Three Systems of Workers' Compensation

Only three countries in the world maintain sub-national workers' compensation systems:Australia, Canada, and the United States. Three models are used to organize the insuranceresponsibilities for making the payments to injured or ill workers: private market, exclusivepublic insurer, and mixed (although the three models do not correspond exactly with the threecountries).All 10 Canadian provinces, 6 U.S. states, and 3 jurisdictions in Australia use the exclusive public insurer approach; the remaining 44 U.S. states and 4 jurisdictions in Australiause a predominately private market approach; and 3 Australian states use a mixed approach, in hich the public fund bears the underwriting risk, but private firms collect and disburse themoney.We will look at each of the three models, one from each country.1 Studying differentjurisdictions, even though from different nations, follows the tradition of using the "laboratory ofthe states" to inform policy decisions. We will describe the essential features of each system and then review system performance

Structure of unsteady stably stratified turbulence with mean shear.

The statistics of unsteady turbulence with uniform stratification N (Brunt–Väisälä frequency) and shear α(=dU1/dx3) are analysed over the entire time range (00 and \it Ri>0.25 respectively, oscillatory momentum and positive and negative density fluxes develop. Above a critical value of \it Ri\scriptsize\it crit(∼0.3), their average values are persistently countergradient. This structural change in the turbulence is the primary mechanism whereby stable stratification reduces the fluxes and the production of variances. It is quite universal and differs from the energy and stability mechanisms of Richardson (1926) and Taylor (1931). The long-time asymptotics of the energy ratio ER(=\it PE/VKE) of the potential energy to the vertical kinetic energy generally decreases with \it Ri(≥0.25), reaching the smallest value of 3/2 when there is no shear (\it Ri→∞). For strong mean shear (\it Ri<0.25), RDT significantly overestimates ER since (as in unstratified shear flow) it underestimates the vertical kinetic energy VKE. The RDT results show that the asymptotic values of the energy ratio ER and the normalized vertical density flux are independent of the initial value of ER, in agreement with DNS. This independence of the initial condition occurs because the ratios of the contributions from the initial values PE0 and KE0 are the same for PE and VKE and can be explained by the linear processes. Stable stratification generates buoyancy oscillations in the direction of the energy propagation of the internal gravity wave and suppresses the generation of turbulence by mean shear. Because the shear distorts the wavenumber fluctuations, the low-wavenumber spectrum of the vertical kinetic energy has the general form E33(k)∝(αtk)−1, where (LXαt)−1≪k≪L−1X (LX: integral scale). The viscous decay is controlled by the shear, so that the components of larger streamwise wavenumber k1 decay faster. Then, combined with the spectrum distortion by the shear, the energy and the flux are increasingly dominated by the small-k1 components as time elapses. They oscillate at the buoyancy period π/N because even in a shear flow the components as k1→0 are weakly affected by the shear. The effects of stratification N and shear α at small scales are to reduce both VKE and PE. Even for the same \it Ri, larger N and α reduce the high-wavenumber components of VKE and PE. This supports the applicability of the linear assumption for large N and α. At large scales, the stratification and shear effects oppose each other, i.e. both VKE and PE decrease due to the stratification but they increase due to the shear. We conclude that certain of these unsteady results can be applied directly to estimate the properties of sheared turbulence in a statistically steady state, but others can only be applied qualitatively

High resolution infrared absorption spectra of various trace gases present in the upper atmosphere of the Earth

The objective of NASA Grant NsG 7473 was to obtain and analyze high resolution infrared absorption spectra of various trace gases present in the Earth's upper atmosphere. The goal of the spectral analysis was to obtain values of absorption line strengths, widths and frequencies of sufficient accuracy for use in upper atmosphere trace gas monitoring. During the early phase of the grant, high resolution spectra were obtained from two instruments. One was the 0.02/cm resolution vacuum grating spectrometer at the Florida State University and the other was the 0.01/cm resolution Fourier transform spectrometer at the McMath solar telescope at the Kitt Peak Observatory. Using these instruments, a considerable amount of spectra of methane and hydrogen peroxide were obtained and analyzed. During the latter years of the project, data taking was halted while efforts were devoted to building a new 0.0025/cm resolution vacuum Fourier transform spectrometer. Progress during this phase of the grant then became greatly slowed due to a lack of suitable graduate students in the program. However, the instrument was completed and brought to the point of producing interferograms

The role of dust in "active" and "passive" low-metallicity star formation

We investigate the role of dust in star formation activity of extremely metal-poor blue compact dwarf galaxies (BCDs). Observations suggest that star formation in BCDs occurs in two different regimes: "active" and "passive". The "active" BCDs host super star clusters (SSCs), and are characterised by compact size, rich H2 content, large dust optical depth, and high dust temperature; the "passive" BCDs are more diffuse with cooler dust, and lack SSCs and large amounts of H2. By treating physical processes concerning formation of stars and dust, we are able to simultaneously reproduce all the above properties of both modes of star formation (active and passive). We find that the difference between the two regimes can be understood through the variation of the "compactness" of the star-forming region: an "active" mode emerges if the region is compact (with radius \la 50 pc) and dense (with gas number density \ga 500 cm$^{-3}$). The dust, supplied from Type II supernovae in a compact star-forming region, effectively reprocesses the heating photons into the infrared and induces a rapid H2 formation over a period of several Myr. This explains the high infrared luminosity, high dust temperature, and large H2 content of active BCDs. Moreover, the gas in "active" galaxies cools (\la 300 K) on a few dynamical timescales, producing a "run-away" star formation episode because of the favourable (cool) conditions. The mild extinction and relatively low molecular content of passive BCDs can also be explained by the same model if we assume a diffuse region (with radius \ga 100 pc and gas number density \la 100 cm$^{-3}$). We finally discuss primordial star formation in high-redshift galaxies in the context of the "active" and "passive" star formation scenario.Comment: Astronomy and Astrophysics, in press, 16 pages, 8 figure

The size--density relation of extragalactic HII regions

We investigate the size--density relation in extragalactic HII regions, with the aim of understanding the role of dust and different physical conditions in the ionized medium. First, we compiled several observational data sets for Galactic and extragalactic HII regions and confirm that extragalactic HII regions follow the same size (D)--density (n) relation as Galactic ones. Motivated by the inability of static models to explain this, we then modelled the evolution of the size--density relation of HII regions by considering their star formation history, the effects of dust, and pressure-driven expansion. The results are compared with our sample data whose size and density span roughly six orders of magnitude. We find that the extragalactic size--density relation does not result from an evolutionary sequence of HII regions but rather reflects a sequence with different initial gas densities (``density hierarchy''). Moreover, the size of many HII regions is limited by dust absorption of ionizing photons, rather than consumption by ionizing neutral hydrogen. Dust extinction of ionizing photons is particularly severe over the entire lifetime of compact HII regions with typical gas densities of greater than 10^3 cm^{-3}. Hence, as long as the number of ionizing photons is used to trace massive star formation, much star-formation activity could be missed. Such compact dense environments, the ones most profoundly obscured by dust, have properties similar to ``maximum--intensity starbursts''. This implies that submillimeter and infrared wavelengths may be necessary to accurately assess star formation in these extreme conditions both locally and at high redshift.Comment: 18 pages, 11 figures, accepted for publication in Astronomy and Astrophysic

New results in feedback control of unsupported standing in paraplegia

The aim of this study was to implement a new approach to feedback control of unsupported standing and to evaluate it in tests with an intact and a paraplegic subject. In our setup, all joints above the ankles are braced and stabilizing torque at the ankle is generated by electrical stimulation of the plantarflexor muscles. A previous study showed that short periods of unsupported standing with a paraplegic subject could be achieved. In order to improve consistency and reliability and to prolong the duration of standing, we have implemented several modifications to the control strategy. These include a simplified control structure and a different controller design method. While the reliability of standing is mainly limited by the muscle characteristics such as reduced strength and progressive fatigue, the results presented here show that the new strategy allows much longer periods (up to several minutes) of unsupported standing in paraplegia

Workers' Compensation Insurance In North America: Lessons for Victoria?

Among the issues we will consider here are the following. Who carries the underwriting(insurance) risk for workers' compensation benefits? How is workers' compensation insuranceprices, and by whom? What fundamental principles guide the insurance pricing system? Whomonitors benefits for compliance with statutory requirements? Are the availability of coverageand the payment of insurers' claims obligations guaranteed? Is self-insurance allowed and, if so, for whom? How are incentives for prevention of accidents, and resulting workers' compensation claims, maintained? What is the performance of the overall system? In summary, how are these questions answered and what so the answers reveal about how these responsibilities are allocated among government agencies, other public entities and private firms

Consumerism and well-being in early adolescence

It has been suggested that consumerism is negatively related to well-being in children and adolescents, as well as adults. Few studies have explored whether certain aspects of consumerism have stronger associations with well-being than others, or between-group differences in associations. This article uses data from a sample of early adolescents to examine: levels of consumerism; relationships between different aspects of consumerism and well-being; and differences according to gender, school year group and family affluence. Data were obtained in 2010 via secondary school pupil surveys (N=2934). Consumerism measures comprised number of ‘standard’ and ‘premium’ possessions and four dimensions of consumer involvement; well-being measures comprised self-esteem, psychological distress and anger. There was evidence of high penetration of consumerist values. There were positive associations between number of possessions and anger, and between ‘dissatisfaction’ and poorer well-being, regardless of how measured. ‘Brand awareness’ was associated with positive male well-being, but negative female well-being. Many relationships between consumerism and well-being were stronger than those between family affluence and well-being. These results suggest only certain aspects of consumerism are associated with poorer adolescent well-being. Although, for some sub-groups, other aspects might be associated with better well-being, there was no evidence that modern consumer goods promote happiness

Earnings Losses for Injured Workers

This article address the question "What proportion of all injured workers received adequate wage replacement?

Control of posture with FES systems

One of the major obstacles in restoration of functional FES supported standing in paraplegia is the lack of knowledge of a suitable control strategy. The main issue is how to integrate the purposeful actions of the non-paralysed upper body when interacting with the environment while standing, and the actions of the artificial FES control system supporting the paralyzed lower extremities. In this paper we provide a review of our approach to solving this question, which focuses on three inter-related areas: investigations of the basic mechanisms of functional postural responses in neurologically intact subjects; re-training of the residual sensory-motor activities of the upper body in paralyzed individuals; and development of closed-loop FES control systems for support of the paralyzed joints