Comparison of five approaches to keeping power line maintainers' hands warm during work in the cold

Electric utility workers in Canada must frequently work in the cold and must wear thick rubber gloves which can result in rapid fatigue and reduced performance. The purpose of the study was therefore to document the challenge of working in the cold wearing the standard five-finger rubber gloves and covers and compare them to two equipment options, mitten style gloves or a prototype wool liner, and two heating options, glove or torso heating. The dependent measures were grip force, temperature, dexterity (modified Purdue pegboard test and a simulated occupational task), finger sensitivity (Von Frey hair test), perceived effort and thermal sensation. The study population consisted of 10 experienced male utility workers. They worked in a controlled temperature walk-in chamber (-20 degrees Celsius) and performed simulated utility work for 45 minutes with interspersed test batteries. The mitten style glove and woolen liner in a standard glove reduced the effects of working in the cold compared to the standard five-fingered variety with a thin cotton liner. We found that the mitten style glove showed lesser drops in skin temperature for the 3rd and 5th digits than the other conditions (p < 0.05).     

A national evaluation of Safe Schools/Healthy Students: outcomes and influences

The Safe Schools/Healthy Students (SS/HS) Initiative has awarded over $2 billion in grants to more than 350 school districts in partnership with local mental health, law enforcement, and juvenile justice agencies. To estimate the impact of grantee characteristics, grant operations, and near-term outcomes in reducing violence and substance use, promoting mental health, and enhancing school safety, logged odds ratios (LORs) were calculated contrasting Year 3 with Baseline performance from grantee-provided data on seven outcome measures. After comparing grantee performance across outcomes and outcomes across grantees, the LORs were entered as dependent variables in a series of meta-regressions in which grantee characteristics, grant operations, and near-term outcomes were tested after controlling for pre-grant characteristics. Findings indicate that the SS/HS Initiative significantly improved most outcomes, that within-grantee performance varied greatly by outcome, and that random-effects meta-regression appreciably decreased the variance available for modeling. The approach demonstrates that the SS/HS Initiative is effective and that locally collected performance data can be used to estimate grantee success in improving youth outcomes.     

Sustainable Luxury Marketing: A Synthesis and Research Agenda

Sustainability has become a pervasive issue for the luxury sector, gaining traction with brand managers, scholars, policy‐makers, the media, and academia. The purpose of this paper is to examine the state of sustainable luxury research in marketing and consumer behaviour by critically reviewing and synthesizing the growing but fragmented body of scholarly work on sustainable‐luxury marketing. The paper critically assesses where, how and by whom research on sustainable luxury is being conducted, and it identifies gaps for future investigation. The paper reviews research published between 2007 and 2018 within major peer‐reviewed English‐language scholarly publications in business, marketing, ethics, fashion, food and tourism journals. The research is identified using the keywords sustainable luxury, green luxury, eco‐luxury and organic luxury. Three core themes emerge from this review: (1) consumer concerns and practices; (2) organizational concerns and practices; and (3) international and cross‐cultural issues. The review confirms that research on sustainable luxury is significantly underdeveloped. This paper provides the first critical and comprehensive assessment and categorization of the emergent literature streams on sustainable luxury. The authors argue for a broader, deeper and more critical research agenda on the relationship between sustainability and luxury. Potential avenues for future research on sustainable luxury are proposed, with calls for theoretical and cross‐cultural reflections that tackle broader systemic and institutional issues within the field.     

Mixture models, latent variables and partitioned importance sampling

Gibbs sampling has had great success in the analysis of mixture models. In particular, the “latent variable” formulation of the mixture model greatly reduces computational complexity. However, one failing of this approach is the possible existence of almost-absorbing states, called trapping states, as it may require an enormous number of iterations to escape from these states. Here we examine an alternative approach to estimation in mixture models, one based on a Rao–Blackwellization argument applied to a latent-variable-based estimator. From this derivation we construct an alternative Monte Carlo sampling scheme that avoids trapping states.     

Conditional Score Tests for Heteroscedasticity in the Two-Way Error Components Model

This paper extends the one-way heteroskedasticity score test of Holly and Gardiol (2000, In: Krishnakumar, J, Ronchetti, E (Eds.), Panel Data Econometrics: Future Directions, North-Holland, Amsterdam, pp. 199–211) to two conditional Lagrange Multiplier (LM) tests of heteroskedasticity under contiguous alternatives within the two-way error components model framework. In each case, the derivation of Rao's efficient score statistics for testing heteroskedasticity is first obtained. Then, based on a specific set of assumptions, the asymptotic distribution of the score under contiguous alternatives is established. Finally, the expression for the score test statistic in the presence of heteroskedasticity and related asymptotic local powers of these score test statistics are derived and discussed.     

Oversampling Through Households or Other Clusters: Comparisons of Methods for Weighting the Oversampled Elements

If a subgroup of a population is of particular interest in a survey, researchers may wish to increase the yield of this special subgroup by oversampling. One procedure for oversampling through households, or other clusters, is to divide the households into two segments: the main sample and the oversample (for which only members of the special group are eligible). Members of the oversampled special group come from both segments. This paper describes three methods for weighting the members of the special group. The household method treats the segments as strata and weights according to the proportion of households in each segment. The yield method uses weights according to the yield of special-group members in the two segments. The combined probability method provides a Horvitz-Thompson estimator using the sum of the probabilities that a person will be selected through either segment. Simulations show that the yield method produces estimates with variance lower than those of the household method. The combined probability method appears to be even more efficient. The difference in precision between the methods is small for estimates from the total sample but the household method can be markedly worse than the other two methods for estimates from the oversampled special group (over 40% greater variance in one scenario). Results from a community sample illustrate the comparisons. Because the household method can be much less efficient it should not be used.     

INCORPORATING SALES FORCE PREFERENCES IN A GOAL PROGRAMMING MODEL FOR THE SALES RESOURCE ALLOCATION PROBLEM

This note presents a model for the sales territory assignment and resource allocation problem. The integer-goal-programming model includes input from the sales representatives in the form of preference values along with organizational goal values from management. The approach integrates the multiple objectiive inputs both for individual sales reprresentatives and for the organization into a single model by employing the approaches of multiattribute utility theory and multicriteria decision making. The purpose of the model is to provide a vehicle for testing various strategies and assessing the impact of those strategies on the sales representatives’utilities and the organization's goals.