6,369 research outputs found
Geographic Mobility and the Costs of Job Loss
This paper uses data from the 1968 through 1997 survey waves of the Panel Study of Income Dynamics to analyze how the long-term costs of job loss vary by a workerâs post-displacement migration status. Results from the analysis show that those individuals who move within the first 2 years after a job loss experience lower earnings losses, lower reductions in hours worked, and smaller increases in time unemployed when compared to a group of displaced workers who are not geographically mobile during the early years following this life event. Workers who move within the first 2 years after displacement face a lower probability of homeownership when compared to their non-mobile counterparts. However, this lower probability is short-lived
Revenue Sharing and Player Salaries in Major League Baseball
This article analyzes how changes made to the revenue sharing agreement in the 2007 Major League Baseball collective bargaining agreement influenced the salaries of position players and pitchers. The tax rates associated with revenue sharing decreased following ratification of the 2007 agreement. Theoretically, these changes should increase playersâ marginal revenue product and, therefore, salaries. Results indicate that position players experienced an increase in salary following the 2007 agreement. Pitchersâ salaries also increased, but by a smaller amount. The effect of the 2007 agreement was different throughout the salary distribution for position players, but uniform throughout the distribution for pitchers
Growth history of fault-related folds and interaction with seabed channels in the toe-thrust region of the deep-water Niger delta
The deep-water fold and thrust belt of the southern Niger Delta has prominent thrusts and folds oriented perpendicular to the regional slope that formed as a result of the thin-skinned gravitational collapse of the delta above overpressured shale. The thrust-related folds have grown in the last 12.8 Ma and many of the thrusts are still actively growing and influencing the pathways of modern seabed channels. We use 3D seismic reflection data to constrain and analyse the spatial and temporal variation in shortening of four thrusts and folds having seabed relief in a study area of 2600 km2 size in 2200â3800 m water depth. Using these shortening measurements, we have quantified the variation in strain rates through time for both fault-propagation and detachment folds in the area, and we relate this to submarine channel response. The total amount of shortening on the individual structures investigated ranges from 1 to 4 km, giving a time-averaged maximum shortening rate of between 90 ± 10 and 350 ± 50 m/Myr (0.1 and 0.4 mm/yr). Fold shortening varies both spatially and temporally: The maximum interval shortening rate occurred between 9.5 Ma and 3.7 Ma, and has reduced significantly in the last 3.7 Ma. We suggest that the reduction in the Pliocene-Recent fold shortening rate is a response to the slow-down in extension observed in the up-dip extensional domain of the Niger Delta gravitational system in the same time interval. In the area dominated by the fault-propagation folds, the channels are able to cross the structures, but the detachment fold is a more significant barrier and has caused a channel to divert for 25 km parallel to the fold axis. The two sets of structures have positive bathymetric expressions, with an associated present day uphill slope of between 1.5° and 2°. However, the shorter uphill slopes of the fault-propagation folds and increased sediment blanketing allow channels to cross these structures. Channels that develop coevally with structural growth and that cross structures, do so in positions of recent strain minima and at interval strain rates that are generally less than â0.02 Maâ1 (â1 Ă 10â16 sâ1). However, the broad detachment fold has caused channel diversion at an even lower strain rate of c. â0.002 Maâ1 (â7 Ă 10â17 sâ1)
Safety Regulation in Professional Football: Empirical Evidence of Intended and Unintended Consequences
In response to increasing public awareness and negative long-term health effects of concussions, the National Football League implemented the âCrown-of-the-Helmet Ruleâ (CHR). The CHR imposes penalties on players who initiate contact using the top of the helmet. This paper examines the intended effect of this policy and its potential for unintended consequences. We find evidence supporting the intended effect of the policy- a reduction in weekly concussion reports among defensive players by as much as 32% (34% for all head and neck injuries), but also evidence of an increase in weekly lower extremity injury reports for offensive players by as much as 34%
Resonant photo-thermal conversion for sub-terahertz imaging
An original design of generic interest is proposed for fast imaging, in the field of sub-terahertz frequencies, by means of resonant coupling between an ultra-thin photo-thermal converter and a metallic grid upstream an infrared camera. The material is a sheet of polyimide material with a high content of absorptive carbon inclusions. We make use of the large difference between the IR and THz wavelengths in a quarter-wave planar geometry, to ensure a highly efficient and stable conversion process. A complete setup has been implemented for demonstration purposes, using the beam from a Gunn diode at 110Â GHz. Experimental results are in good agreement with the predictions from the numerical model, which helps to validate the concept and the requirements for geometrical adjustment
The Adoption and Management of Soil Conservation Practices in Haiti: The Case of Rock Walls
Farmers are usually reluctant to adopt measures to reduce the toll of soil erosion; and even when soil conservation structures are adopted, farmers fail to manage them. This study investigates factors that influence adoption and management of soil conservation structures in Fort-Jacques, Haiti. The results show that personal characteristics of farmers, institutional factors, such as local group membership, training in soil conservation, per capita income and size of farm influence soil conservation adoption in Forte-Jacques. Age, education, per capita household income, participation in local groups, the interaction of per capita household income and farmersâ age influence rock wall management.Resource /Energy Economics and Policy,
Comparison of Nurse Staffing Based on Changes in Unit-level Workload Associated with Patient Churn
Aim
This analysis compares the staffing implications of three measures of nurse staffing requirements: midnight census, turnover adjustment based on length of stay, and volume of admissions, discharges and transfers. Background
Midnight census is commonly used to determine registered nurse staffing. Unit-level workload increases with patient churn, the movement of patients in and out of the nursing unit. Failure to account for patient churn in staffing allocation impacts nurse workload and may result in adverse patient outcomes. Method(s)
Secondary data analysis of unit-level data from 32 hospitals, where nursing units are grouped into three unit-type categories: intensive care, intermediate care, and medical surgical. Result
Midnight census alone did not account adequately for registered nurse workload intensity associated with patient churn. On average, units were staffed with a mixture of registered nurses and other nursing staff not always to budgeted levels. Adjusting for patient churn increases nurse staffing across all units and shifts. Conclusion
Use of the discharges and transfers adjustment to midnight census may be useful in adjusting RN staffing on a shift basis to account for patient churn. Implications for nursing management
Nurse managers should understand the implications to nurse workload of various methods of calculating registered nurse staff requirements
Determinants of farmer adoption of organic production methods in the fresh-market produce sector in California: A logistic regression analysis
This research uses binomial and multinomial logistic regression models to identify the factors that influence farmers adoption of organic technology. Using a sample of 175 farmers growing fresh-market produce in three California counties, the first model examines farmers choice between conventional-only and organic-only production. The second model compares conventional-only and "dual-method" (combined conventional and organic) production, while the third model employs all three choices in a multinomial model. These results, which indicate that gross sales, direct marketing, number of crops and acres, farmer age, and computer usage are significant determinants, have implications on policies that regulate the organic foods sector.Production Economics,
The Effectiveness of the Chemical Perturbation Index for Monitoring Water Quality in Three Mixed-use Urban Watersheds, Knoxville, Tennessee
Landscape change within the United States has resulted in significant physical and chemical alteration of our nation\u27s surface waters. Many research projects have demonstrated that landscape features moderate or cause observed water quality conditions. Urbanization is a rapidly growing form of landscape change in the United States and ranks second to agriculture as a major cause of stream degradation. Understanding the effect of urbanization on surface waters is only one component of the larger issue of restoring and maintaining the integrity of urban stream water quality. Effective watershed management is a social process that requires the inclusion of local citizens and community alliances. To this end, communities need the tools to gather useful and interpretable data about water quality. The Chemical Perturbation Index (CPI) may potentially be an inexpensive and easily interpretable index of water quality parameters that may be able to characterize both spatial and temporal changes in stream chemistry due to urbanization. The primary purpose of this study is to test the usefulness of the Chemical Perturbation Index as a tool for urban water quality assessment. To gain insight into this question, I explored the ability of the CPI to describe differences in the water quality of three mixed-use urban watersheds: Third Creek, Second Creek, and Goose Creek in Knox County, Tennessee.
To explore the usefulness of the CPI for urban water quality monitoring, I compared the CPI to other methods of describing and determining water quality found in the literature. My research into the CPI\u27s effectiveness as a water quality monitoring tool yielded mixed results. Statistical measures of the individual components of the CPI correlated with changes in landscape and land use characteristics throughout the research subbasins. The CPI itself did not show a relationship with the landscape or land use characteristics within the subbasins, but did show a general relationship with geologic characteristics. Pollution indicators modeled using the Hydrologic Simulation Program Fortran (HSPF) also failed to correlate significantly with the CPI or to demonstrate clear relationships between simulated pollution indicators· and the individual components of the CPI. The lack of expected correlations between landscape and land use factors and many of my chemical measures raises several questions about water quality in urban watersheds.
While previous research has demonstrated a connection between water chemistry and land use, previous studies have generally been done in larger watersheds than those in my research. In smaller watersheds that are urbanized to a high degree, the relationship between the degree of urbanization and water quality may not be as strong. This suggests that the relationship between water chemistry and landscape alteration does not necessarily extend across threshold levels for watershed scale and amount of urbanization. The CPI reflected to geologic characteristics, suggesting that, in extensively urbanized watersheds, factors other than land use account for the observed differences in water quality
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