Search results for "LK"

Calorimetric investigation of water/lecithin/cyclohexane microemulsions

1997

The enthalpies of dilution of water/lecithin/cyclohexane microemulsion-gels at variousR values (R=[water]/[lecithin]) and molar enthalpies of solution of water in lecithin/cyclohexane at a fixed lecithin concentration were determined calorimetrically at 25°C. Through a description of the process of dilution of water/lecithin/cyclohexane microemulsion-gels as one involving mainly the scission of lecithin reversed micelles in to smaller ones, the concentration dependence of the enthalpy was rationalized. Surprisingly, in order to account for the dilution enthalpies, it was not necessary to hypothesize a thermal effect arising from the breakage of the micellar network present in the micremulsi…

Biological clocks and physical functioning in monozygotic female twins

2018

Background Biomarkers of biological aging – DNA methylation age (DNAm age) and leukocyte telomere length (LTL)– correlate strongly with chronological age across the life course. It is, however, unclear how these measures of cellular wear and tear are associated with muscle strength and functional capacity, which are known to decline with older age and are associated with mortality. We investigated if DNAm age and LTL were associated with body composition and physical functioning by examining 48 monozygotic twin sisters. Methods White blood cell DNAm age (predicted years) was calculated from Illumina 450 k BeadChip methylation data using an online calculator. DNAm age acceleration was define…

A twin study on the heritability of walking ability among older women

2006

BACKGROUND This study examined the role of genetic and environmental factors explaining individual differences in women's walking ability in old age. METHODS A maximal walking speed test over 10 meters and a 6-minute walking endurance test were done under standard conditions among 92 monozygotic and 105 dizygotic pairs of twin sisters reared together, aged 63-75 years. RESULTS The mean maximum walking speed was 1.73 +/- 0.32 m/s and the mean distance covered in the 6-minute walking test was 525.6 +/- 77.3 m. Multivariate genetic modeling showed that a minor part of the variances in walking speed (16%, 95% confidence interval [CI]: 0%-54%) and endurance (20%, 95% CI: 0%-56%) were accounted f…

Media portrayals of transitions from work to retirement in two ageing societies : the case of ageing baby boomers in Japan and Finland

2021

This article explores media portrayals of the transition from work to retirement under the circumstances of demographic change through a focus on newspaper discussions about ageing baby boomers in Japan and Finland. Due to their shared characteristics as a distinct population group that advances the rapid ageing of the population, media representations of Japanese and Finnish baby boomers during the transitional period to retirement give insight into the social perceptions of retirement and their implications on later life. Manifest content analysis and subsequent thematic analysis identify that the topic of “work, retirement and pension” dominates media discussions in both countries. Analy…

2020

Abstract Background To examine longitudinal changes in physical performance during the menopausal transition and the role of physical activity (PA) in these changes. Methods Based on follicle-stimulating hormone levels and bleeding diaries, women (47–55 years) were classified as early (n = 89) and late perimenopausal (n = 143) and followed prospectively until postmenopausal status, with mean duration of 17.5 and 13.8 months, respectively. Physical performance was measured by handgrip force, knee extension torque, vertical jumping height, maximal walking speed, and 6-minute walking distance. Physical activity was self-reported and categorized as inactive, low, medium, and high. Longitudinal …

Body Fat and Mobility Are Explained by Common Genetic and Environmental Influences in Older Women

2008

In older adults, mobility limitations often coexist with overweight or obesity, suggesting that similar factors may underlie both traits. This study examined the extent to which genetic and environmental influences explain the association between adiposity and mobility in older women. Body fat percentage (bioimpedance test), walking speed over 10 m, and distance walked in a 6-min test were evaluated in 92 monozygotic (MZ) and 104 dizygotic (DZ) pairs of twin sisters reared together, aged 63-76 years. Genetic and environmental influences on each trait were estimated using age-adjusted multivariate genetic modeling. The analyses showed that the means (and s.d.) for body fat percentage, walkin…

Electrocardiographic and other clinical correlates of walking ability in older women

2009

Abstract The purpose of this study was to examine how resting electrocardiographic (ECG) and other clinical variables, which can be included in a routine clinical examination, predict walking ability in older women. Three hundred and twenty women (63–75 years) without overt cardiac diseases and apparent mobility limitations were studied. Measurements performed were clinical examination (standard 12-lead resting ECG, assessment of physical activity level, presence of chronic diseases, use of beta-blockers, body mass index (BMI), ability to squat, resting blood pressure) and six-minute walking test. Participants walked 533 ± 75 m in the six-minute walking test. The best electrocardiographic p…

Physical Function and All-Cause Mortality in Older Adults Diagnosed With Cancer: A Systematic Review and Meta-Analysis.

2020

Abstract Background Physical function is an independent predictor of numerous chronic diseases, but its association with all-cause mortality in older adults diagnosed with cancer has received little attention. The aim of this study was to conduct a systematic review and meta-analysis on the prospective association between physical function and all-cause mortality in older adults diagnosed with cancer. Methods Two authors systematically searched MEDLINE, EMBASE, and SPORTDiscus databases. Prospective studies reporting associations of baseline physical function with all-cause mortality in patients aged 60 years or older diagnosed with any type of cancer were included. Hazard ratios (HR) with …

Contribution of genetic and environmental factors to individual differences in maximal walking speed with and without second task in older women

2005

Background. Among older people, distraction while walking may increase the risk of falls. Factors underlying individual differences in dual tasking are not fully understood. Our aim was to study the effect of a second task on maximal walking speed and to examine whether individual differences in walking speed measured with and without a second task are accounted for by genetic and environmental influences shared across tasks or specific to each task. Methods. The data were collected from the 101 monozygotic and 116 dizygotic twin pairs aged 63–76 years recruited from the Finnish Twin Cohort. Maximal walking speed (MWS) over 10 m was measured on a laboratory corridor and timed with photocell…

Quantifying Dynamic Balance in Young, Elderly and Parkinson's Individuals: A Systematic Review

2018

Introduction: Falling is one of the primary concerns for people with Parkinson's Disease and occurs predominately during dynamic movements, such as walking. Several methods have been proposed to quantify dynamic balance and to assess fall risk. However, no consensus has been reached concerning which method is most appropriate for examining walking balance during unperturbed and perturbed conditions, particularly in Parkinson's Disease individuals. Therefore, this systematic review aimed to assess the current literature on quantifying dynamic balance in healthy young, elderly and Parkinson's individuals during unperturbed and perturbed walking. Methods: The PubMed database was searched by ti…