), but not of white matter hyperintensities (P = 0.49). Participants with AF scored lower on tests of memory.AF is associated with smaller brain volume, and the association is stronger with increasing burden of the arrhythmia. These findings suggest that AF has a cumulative negative effect on the brain independent of cerebral infarcts.Landspitali National University Hospital of Iceland Science Fund Helga Jonsdottir and Sigvaldi Kristjansson Memorial Fund National Institutes of Health/N01-AG-1-2100 National Institute on Aging Intramural Research Program Icelandic Heart Association Althingi (the Icelandic Parliament

Similar decline in mortality rate of older persons with and without type 2 diabetes between 1993 and 2004 the Icelandic population-based Reykjavik and AGES-Reykjavik cohort studies.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.A decline in mortality rates due to cardiovascular diseases and all-cause mortality has led to increased life expectancy in the Western world in recent decades. At the same time, the prevalence of type 2 diabetes, a disease associated with a twofold excess risk of cardiovascular disease and mortality, has been increasing. The objective of this study was to estimate the secular trend of cardiovascular and all-cause mortality rates in two population-based cohorts of older persons, with and without type 2 diabetes, examined 11 years apart.1506 participants (42% men) from the population-based Reykjavik Study, examined during 1991-1996 (median 1993), mean age 75.0 years, and 4814 participants (43% men) from the AGES-Reykjavik Study, examined during 2002-2006 (median 2004), mean age 77.2 years, age range in both cohorts 70-87 years. The main outcome measures were age-specific mortality rates due to cardiovascular disease and all causes, over two consecutive 5.7- and 5.3-year follow-up periods.A 32% decline in cardiovascular mortality rate and a 19% decline in all-cause mortality rate were observed between 1993 and 2004. The decline was greater in those with type 2 diabetes, as illustrated by the decline in the adjusted hazard ratio of cardiovascular mortality in individuals with diabetes compared to those without diabetes, from 1.88 (95% CI 1.24-2.85) in 1993 to 1.46 (95% CI 1.11-1.91) in 2004. We also observed a concurrent decrease in major cardiovascular risk factors in both those with and without diabetes. A higher proportion of persons with diabetes received glucose-lowering, hypertensive and lipid-lowering medication in 2004.A decline in cardiovascular and all-cause mortality rates was observed in older persons during the period 1993-2004, in both those with and without type 2 diabetes. This decline may be partly explained by improvements in cardiovascular risk factors and medical treatment over the period studied. However, type 2 diabetes still persists as an independent risk factor for cardiovascular mortality.National Institute of Health/N01-AG-1-2100 NIA Intramural Research Program Icelandic Heart Association (Hjartavernd) Icelandic Parliament (Althingi