Predicting treatment efficacy via quantitative magnetic resonance imaging: a Bayesian joint model

The prognosis for patients with high grade gliomas is poor, with a median survival of 1 year. Treatment efficacy assessment is typically unavailable until 5-6 months post diagnosis. Investigators hypothesize that quantitative magnetic resonance imaging can assess treatment efficacy 3 weeks after therapy starts, thereby allowing salvage treatments to begin earlier. The purpose of this work is to build a predictive model of treatment efficacy by using quantitative magnetic resonance imaging data and to assess its performance. The outcome is 1-year survival status. We propose a joint, two-stage Bayesian model. In stage I, we smooth the image data with a multivariate spatiotemporal pairwise difference prior. We propose four summary statistics that are functionals of posterior parameters from the first-stage model. In stage II, these statistics enter a generalized non-linear model as predictors of survival status. We use the probit link and a multivariate adaptive regression spline basis. Gibbs sampling and reversible jump Markov chain Monte Carlo methods are applied iteratively between the two stages to estimate the posterior distribution. Through both simulation studies and model performance comparisons we find that we can achieve higher overall correct classification rates by accounting for the spatiotemporal correlation in the images and by allowing for a more complex and flexible decision boundary provided by the generalized non-linear model.     

Small-Sample Properties of GMM-Based Wald Tests

This article assesses the small-sample properties of generalized-method-of-moments-based Wald statistics by using (a) a vector white-noise process and (b) an equilibrium business-cycle model as the data-generating mechanisms. In many cases, the small-sample size of the Wald tests exceeds its asymptotic size and increases sharply with the number of hypotheses being jointly tested. We argue that this is mostly due to difficulty in estimating the spectral-density matrix of the residuals. Estimators of this matrix that impose restrictions implied by the model or the null hypothesis substantially improve the properties of the Wald statistics.     

Overwhelming Casualties: Medical Ethics in a Time of Terror

Codes of ethics and ethics guidelines define standards of professional conduct, and ways to prioritize or balance ethical principles when these appear to be in conflict. In 1991 an international and interdisciplinary group of scholars met at the University of Toronto to discuss these problems in a Workshop on Ethical Considerations in Scholarship and Science. A document, “The Toronto Resolution”; (TTR), was developed, providing twelve principles for incorporation into scientific and scholarly codes, with the object of ensuring that professionals in science recognize the potential consequences of their work in the broader social context. To examine the extent to which existing codes are consonant with The Toronto Resolution's 12 principles, a content analysis was conducted on the codes of 21 Ontario‐based scientific and scholarly organizations. Criteria used in the content analysis were standardized and determined to be reliable. Only a weak correspondence was found between the contents of the codes of the scientific and scholarly organizations surveyed here and the principles set out in TTR. In particular, guidelines on specific social issues such as environmental effects or conflict resolution are scarcely mentioned at all. This study encourages consideration of The Toronto Resolution by the ethics committees of scientific and scholarly associations, as codes are revised or as new interpretations of principles in the codes evolve.     

Metachoice for strategic analysis

A necessary precursor to strategic choice is the selection of a strategic choice evaluation method — metachoice. Unfortunately, managers are unlikely to find much guidance on how to conduct metachoice analysis in the strategy literature. In light of this problem, a template is presented based on two questions that must be addressed by those engaged in strategic analysis generally and metachoice specifically: (1) what are the organization's strategic goals? (2) how willing are they to monetize their predictions and valuations? Four resulting choice methods are presented and discussed: Discounted Cash Flow Analysis (including variants based on real options), Profitability Analysis, Modified Discounted Cash Flow Analysis and Multi-Goal Analysis.     

Promoting Self-Efficacy and Self-Esteem for Multiethnic Sexual Minority Youth: An Evidence-Informed Intervention

ABSTRACT

Sexual minority youth face multiple challenges, yet research regarding evidence-informed practice strategies for this population is limited. This study describes the pilot efforts of Strengths First, the first strengths-based intervention created specifically to promote self-esteem and self-efficacy among multiethnic sexual minority youth. A pretest–posttest design was used to gather preliminary data from program participants (n = 162) about the potential effectiveness of the program during a 2-year period that ranged from the inception of the program in June 2008 to September 2010. Significant increases in self-esteem and self-efficacy were found. Implications for social service research and practice are discussed.     

Coverage of Veterans of the Wars in Iraq and Afghanistan in the U.S. Media

To evaluate how the media frames veterans of the wars in Iraq and Afghanistan, this study systematically assesses the discourse on Iraq and Afghanistan veterans in the New York Times and Washington Post from 2003 to 2011. Our analysis of a stratified sample of 151 articles featuring veterans from either the wars in Iraq or Afghanistan finds that the media frames veterans as damaged by their service but deserving of government benefits and social assistance. When the media frames veterans as actively engaging in society, their social engagement is often because of or despite their injuries or mistreatment. We find interplay between victimization and deservingness such that depictions of the cohort as physically and mentally damaged complement and justify arguments for a sustained high level of benefits to accommodate the needs of veterans. We thus argue that generous benefits for veterans partly stem from their depiction as having suffered from their service.