912 research outputs found
Leisure activity associated with cognitive ability level, but not cognitive change
Although activity participation is promoted as cognitively-protective, critical questions of causality remain. In a cohort followed every five years from age 75 to 85 years, potential reciprocal associations between level and change in leisure activity participation and level and change in cognitive abilities were examined. Participants in the Glostrup 1914 Cohort, a longitudinal study of ageing, completed standardised cognitive ability tests and reported their leisure activity participation (11 activities defined a leisure activity score) at ages 75, 80 and 85. Higher leisure activity was associated with higher cognitive ability (significant correlations ranged from .15 to .31, p < .05). Between ages 75 and 85, participation in leisure activities and cognitive ability declined significantly. Growth curve models, which provided latent variables for level of and 10-year change in both leisure activity and cognitive ability, confirmed the positive association between levels of leisure activity and cognitive ability (path coefficient = .36, p < .001); however, leisure activity level or change was not associated with cognitive change. Although a positive association between leisure activity and cognitive ability was reportedâthe likely precedents of this are discussedâthere was no evidence that a higher level or maintenance of leisure activity was protective against cognitive decline across a 10-year follow-up
Older people and preventive home visits
In 1996, national preventive efforts for the elderly were introduced in Denmark with a general offer of home visits by preventive staff.The focal point of the preventive home visits has been the functional decline and the corresponding early and coordinated follow-up activities. This has proved an extremely suitable instrument in activities aimed at maintaining elderly people's autonomy, independence, and functional ability, in allowing them to continue taking care of themselves
Observation of Periodic Orbits on Curved Two - dimensional Geometries
We measure elastomechanical spectra for a family of thin shells. We show that
these spectra can be described by a "semiclassical" trace formula comprising
periodic orbits on geodesics, with the periods of these orbits consistent with
those extracted from experiment. The influence of periodic orbits on spectra in
the case of two-dimensional curved geometries is thereby demonstrated, where
the parameter corresponding to Planck's constant in quantum systems involves
the wave number and the curvature radius. We use these findings to explain the
marked clustering of levels when the shell is hemispherical
Intake of Dairy Products in Relation to Periodontitis in Older Danish Adults
This cross-sectional study investigates whether calcium intakes from dairy and non-dairy sources, and absolute intakes of various dairy products, are associated with periodontitis. The calcium intake (mg/day) of 135 older Danish adults was estimated by a diet history interview and divided into dairy and non-dairy calcium. Dairy food intake (g/day) was classified into four groups: milk, cheese, fermented foods and other foods. Periodontitis was defined as the number of teeth with attachment loss âĽ3 mm. Intakes of total dairy calcium (Incidence-rate ratio (IRR) = 0.97; <em>p</em> = 0.021), calcium from milk (IRR = 0.97; <em>p</em> = 0.025) and fermented foods (IRR = 0.96; <em>p </em>= 0.03) were inversely and significantly associated with periodontitis after adjustment for age, gender, education, sucrose intake, alcohol consumption, smoking, physical activity, vitamin D intake, heart disease, visits to the dentist, use of dental floss and bleeding on probing, but non-dairy calcium, calcium from cheese and other types of dairy food intakes were not. Total dairy foods (IRR = 0.96; <em>p</em> = 0.003), milk (IRR = 0.96; <em>p</em> = 0.028) and fermented foods intakes (IRR = 0.97; <em>p</em> = 0.029) were associated with reduced risk of periodontitis, but cheese and other dairy foods intakes were not. These results suggest that dairy calcium, particularly from milk and fermented products, may protect against periodontitis. Prospective studies are required to confirm these findings
Minimal gene regulatory circuits for a lysis-lysogeny choice in the presence of noise
Gene regulatory networks (GRNs) that make reliable decisions should have design features to cope with random fluctuations in the levels or activities of biological molecules. The phage GRN makes a lysis-lysogeny decision informed by the number of phages infecting the cell. To analyse the design of decision making GRNs, we generated random in silico GRNs comprised of two or three transcriptional regulators and selected those able to perform a -like decision in the presence of noise. Various two-protein networks analogous to the CI-Cro GRN worked in noise-less conditions but failed when noise was introduced. Adding a CII-like protein significantly improved robustness to noise. CII relieves the CI-like protein of its âdeciderâ function, allowing CI to be optimized as a decision âmaintainerâ. CII's lysogenic decider function was improved by its instability and rapid removal once the decision was taken, preventing its interference with maintenance. A more reliable decision also resulted from simulated co-transcription of the genes for CII and the Cro-like protein, which correlates fluctuations in these opposing decider functions and makes their ratio less noisy. Thus, the decision network contains design features for reducing and resisting noise.Mikkel Avlund, Sandeep Krishna, Szabolcs Semsey, Ian B. Dodd and Kim Sneppe
Anomalous Transport in Conical Granular Piles
Experiments on 2+1-dimensional piles of elongated particles are performed.
Comparison with previous experiments in 1+1 dimensions shows that the addition
of one extra dimension to the dynamics changes completely the avalanche
properties, appearing a characteristic avalanche size. Nevertheless, the time
single grains need to cross the whole pile varies smoothly between several
orders of magnitude, from a few seconds to more than 100 hours. This behavior
is described by a power-law distribution, signaling the existence of scale
invariance in the transport process.Comment: Accepted in PR
- âŚ