1,177 research outputs found
Banded Contracts, Mediating Institutions, and Corporate Governance: A Naturalist Analysis of Contractual Theories of the Firm
Fort and Noone relate business ethics to notions of transcendence found in nature and anthropology. They address the notion of contracts within corporate legal theory because contracts are used as a model both by those who advocate minimalist, agency business duties and by others who propound a broad business ethic
Experimental and numerical investigation of wire waveguides for therapeutic ultrasound angioplasty
Therapeutic ultrasound angioplasty is an emerging minimally invasive cardiovascular procedure for disrupting atherosclerotic lesions using small diameter wire waveguides. The lesions are damaged through a combination of direct ablation, pressure waves, cavitation and acoustic streaming caused by distal-tip displacements at ultrasonic frequencies.
Numerical and experimental methods are used to investigate the outputs of the wire waveguides during ultrasonic activation. A commercially available generator and acoustic horn are used in combination with Nickel-Titanium (NiTi) wire waveguides in this study. A laser sensor is used to measure the frequency and amplitude output of the distal tip of the wire waveguide, and this is compared to amplitude estimations obtained using an optical microscope. Power is observed to affect both amplitude and frequency.
Clinical devices will require long, flexible waveguides with diameters small enough to access the coronary arteries. A finite element model is used to design tapered sections in long wire waveguides in order to achieve low profile distal geometry, and improve ultrasonic wave transmission. These tapered sections reduce the wire waveguide diameter in two stages, firstly from 1 to 0.35mm and then from 0.35 to 0.2, while increasing the amplitude of the ultrasonic wave by factors of 2.85 and 1.75, respectively. The numerical model also showed damping could potentially be a significant problem in long untapered wire waveguides (>l.5m).
Experimental ablation trials were conducted using the tapered long wire waveguides, including assessment of the effect of various combinations of bend radii and bend angles. The waveguide was found to perform well, but increased power levels were required to transmit ultrasound through tortuous waveguide configurations
Rapid virological surveillance of community influenza infection in general practice
No abstract available
Supporting Special-Purpose Health Care Models via Web Interfaces
The potential of the Web, via both the Internet and intranets, to facilitate development of clinical information systems has been evident for some time. Most Web-based clinical workstations interfaces, however, provide merely a loose collection of access channels. There are numerous examples of systems for access to either patient data or clinical guidelines, but only isolated cases where clinical decision support is presented integrally with the process of patient care, in particular, in the form of active alerts and reminders based on patient data. Moreover, pressures in the health industry are increasing the need for doctors to practice in accordance with Âżbest practiceÂż guidelines and often to operate under novel health-care arrangements. We present the Care Plan On-Line (CPOL) system, which provides intranet-based support for the SA HealthPlus Coordinated Care model for chronic disease management. We describe the interface design rationale of CPOL and its implementation framework, which is flexible and broadly applicable to support new health care models over intranets or the Internet
Socioeconomic, psychological and demographic determinants of Australian baby boomers' financial planning for retirement
Aim: Research from around the Western World has shown that psychological, socioeconomic and demographic factors can influence levels of financial planning. This study aims to determine how these factors interrelate to predict planning outcomes. Method: Data from the Ageing Baby Boomers in Australia Study were used to examine the effects of multiple factors on financial planning for 709 employed Australians nearing retirement. Results: The results showed that higher income, future time perspective (FTP) and financial knowledge independently predicted levels of retirement planning. The effects of FTP and financial knowledge on financial planning were consistent across levels of socioeconomic status. Conclusions: While similar issues in financial planning appeared across socioeconomic status, a 'one size fits all' approach to retirement policy may not be effective. Instead, policy should be targeted towards the diverse needs of different groups. Raising public awareness of FTP and financial knowledge may provide a useful starting point
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Influence of Sea-Ice Anomalies on Antarctic Precipitation Using Source Attribution in the Community Earth System Model
We conduct sensitivity experiments using a general circulation model that has an explicit water source tagging capability forced by prescribed composites of pre-industrial sea-ice concentrations (SICs) and corresponding sea surface temperatures (SSTs) to understand the impact of sea-ice anomalies on regional evaporation, moisture transport and sourcereceptor relationships for Antarctic precipitation in the absence of anthropogenic forcing. Surface sensible heat fluxes, evaporation and column-integrated water vapor are larger over Southern Ocean (SO) areas with lower SICs. Changes in Antarctic precipitation and its source attribution with SICs have a strong spatial variability. Among the tagged source regions, the Southern Ocean (south of 50 S) contributes the most (40 %) to the Antarctic total precipitation, followed by more northerly ocean basins, most notably the South Pacific Ocean (27%), southern Indian Ocean (16 %) and South Atlantic Ocean (11 %). Comparing two experiments prescribed with high and low pre-industrial SICs, respectively, the annual mean Antarctic precipitation is about 150 Gt yr1 (or 6 %) more in the lower SIC case than in the higher SIC case. This difference is larger than the model-simulated interannual variability in Antarctic precipitation (99 Gt yr1). The contrast in contribution from the Southern Ocean, 102 Gt yr1, is even more significant compared to the interannual variability of 35 Gt yr1 in Antarctic precipitation that originates from the Southern Ocean. The horizontal transport pathways from individual vapor source regions to Antarctica are largely determined by large-scale atmospheric circulation patterns. Vapor from lower-latitude source regions takes elevated pathways to Antarctica. In contrast, vapor from the Southern Ocean moves southward within the lower troposphere to the Antarctic continent along moist isentropes that are largely shaped by local ambient conditions and coastal topography. This study also highlights the importance of atmospheric dynamics in affecting the thermodynamic impact of sea-ice anomalies associated with natural variability on Antarctic precipitation. Our analyses of the seasonal contrast in changes of basin-scale evaporation, moisture flux and precipitation suggest that the impact of SIC anomalies on regional Antarctic precipitation depends on dynamic changes that arise from SICSST perturbations along with internal variability. The latter appears to have a more significant effect on the moisture transport in austral winter than in summer
Single particle analysis of ice crystal residuals observed in orographic wave clouds over Scandinavia during INTACC experiment
International audienceIndividual ice crystal residual particles collected over Scandinavia during the INTACC (INTeraction of Aerosol and Cold Clouds) experiment in October 1999 were analyzed by Scanning Electron Microscopy (SEM) equipped with Energy-Dispersive X-ray Analysis (EDX). Samples were collected onboard the British Met Office Hercules C-130 aircraft using a Counterflow Virtual Impactor (CVI). This study is based on six samples collected in orographic clouds. The main aim of this study is to characterize cloud residual elemental composition in conditions affected by different airmasses. In total 609 particles larger than 0.1 ?m diameter were analyzed and their elemental composition and morphology were determined. Thereafter a hierarchical cluster analysis was performed on the signal detected with SEM-EDX in order to identify the major particle classes and their abundance. A cluster containing mineral dust, represented by aluminosilicates, Fe-rich and Si-rich particles, was the dominating class of particles, accounting for about 57.5% of the particles analyzed, followed by low-Z particles, 23.3% (presumably organic material) and sea salt (6.7%). Sulfur was detected often across all groups, indicating ageing and in-cloud processing of particles. A detailed inspection of samples individually unveiled a relationship between ice crystal residual composition and airmass origin. Cloud residual samples from clean airmasses (that is, trajectories confined to the Atlantic and Arctic Oceans and/or with source altitude in the free troposphere) were dominated primarily by low-Z and sea salt particles, while continentally-influenced airmasses (with trajectories that originated or traveled over continental areas and with source altitude in the continental boundary layer) contained mainly mineral dust residuals. Comparison of residual composition for similar cloud ambient temperatures around ?27°C revealed that supercooled clouds are more likely to persist in conditions where low-Z particles represent significant part of the analyzed cloud residual particles. This indicates that organic material may be poor ice nuclei, in contrast to polluted cases when ice crystal formation was observed at the same environmental conditions and when the cloud residual composition was dominated by mineral dust. The presented results suggest that the chemical composition of cloud nuclei and airmass origin have a strong impact on the ice formation through heterogeneous nucleation in supercooled clouds
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