The Michigan Disability Prevention Study: Research Highlights

This 3-year collaborative research project was designed to provide empirical evidence to substantiate the impact of various employer policies and practices on the prevention and management of workplace disability. It studied a random sample of 220 Michigan establishments with more than 100 employees from seven different industries who responded to a mail survey in the first half of 1991. The study correlates differences in employer-reported levels of achievement on policy and practice dimensions with performance on disability outcome measures, while controlling for a set of establishment characteristics in a multivariate regression analysis. There are three sets of policy and practice interventions evaluated here. First is safety intervention, that is, the attempt to prevent injuries from happening at all (measured as Safety Diligence, Ergonomic Solutions, and Safety Training). Second is disability management, the set of strategies to minimize the disability consequences of a given injury or disease arising from the workplace (measured as Disability Case Monitoring and Proactive Return-to-Work Program). Third is health promotion, which represents an attempt to intervene directly with individuals to encourage more healthy lifestyles, in the expectation that this will reduce the likelihood of a workplace accident or disease, or reduce the lost worktime resulting from a given injury or disease (measured as Wellness Orientation). In addition, a fourth dimension was included to capture the general environment of the firm and the orientation of its management in areas relevant to the study (measured as People Oriented Culture and Active Safety Leadership). These interventions and the general environment of the firm were scored on this set of eight variables which represent self-rated firm achievement of the policy and practice dimensions. The marginal effect of these interventions is determined by comparing firm performance on the incidence of work-related disability (Lost Workday Cases and Workers' Compensation Wage-Loss Claims), the duration of disability (Lost Workdays per Case), and overall disability prevention and management performance (Total Lost Workdays). Our results show that a higher self-rating on Safety Diligence is strongly associated with better performance on disability outcomes, varying with the specific measure. Higher self-rating on Proactive Return-to-Work Programs is also strongly associated with better performance outcomes. Safety Training and Active Safety Leadership is shown to have significant effects on the number of Lost Workday Cases. For example, on the summary measure of total Lost Workdays per 100 Employees, 10 percent better self-rating on Safety Diligence translates into 17 percent fewer lost workdays, and 10 percent better self-rating on Proactive Return-to-Work Programs translates into 7 percent fewer lost workdays. Thus, the twin strategies of trying to prevent injuries in the first place, and working to ameliorate their disability effects through disability management techniques, are both shown to be productive in reducing workplace disability in those establishments that have implemented them rigorously. Disability Case Monitoring could not be shown to have significant effects; in fact, Disability Case Monitoring had negative impacts in some cases. This probably reflects the controlling aspects of Disability Case Monitoring, as we speculate that these practices can be viewed by the employees as negative and interfering if they do not emanate from a supportive company human resource climate. Ergonomic Solutions and Wellness Orientation generally do not perform significantly, and this is attributed to their indirect connection to the performance outcomes used here or ineffective measurement of these dimensions in the study. Site visits were made to a subsample of 32 firms selected from the larger, random sample in order to confirm the quantitative survey findings and gain operational understanding of successful policies and practices contributing to low disability rates. Companies were generally found to be most advanced in their safety efforts, very active in injury management, and had implemented at least some form of return-to-work. Health promotion strategies to prevent specific work injuries have not yet been fully developed. The disability prevention efforts of successful firms use data effectively to measure performance, identify problems, guide actions taken, and motivate active support and participation of management, supervisors and line employees. Successful firms rigorously investigate injuries and communicate their commitment by immediately responding to risks when they are identified. In these low-disability firms, safety and disability management are viewed as components of quality, productivity and financial stability. Working relationships have been developed with responsive health care providers to assure effective injury management, but firms also maintain an active role in case management themselves. Their return-to-work process is systematic, yet flexible to respond to individual needs. Innovative firms have also implemented ergonomic principles to prevent risks. Nearly all companies visited reported increasing incidence and costs due to cumulative trauma and repetitive motion disorders. Additional strategies are needed to resolve and prevent these disabilities. This study demonstrates that many employers have moved aggressively to policies and practices designed to reduce the incidence and the costs of disability in their workplace. The project concludes that disability can be prevented and managed; and those who do it well can expect to be rewarded with lower disability costs, more satisfied workers, higher productivity and, ultimately, higher profits.disability, workers', compensation, Michigan, Hunt, Habeck

Disability Prevention Among Michigan Employers

This chapter briefly discusses the magnitude of the problem of disability in the workplace. It also presents an overview of the three and one-half year research project for which this Final Report is the product. It highlights the origins of the project and the major design elements that are reflected in this report. It concludes with a discussion of the remaining limitations of the research

Employer Factors in the Incidence and Cost of Workers\u27 Compensation Claims

Examines the correlates of workers\u27 compensation claims incidence and costs for a select sample of Michigan employers in 198

K3-fibered Calabi-Yau threefolds I, the twist map

A construction of Calabi-Yaus as quotients of products of lower-dimensional spaces in the context of weighted hypersurfaces is discussed, including desingularisation. The construction leads to Calabi-Yaus which have a fiber structure, in particular one case has K3 surfaces as fibers. These Calabi-Yaus are of some interest in connection with Type II -heterotic string dualities in dimension 4. A section at the end of the paper summarises this for the non-expert mathematician.Comment: 31 pages LaTeX, 11pt, 2 figures. To appear in International Journal of Mathematics. On the web at http://personal-homepages.mis.mpg.de/bhunt/preprints.html , #

On the structure of the energy distribution function in the hopping regime

The impact of the dispersion of the transport coefficients on the structure of the energy distribution function for charge carriers far from equilibrium has been investigated in effective-medium approximation for model densities of states. The investigations show that two regimes can be observed in energy relaxation processes. Below a characteristic temperature the structure of the energy distribution function is determined by the dispersion of the transport coefficients. Thermal energy diffusion is irrelevant in this regime. Above the characteristic temperature the structure of the energy distribution function is determined by energy diffusion. The characteristic temperature depends on the degree of disorder and increases with increasing disorder. Explicit expressions for the energy distribution function in both regimes are derived for a constant and an exponential density of states.Comment: 16 page

Structure of 10N in 9C+p resonance scattering

The structure of exotic nucleus 10N was studied using 9C+p resonance scattering. Two L=0 resonances were found to be the lowest states in 10N. The ground state of 10N is unbound with respect to proton decay by 2.2(2) or 1.9(2) MeV depending on the 2- or 1- spin-parity assignment, and the first excited state is unbound by 2.8(2) MeV.Comment: 6 pages, 4 figures, 1 table, submitted to Phys. Lett.

Induction techniques that reduce redistribution hypothermia: a prospective, randomized, controlled, single blind effectiveness study.

BACKGROUND: While much effort has been devoted to correcting intraoperative hypothermia, less attention has been directed to preventing redistribution hypothermia. In this study, we compared three different anesthetic induction techniques to standard IV propofol inductions (control) in their effect on reducing redistribution hypothermia. METHODS: Elective, afebrile patients, age 18 to 55 years, were randomly assigned to one of four groups (n = 50 each). Group INH/100 was induced with 8% sevoflurane in 100% oxygen, Group INH/50 with 8% sevoflurane in 50% oxygen and 50% nitrous oxide, Group PROP with 2.2 mg/kg propofol, and Group Phnl/PROP with 2.2 mg/kg propofol immediately preceded by 160 mcg phenylephrine. Patients were maintained with sevoflurane in 50% nitrous oxide and 50% oxygen in addition to opioid narcotic. Forced air warming was used. Core temperatures were recorded every 15 min after induction for 1 h. RESULTS: Compared to control group PROP, the mean temperatures in groups INH/100, INH/50, and Phnl/PROP were higher 15, 30, 45 and 60 min after induction (p \u3c 0.001 for all comparisons), averaging between 0.39 °C and 0.54 °C higher. In group PROP, 60% of patients had at least one temperature below 36.0 °C in the first hour whereas only 16% did in each of groups INH/100, INH/50, and Phnl/PROP (p \u3c 0.0001 in each group compared to PROP). CONCLUSIONS: In this effectiveness trial, inhalation inductions with sevoflurane or with prophylactic phenylephrine bolus prior to propofol induction reduced the magnitude of redistribution hypothermia by an average of 0.4 to 0.5 °C in patients aged 18 to 55 years. TRIAL REGISTRATION: Retrospectively registered on clinical-trials.gov as NCT02331108 , November 20, 2014

Dynamical Friction in a Gaseous Medium

Using time-dependent linear perturbation theory, we evaluate the dynamical friction force on a massive perturber M_p traveling at velocity V through a uniform gaseous medium of density rho_0 and sound speed c_s. This drag force acts in the direction -\hat V, and arises from the gravitational attraction between the perturber and its wake in the ambient medium. For supersonic motion (M=V/c_s>1), the enhanced-density wake is confined to the Mach cone trailing the perturber; for subsonic motion (M<1), the wake is confined to a sphere of radius c_s t centered a distance V t behind the perturber. Inside the wake, surfaces of constant density are hyperboloids or oblate spheroids for supersonic or subsonic perturbers, respectively, with the density maximal nearest the perturber. The dynamical drag force has the form F_df= - I 4\pi (G M_p)^2\rho_0/V^2. We evaluate I analytically; its limits are I\to M^3/3 for M>1. We compare our results to the Chandrasekhar formula for dynamical friction in a collisionless medium, noting that the gaseous drag is generally more efficient when M>1 but less efficient when M<1. To allow simple estimates of orbit evolution in a gaseous protogalaxy or proto-star cluster, we use our formulae to evaluate the decay times of a (supersonic) perturber on a near-circular orbit in an isothermal \rho\propto r^{-2} halo, and of a (subsonic) perturber on a near-circular orbit in a constant-density core. We also mention the relevance of our calculations to protoplanet migration in a circumstellar nebula.Comment: 17 pages, 5 postscript figures, to appear in ApJ 3/1/9

The impact of temperature on insecticide toxicity against the malaria vectors Anopheles arabiensis and Anopheles funestus

BACKGROUND: It is anticipated that malaria elimination efforts in Africa will be hampered by increasing resistance to the limited arsenal of insecticides approved for use in public health. However, insecticide susceptibility status of vector populations evaluated under standard insectary test conditions can give a false picture of the threat, as the thermal environment in which the insect and insecticide interact plays a significant role in insecticide toxicity. METHODS: The effect of temperature on the expression of the standard WHO insecticide resistance phenotype was examined using Anopheles arabiensis and Anopheles funestus strains: a susceptible strain and the derived resistant strain, selected in the laboratory for resistance to DDT or pyrethroids. The susceptibility of mosquitoes to the pyrethroid deltamethrin or the carbamate bendiocarb was assessed at 18, 25 or 30 degrees C. The ability of the pyrethroid synergist piperonyl-butoxide (PBO) to restore pyrethroid susceptibility was also assessed at these temperatures. RESULTS: Temperature impacted the toxicity of deltamethrin and bendiocarb. Although the resistant An. funestus strain was uniformly resistant to deltamethrin across temperatures, increasing temperature increased the resistance of the susceptible An. arabiensis strain. Against susceptible An. funestus and resistant An. arabiensis females, deltamethrin exposure at temperatures both lower and higher than standard insectary conditions increased mortality. PBO exposure completely restored deltamethrin susceptibility at all temperatures. Bendiocarb displayed a consistently positive temperature coefficient against both susceptible and resistant An. funestus strains, with survival increasing as temperature increased. CONCLUSIONS: Environmental temperature has a marked effect on the efficacy of insecticides used in public health against important African malaria vectors. Caution must be exercised when drawing conclusions about a chemical's efficacy from laboratory assays performed at only one temperature, as phenotypic resistance can vary significantly even over a temperature range that could be experienced by mosquitoes in the field during a single day. Similarly, it might be inappropriate to assume equal efficacy of a control tool over a geographic area where local conditions vary drastically. Additional studies into the effects of temperature on the efficacy of insecticide-based interventions under field conditions are warranted