Testing Models of Intrinsic Brightness Variations in Type Ia Supernovae, and their Impact on Measuring Cosmological Parameters

For spectroscopically confirmed Type Ia supernovae we evaluate models of intrinsic brightness variations with detailed data/Monte Carlo comparisons of the dispersion in the following quantities: Hubble-diagram scatter, color difference (B-V-c) between the true B-V color and the fitted color (c) from the SALT-II light curve model, and photometric redshift residual. The data sample includes 251 ugriz light curves from the 3-season Sloan Digital Sky Survey-II, and 191 griz light curves from the Supernova Legacy Survey 3-year data release. We find that the simplest model of a wavelength-independent (coherent) scatter is not adequate, and that to describe the data the intrinsic scatter model must have wavelength-dependent variations. We use Monte Carlo simulations to examine the standard approach of adding a coherent scatter term in quadrature to the distance-modulus uncertainty in order to bring the reduced chi2 to unity when fitting a Hubble diagram. If the light curve fits include model uncertainties with the correct wavelength dependence of the scatter, we find that the bias on the dark energy equation of state parameter $w$ is negligible. However, incorrect model uncertainties can lead to a significant bias on the distance moduli, with up to ~0.05 mag redshift-dependent variation. For the recent SNLS3 cosmology results we estimate that this effect introduces an additional systematic uncertainty on $w$ of ~0.02, well below the total uncertainty. However, this uncertainty depends on the samples used, and thus this small $w$-uncertainty is not guaranteed in future cosmology results.Comment: accepted by Ap

The Right to Counsel in Illinois: Evaluation of Adult Criminal Trial-Level Indigent Defense Services

This study shows there are two overarching reasons why the State of Illinois is defaulting on its constitutional right to counsel obligations. First, the state requires counties and courts to provide and predominantly fund indigent defense systems in a way that bakes in governmental interference with the right to counsel. Second, as one of only seven states with no state-level mechanism to oversee any aspect of trial-level right to counsel services, Illinois lacks information about every aspect of the varied indigent defense systems implemented by the county governments and courts in their efforts to fulfill the Sixth Amendment right to counsel responsibilities that the state has delegated to them. There is a path forward, and it is important for Illinois to get this right

Use of Exploratory Factor Analysis to Identify Factors Influencing Safety Climate in Two Work Environments

Safety climate as used in this research was first formally defined by Zohar (1980) through a research study which encompassed 20 Israeli factories across a variety of industries as “a summary of molar perceptions that employees share about their work environment” (pg 96). The term safety climate has been conceptualized as employees’ shared perceptions of how safety practices, policies, and procedures are implemented and prioritized, compared to other priorities such as productivity (Smith et al., 2005). Safety climate can further be conceptualized as a view of the state of safety in the organization at a discrete point in time, which may change over time (Cheyne et al., 1998; Cooper and Phillips, 2004; Neal, Griffin, and Hart, 2000; Guldenmund, 2000; Zohar, 1980, 2000, 2002a, 2002b).The paper, "Use of exploratory factor analysis to identify factors influencing safety climate in two work environments." (Jon L.P. Judge, Gretchen A. Mosher, and Stephen Simpson) JTMAE 35/2, April-June 2019, is a copyrighted publication of ATMAE. This paper has been republished with the authorization of ATMAE, and may be accessed directly from the JTMAE website at https://cdn.ymaws.com/www.atmae.org/resource/resmgr/jtmae/Use_of_Exploratory_Factor_An.pdf</p

Seventy questions of importance to the conservation of the North Central grasslands of the United States in a changing climate

Abstract Successful conservation of ecosystems in a changing climate requires actionable research that directly supports the rethinking and revising of management approaches to address changing risks and opportunities. As an important first step toward actionable research, we reviewed and synthesized grassland management‐related documents to identify broadly shared questions that, if answered, would help to support collective conservation of the grasslands in the northern Great Plains of the United States in a changing climate. A Management Priorities Working Group reviewed 183 grassland‐relevant management documents and identified 70 questions. Feedback was iteratively provided by a Climate and Ecology Working Group, an Advisory Committee, and representatives from grassland management agencies and organizations. The identified questions generally fall under 15 topics: land conversion; restoration; disturbance regimes; woody encroachment; herbaceous invasives; grazing; water quality, quantity, and availability; animal species; private land; public understanding; legal and policy changes; economic incentives; coordination across management entities; accessibility of science and tools; and novel ways of thinking. These questions can inform a research agenda for researchers looking to conduct actionable science in the Great Plains grassland ecosystems. Both the approach and the questions presented here can also be adapted and applied in other regions and ecosystems