2,741 research outputs found
Associations between health-related quality of life, physical function and fear of falling in older fallers receiving home care
Falls and injuries in older adults have significant consequences and costs, both personal and to society. Although having a high incidence of falls, high prevalence of fear of falling and a lower quality of life, older adults receiving home care are underrepresented in research on older fallers. The objective of this study is to determine the associations between health-related quality of life (HRQOL), fear of falling and physical function in older fallers receiving home care
A new method to quantify and compare the multiple components of fitness-A study case with kelp niche partition by divergent microstage adaptations to Temperature
Point 1 Management of crops, commercialized or protected species, plagues or life-cycle evolution are subjects requiring comparisons among different demographic strategies. The simpler methods fail in relating changes in vital rates with changes in population viability whereas more complex methods lack accuracy by neglecting interactions among vital rates. Point 2 The difference between the fitness (evaluated by the population growth rate.) of two alternative demographies is decomposed into the contributions of the differences between the pair-wised vital rates and their interactions. This is achieved through a full Taylor expansion (i.e. remainder = 0) of the demographic model. The significance of each term is determined by permutation tests under the null hypothesis that all demographies come from the same pool. Point 3 An example is given with periodic demographic matrices of the microscopic haploid phase of two kelp cryptic species observed to partition their niche occupation along the Chilean coast. The method provided clear and synthetic results showing conditional differentiation of reproduction is an important driver for their differences in fitness along the latitudinal temperature gradient. But it also demonstrated that interactions among vital rates cannot be neglected as they compose a significant part of the differences between demographies. Point 4 This method allows researchers to access the effects of multiple effective changes in a life-cycle from only two experiments. Evolutionists can determine with confidence the effective causes for changes in fitness whereas population managers can determine best strategies from simpler experimental designs.CONICYT-FRENCH EMBASSADY Ph.D. gran
Long-range Kondo signature of a single magnetic impurity
The Kondo effect, one of the oldest correlation phenomena known in condensed
matter physics, has regained attention due to scanning tunneling spectroscopy
(STS) experiments performed on single magnetic impurities. Despite the
sub-nanometer resolution capability of local probe techniques one of the
fundamental aspects of Kondo physics, its spatial extension, is still subject
to discussion. Up to now all STS studies on single adsorbed atoms have shown
that observable Kondo features rapidly vanish with increasing distance from the
impurity. Here we report on a hitherto unobserved long range Kondo signature
for single magnetic atoms of Fe and Co buried under a Cu(100) surface. We
present a theoretical interpretation of the measured signatures using a
combined approach of band structure and many-body numerical renormalization
group (NRG) calculations. These are in excellent agreement with the rich
spatially and spectroscopically resolved experimental data.Comment: 7 pages, 3 figures + 8 pages supplementary material; Nature Physics
  (Jan 2011 - advanced online publication
A falls prevention programme to improve quality of life, physical function and falls efficacy in older people receiving home help services: study protocol for a randomised controlled trial
BACKGROUND:
Falls and fall-related injuries in older adults are associated with great burdens, both for the individuals, the health care system and the society. Previous research has shown evidence for the efficiency of exercise as falls prevention. An understudied group are older adults receiving home help services, and the effect of a falls prevention programme on health-related quality of life is unclear. The primary aim of this randomised controlled trial is to examine the effect of a falls prevention programme on quality of life, physical function and falls efficacy in older adults receiving home help services. A secondary aim is to explore the mediating factors between falls prevention and health-related quality of life.
METHODS:
The study is a single-blinded randomised controlled trial. Participants are older adults, aged 67 or older, receiving home help services, who are able to walk with or without walking aids, who have experienced at least one fall during the last 12 months and who have a Mini Mental State Examination of 23 or above. The intervention group receives a programme, based on the Otago Exercise Programme, lasting 12 weeks including home visits and motivational telephone calls. The control group receives usual care. The primary outcome is health-related quality of life (SF-36). Secondary outcomes are leg strength, balance, walking speed, walking habits, activities of daily living, nutritional status and falls efficacy. All measurements are performed at baseline, following intervention at 3 months and at 6 months' follow-up. Sample size, based on the primary outcome, is set to 150 participants randomised into the two arms, including an estimated 15-20% drop out. Participants are recruited from six municipalities in Norway.
DISCUSSION:
This trial will generate new knowledge on the effects of an exercise falls prevention programme among older fallers receiving home help services. This knowledge will be useful for clinicians, for health managers in the primary health care service and for policy makers
Light smoking at base-line predicts a higher mortality risk to women than to men; evidence from a cohort with long follow-up
BACKGROUND: There is conflicting evidence as to whether smoking is more harmful to women than to men. The UK Cotton Workers’ Cohort was recruited in the 1960s and contained a high proportion of men and women smokers who were well matched in terms of age, job and length of time in job. The cohort has been followed up for 42 years. METHODS: Mortality in the cohort was analysed using an individual relative survival method and Cox regression. Whether smoking, ascertained at baseline in the 1960s, was more hazardous to women than to men was examined by estimating the relative risk ratio women to men, smokers to never smoked, for light (1–14), medium (15–24), heavy (25+ cigarettes per day) and former smoking. RESULTS: For all-cause mortality relative risk ratios were 1.35 for light smoking at baseline (95% CI 1.07-1.70), 1.15 for medium smoking (95% CI 0.89-1.49) and 1.00 for heavy smoking (95% CI 0.63-1.61). Relative risk ratios for light smoking at baseline for circulatory system disease was 1.42 (95% CI 1.01 to 1.98) and for respiratory disease was 1.89 (95% CI 0.99 to 3.63). Heights of participants provided no explanation for the gender difference. CONCLUSIONS: Light smoking at baseline was shown to be significantly more hazardous to women than to men but the effect decreased as consumption increased indicating a dose response relationship. Heavy smoking was equally hazardous to both genders. This result may help explain the conflicting evidence seen elsewhere. However gender differences in smoking cessation may provide an alternative explanation
How the other half lives: CRISPR-Cas's influence on bacteriophages
CRISPR-Cas is a genetic adaptive immune system unique to prokaryotic cells
used to combat phage and plasmid threats. The host cell adapts by incorporating
DNA sequences from invading phages or plasmids into its CRISPR locus as
spacers. These spacers are expressed as mobile surveillance RNAs that direct
CRISPR-associated (Cas) proteins to protect against subsequent attack by the
same phages or plasmids. The threat from mobile genetic elements inevitably
shapes the CRISPR loci of archaea and bacteria, and simultaneously the
CRISPR-Cas immune system drives evolution of these invaders. Here we highlight
our recent work, as well as that of others, that seeks to understand phage
mechanisms of CRISPR-Cas evasion and conditions for population coexistence of
phages with CRISPR-protected prokaryotes.Comment: 24 pages, 8 figure
Prime movers : mechanochemistry of mitotic kinesins
Mitotic spindles are self-organizing protein machines that harness teams of multiple force generators to drive chromosome segregation. Kinesins are key members of these force-generating teams. Different kinesins walk directionally along dynamic microtubules, anchor, crosslink, align and sort microtubules into polarized bundles, and influence microtubule dynamics by interacting with microtubule tips. The mechanochemical mechanisms of these kinesins are specialized to enable each type to make a specific contribution to spindle self-organization and chromosome segregation
Association studies of up to 1.2 million individuals yield new insights into the genetic etiology of tobacco and alcohol use.
Tobacco and alcohol use are leading causes of mortality that influence risk for many complex diseases and disorders1. They are heritable2,3 and etiologically related4,5 behaviors that have been resistant to gene discovery efforts6-11. In sample sizes up to 1.2 million individuals, we discovered 566 genetic variants in 406 loci associated with multiple stages of tobacco use (initiation, cessation, and heaviness) as well as alcohol use, with 150 loci evidencing pleiotropic association. Smoking phenotypes were positively genetically correlated with many health conditions, whereas alcohol use was negatively correlated with these conditions, such that increased genetic risk for alcohol use is associated with lower disease risk. We report evidence for the involvement of many systems in tobacco and alcohol use, including genes involved in nicotinic, dopaminergic, and glutamatergic neurotransmission. The results provide a solid starting point to evaluate the effects of these loci in model organisms and more precise substance use measures
A comprehensive 1000 Genomes-based genome-wide association meta-analysis of coronary artery disease
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
A meta-analytic review of stand-alone interventions to improve body image
Objective
Numerous stand-alone interventions to improve body image have been developed. The
present review used meta-analysis to estimate the effectiveness of such interventions, and
to identify the specific change techniques that lead to improvement in body image.
Methods
The inclusion criteria were that (a) the intervention was stand-alone (i.e., solely focused on
improving body image), (b) a control group was used, (c) participants were randomly
assigned to conditions, and (d) at least one pretest and one posttest measure of body
image was taken. Effect sizes were meta-analysed and moderator analyses were conducted.
A taxonomy of 48 change techniques used in interventions targeted at body image
was developed; all interventions were coded using this taxonomy.
Results
The literature search identified 62 tests of interventions (N = 3,846). Interventions produced
a small-to-medium improvement in body image (d+ = 0.38), a small-to-medium reduction in
beauty ideal internalisation (d+ = -0.37), and a large reduction in social comparison tendencies
(d+ = -0.72). However, the effect size for body image was inflated by bias both within
and across studies, and was reliable but of small magnitude once corrections for bias were
applied. Effect sizes for the other outcomes were no longer reliable once corrections for
bias were applied. Several features of the sample, intervention, and methodology moderated
intervention effects. Twelve change techniques were associated with improvements in
body image, and three techniques were contra-indicated.
Conclusions
The findings show that interventions engender only small improvements in body image, and
underline the need for large-scale, high-quality trials in this area. The review identifies effective
techniques that could be deployed in future interventions
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