1,145 research outputs found
Economic evaluation of a community based exercise programme to prevent falls
OBJECTIVE: To assess the incremental costs and cost effectiveness of implementing a home based muscle strengthening and balance retraining programme that reduced falls and injuries in older women. DESIGN: An economic evaluation carried out within a randomised controlled trial with two years of follow up. Participants were individually prescribed an exercise programme (exercise group, n=116) or received usual care and social visits (control group, n=117). SETTING: 17 general practices in Dunedin, New Zealand. PARTICIPANTS: Women aged 80 years and older living in the community and invited by their general practitioner to take part. MAIN OUTCOME MEASURES: Number of falls and injuries related to falls, costs of implementing the intervention, healthcare service costs resulting from falls and total healthcare service costs during the trial. Cost effectiveness was measured as the incremental cost of implementing the exercise programme per fall event prevented. MAIN RESULTS: 27% of total hospital costs during the trial were related to falls. However, there were no significant differences in health service costs between the two groups. Implementing the exercise programme for one and two years respectively cost 265 (1995 New Zealand dollars) per fall prevented, and 426 per fall resulting in a moderate or serious injury prevented. CONCLUSIONS: The costs resulting from falls make up a substantial proportion of the hospital costs for older people. Despite a reduction in falls as a result of this home exercise programme there was no significant reduction in healthcare costs. However, the results reported will provide information on the cost effectiveness of the programme for those making decisions on falls prevention strategies
A comparison of the effectiveness of TiO2 photocatalysis and UVA photolysis for the destruction of three pathogenic micro-organisms.
TiO2 photocatalysis has demonstrated efficacy as a treatment process for water contaminated with chemical pollutants. When exposed to UVA light TiO2 also demonstrates an effective bactericidal activity. The mechanism of this process has been reported to involve attack by valence band generated hydroxyl radicals. In this study when three common bacterial pathogens, Escherichia coli, Salmonella enterica serovar Enteritidis and Pseudomonas aeruginosa, were exposed to TiO2 and UVA light a substantial decrease in bacterial numbers was observed. Control experiments in which all three pathogens were exposed to UVA light only resulted in a similar reduction in bacterial numbers. Moreover, exposure to UVA light alone resulted in the production of a smaller than average colony phenotype among the surviving bacteria, for all three pathogens examined, a finding which was not observed following treatment with UVA and TiO2. Small slow growing colonies have been described for several pathogenic bacteria and are referred to as small colony variants. Several studies have demonstrated an association between small colony variants and persistent, recurrent and antibiotic resistant infections. We propose that the production of small colony variants of pathogenic bacteria following UVA treatment of drinking water may represent a health hazard. As these small colony variants were not observed with the UVA/TiO2 system this potential hazard is not a risk when using this technology. It would also appear that the bactericidal mechanism is different with the UVA/TiO2 process compared to when UVA light is used alone
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Radial cutting torch
The project`s aim is to complete development of the Radial Cutting Torch, a pyrotechnic cutter, for use in all downhole tubular cutting operations in the petroleum industry. Project objectives are to redesign and pressure test nozzle seals to increase product quality, reliability, and manufacturability; improve the mechanical anchor to increase its temperature tolerance and its ability to function in a wider variety of wellbore fluids; and redesign and pressure test the RCT nozzle for operation at pressures from 10 to 20 ksi. The proposal work statement is included in the statement of work for the grant via this reference
A Compact 3H(p,gamma)4He 19.8-MeV Gamma-Ray Source for Energy Calibration at the Sudbury Neutrino Observatory
The Sudbury Neutrino Observatory (SNO) is a new 1000-tonne D2O Cerenkov solar
neutrino detector. A high energy gamma-ray source is needed to calibrate SNO
beyond the 8B solar neutrino endpoint of 15 MeV. This paper describes the
design and construction of a source that generates 19.8-MeV gamma rays using
the 3H(p,gamma)4He reaction (``pt''), and demonstrates that the source meets
all the physical, operational and lifetime requirements for calibrating SNO. An
ion source was built into this unit to generate and to accelerate protons up to
30 keV, and a high purity scandium tritide target with a scandium-tritium
atomic ratio of 1:2.0+/-0.2 was included. This pt source is the first
self-contained, compact, and portable high energy gamma-ray source (E>10 MeV).Comment: 33 pages (including 2 table, 12 figures) This is the revised
manuscript, accepted for publication in NIM A. This revision relfects minor
editorial changes from the previous versio
Particle-Like Description in Quintessential Cosmology
Assuming equation of state for quintessential matter: , we
analyse dynamical behaviour of the scale factor in FRW cosmologies. It is shown
that its dynamics is formally equivalent to that of a classical particle under
the action of 1D potential . It is shown that Hamiltonian method can be
easily implemented to obtain a classification of all cosmological solutions in
the phase space as well as in the configurational space. Examples taken from
modern cosmology illustrate the effectiveness of the presented approach.
Advantages of representing dynamics as a 1D Hamiltonian flow, in the analysis
of acceleration and horizon problems, are presented. The inverse problem of
reconstructing the Hamiltonian dynamics (i.e. potential function) from the
luminosity distance function for supernovae is also considered.Comment: 35 pages, 26 figures, RevTeX4, some applications of our treatment to
investigation of quintessence models were adde
Cosmic histories of star formation and reionization: An analysis with a power-law approximation
With a simple power-law approximation of high-redshift () star
formation history, i.e., , we
investigate the reionization of intergalactic medium (IGM) and the consequent
Thomson scattering optical depth for cosmic microwave background (CMB) photons.
A constraint on the evolution index is derived from the CMB optical
depth measured by the {\it Wilkinson Microwave Anisotropy Probe} (WMAP)
experiment, which reads ,
where the free parameter is the number of the escaped
ionizing ultraviolet photons per baryon. Moreover, the redshift for full
reionization, , can also be expressed as a function of as well as
. By further taking into account the implication of the
Gunn-Peterson trough observations to quasars for the full reionization
redshift, i.e., , we obtain
and .
For a typical number of of ionizing photons released per baryon of
normal stars, the fraction of these photons escaping from the stars, , can be constrained to within the range of .Comment: 10 pages, 4 figures, accepted for publication in JCA
Electronic structure and ferroelectricity in SrBi2Ta2O9
The electronic structure of SrBi2Ta2O9 is investigated from first-principles,
within the local density approximation, using the full-potential linearized
augmented plane wave (LAPW) method. The results show that, besides the large
Ta(5d)-O(2p) hybridization which is a common feature of the ferroelectric
perovskites, there is an important hybridization between bismuth and oxygen
states. The underlying static potential for the ferroelectric distortion and
the primary source for ferroelectricity is investigated by a lattice-dynamics
study using the Frozen Phonon approach.Comment: 17 pages, 7 figures. Phys. Rev. B, in pres
Reversible Band Gap Engineering in Carbon Nanotubes by Radial Deformation
We present a systematic analysis of the effect of radial deformation on the
atomic and electronic structure of zigzag and armchair single wall carbon
nanotubes using the first principle plane wave method. The nanotubes were
deformed by applying a radial strain, which distorts the circular cross section
to an elliptical one. The atomic structure of the nanotubes under this strain
are fully optimized, and the electronic structure is calculated
self-consistently to determine the response of individual bands to the radial
deformation. The band gap of the insulating tube is closed and eventually an
insulator-metal transition sets in by the radial strain which is in the elastic
range. Using this property a multiple quantum well structure with tunable and
reversible electronic structure is formed on an individual nanotube and its
band-lineup is determined from first-principles. The elastic energy due to the
radial deformation and elastic constants are calculated and compared with
classical theories.Comment: To be appear in Phys. Rev. B, Apr 15, 200
The social construction of male infertility: a qualitative questionnaire study of men with a male factor infertility diagnosis
Although recent research has highlighted the distressing impact of infertility for men, fertility issues are still routinely seen as a 'women's issue' - even when male factor infertility is highlighted. This article reports findings from a qualitative questionnaire study focusing on a sample of men with a male factor infertility diagnosis; an under-researched and marginalised group in the context of reproductive medicine. Our analysis suggests that male factor infertility is viewed by men as a failure of masculinity, as stigmatising and silencing, and as an isolating and traumatic experience. It is also clear that these themes are shaped by wider societal discourses which present men as (unproblematically) fertile, uninvested in parenthood and stoic in their approach to emotional distress. Such norms also ensure that reproduction continues to be presented as a 'women's issue' which burdens women and marginalises men. In understanding male factor infertility experiences, the damaging nature of the social construction of male fertility is then more clearly illuminated
The half-lives for 24Na, 72Ga and 140La
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22610/1/0000160.pd
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