4,967 research outputs found
Age, Retirement and Expenditure Patterns: An Econometric Study of Older Canadian Households
The paper explores the allocation of consumption expenditure by the older population among different categories of goods and services, and how expenditure patterns change with age within that population. Of particular interest is whether observed differences between pre-retirement and post-retirement patterns are a consequence of changes in "tastes" or reductions in income. An adapted form of the Deaton and Muellbauer Almost Ideal Demand System is estimated with data from six Family Expenditure Surveys and used to investigate that question. The findings suggest that observed changes in budget allocations are most closely related to reductions in income.consumption expenditure; retirement; income
Invariant tensors and Casimir operators for simple compact Lie groups
The Casimir operators of a Lie algebra are in one-to-one correspondence with
the symmetric invariant tensors of the algebra. There is an infinite family of
Casimir operators whose members are expressible in terms of a number of
primitive Casimirs equal to the rank of the underlying group. A systematic
derivation is presented of a complete set of identities expressing
non-primitive symmetric tensors in terms of primitive tensors. Several examples
are given including an application to an exceptional Lie algebra.Comment: 11 pages, LaTeX, minor changes, version in J. Math. Phy
Enhanced star formation: The importance of bars in spiral galaxies
It was found that among an IR luminous subset of nearby spiral galaxies, nearly all of the systems with IRAS colors and luminosities indicative of enhanced star formation are barred. Radio continuum and IR spectroscopic results support the hypothesis that this emission originates within the central 2 kpc; possibly in a circumnuclear ring. It was also found that outer rings are over represented among these barred systems and suggest possible reasons for this phenomena
Updating predictive accident models of modern rural single carriageway A-roads
Reliable predictive accident models (PAMs) are essential to design and maintain safe road networks and yet the models most commonly used in the UK were derived using data collected 20 to 30 years ago. Given that the national personal injury accident total fell by some 30% in the last 25 years, while road traffic increased by over 60%, significant errors in scheme appraisal and evaluation based on the models currently in use seem inevitable. In this paper the temporal transferability of PAMs for modern rural single carriageway A-roads is investigated and their predictive performance is evaluated against a recent data set. Despite the age of these models, the PAMs for predicting the total accidents provide a remarkably good fit to recent data and these are more accurate than models where accidents are disaggregated by type. The performance of the models can be improved by calibrating them against recent data
Recommended from our members
Future of an ageing population evidence review; Developing medical fitness and wellbeing environments to maintain health and wellbeing over the lifecourse.
Background and methods
This report is derived from a review of the research evidence on physical activity interventions
and initiatives, interventions to support self-management/ self-care of long-term conditions and
digitally enabled care services and technologies. The aim was to use existing evidence to
envision future services and associated infrastructure.
The Evidence Review involved scoping the literature for topics researched and to determine the
nature of that research. Rapid-scoping review methods were applied to trusted sources, and
searches for specific key texts were conducted. A separate search was conducted to identify
literature relevant to each domain. A narrative was then produced from the review findings.
Review findings
The evidence base for physical activity interventions is growing. There has been significant
recent investment in the development and evaluation of interventions to promote activity and
reduce sedentary behaviour at the individual, community and population levels. The evidence to
link higher levels of physical activity to positive health outcomes and disease prevention is
convincing, both in âwellâ populations and in those with long-term health conditions.
Self-management interventions are heterogeneous in nature but common elements exist across
the majority of them. The consensus in the literature is that self-management will become
increasingly important due to unsustainable demands upon services. Evaluation of selfmanagement
interventions reveals a small but varying effect across a wide range of outcomes.
However, little is known about the mechanisms by which these interventions work and how
these might vary across differing conditions and populations.
Technology is being increasingly used to support service delivery in a wide range of contexts,
and for the delivery of a variety of interventions including fitness and self-management. There is
strong evidence supporting the use of technology for remote monitoring of people with longterm
conditions, but further research is required.
Implications
Digital applications are already altering established patterns of service delivery. The findings
presented here reveal varying results of efficacy which do not accord with the optimistic future
described in various envisaging reports. Research has yet to consider unwanted and
unforeseen effects of moving towards technology-enabled services. It is also important to
consider how to effectively harness new health data emerging from the use of eHealth systems,
technology-enabled services and health-tracking devices.
There is an ongoing requirement to evaluate new technologies and technology-enabled
services in ways that provide both timely and robust answers, particularly as technology
development is a continually moving target. These considerations are discussed in this report
Recommended from our members
Assistive Technology: Creating and Engaging Collaborative Communities.
This paper outlines the remit of the UK Engineering and Physical Sciences Research Council KT-EQUAL (Knowledge Transfer for Extending Quality of Life for older and disabled people) programme. Case examples drawing on the range of activities undertaken by KT-EQUAL highlight where assistive technology developments have been facilitated, the value of network activities and an underpinning model of engagement and collaboration. Given an increasing emphasis on the impact of research the model and innovative approaches deployed by KT-EQUAL are even more crucial in future developments which aim to ensure that research can be used to benefit society
Circulation near the Newfoundland Ridge
Mesoscale eddies (25 to 150 km diameter) are observed to occur along the crest of the Newfoundland Ridge and have water properties that suggest an origin near the Tail of the Bank. The eddies appear to be important features of the circulation over the Ridge...
Bottom waters of the Gulf of Maine, 1978-1983
The properties of the bottom waters (\u3e100 m) of the Gulf of Maine are described using hydrographic data from 26 surveys between May 1978 and December 1983. The average temperature and salinity of the bottom water are presented from the different surveys for four regions of the GulfâWilkinson, Jordan, and Georges Basins and the Northeast Channel. The spatial variability across the Gulf was larger than the temporal variability in any region. The bottom water originates from Slope Water that enters the Gulf through the Northeast Channel. It is modified within the Gulf by vertical mixing with the near-surface waters of Scotian Shelf origin. A box model for the property changes during the summer-fall period indicates that the advection and mixing processes are of approximately equal importance in determining the bottom water properties. A winter convective input to the bottom layers is shown to occur only from the coastal areas around Wilkinson Basin in years when the surface salinity there was relatively high (\u3e33.0â°). Advection and mixing rates calculated by the box model are in agreement with direct measurements of the inflow to the Gulf (Ramp et al., 1985) and mixing estimates from a budget for the intermediate layer waters in the Gulf (Hopkins and Garfield, 1979)
The Cleo III Ring Imaging Cherenkov Detector
The CLEO detector has been upgraded to include a state of the art particle
identification system, based on the Ring Imaging Cherenkov Detector (RICH)
technology, in order to take data at the upgraded CESR electron positron
collider. The expected performance is reviewed, as well as the preliminary
results from an engineering run during the first few months of operation of the
CLEO III detector.Comment: 5 pages, 2 Figures Talk given by M. Artuso at 8th Pisa Meeting on
Advanced Detectors, May 200
Unexpected Effect of Internal Degrees of Freedom on Transverse Phonons in Supercooled Liquids
We show experimentally that in a supercooled liquid composed of molecules
with internal degrees of freedom the internal modes contribute to the frequency
dependent shear viscosity and damping of transverse phonons, which results in
an additional broadening of the transverse Brillouin lines. Earlier, only the
effect of internal modes on the frequency dependent bulk viscosity and damping
of longitudinal phonons was observed and explained theoretically in the limit
of weak coupling of internal degrees of freedom to translational motion. A new
theory is needed to describe this new effect. We also demonstrate, that the
contributions of structural relaxation and internal processes to the width of
the Brillouin lines can be separated by measurements under high pressure
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