A SAEM algorithm for the estimation of template and deformation parameters in medical image sequences

This paper is about object deformations observed throughout a sequence of images. We present a statistical framework in which the observed images are defined as noisy realizations of a randomly deformed template image. In this framework, we focus on the problem of the estimation of parameters related to the template and deformations. Our main motivation is the construction of estimation framework and algorithm which can be applied to short sequences of complex and highly-dimensional images. The originality of our approach lies in the representations of the template and deformations, which are defined on a common triangulated domain, adapted to the geometry of the observed images. In this way, we have joint representations of the template and deformations which are compact and parsimonious. Using such representations, we are able to drastically reduce the number of parameters in the model. Besides, we adapt to our framework the Stochastic Approximation EM algorithm combined with a Markov Chain Monte Carlo procedure which was proposed in 2004 by Kuhn and Lavielle. Our implementation of this algorithm takes advantage of some properties which are specific to our framework. More precisely, we use the Markovian properties of deformations to build an efficient simulation strategy based on a Metropolis-Hasting-Within-Gibbs sampler. Finally, we present some experiments on sequences of medical images and synthetic data.     

Training for efficiency: work, time, and systems-based practice in medical residency

Medical residency is a period of intense socialization with a heavy workload. Previous sociological studies have identified efficiency as a practical skill necessary for success. However, many contextual features of the training environment have undergone dramatic change since these studies were conducted. What are the consequences of these changes for the socialization of residents to time management and the development of a professional identity? Based on observations of and interviews with internal medicine residents at three training programs, we find that efficiency is both a social norm and strategy that residents employ to manage a workload for which the demand for work exceeds the supply of time available to accomplish it. We found that residents struggle to be efficient in the face of seemingly intractable "systems" problems. Residents work around these problems, and in doing so develop a tolerance for organizational vulnerabilities.     

Multisystemic Therapy for Disruptive Behavior Problems in Youths With Autism Spectrum Disorders: A Progress Report

Youths with autism spectrum disorders (ASD) often engage in serious disruptive behaviors that interfere with their ability to successfully manage day‐to‐day responsibilities and contribute to relationship problems with caregivers, peers, and teachers. Effective treatments are needed to address the factors linked with disruptive behavior problems in this population of youths. Multisystemic therapy (MST) is a comprehensive family‐ and community‐based treatment approach that has been effective with other difficult‐to‐treat populations of youths and holds promise for youths with ASD. In this article, we review the broad range of factors associated with disruptive behaviors among youths with ASD and discuss how MST interventions can be adapted to address those factors. We also present a framework for our adaptation of the MST model for youths with ASD. This framework includes a recently completed pilot study as well as an ongoing efficacy trial that together have served to identify key interventions for our adaptation of the MST model.     

The Family Context of Relational Aggression in “Difficult to Treat” Female Juvenile Offenders

Female juvenile offenders often engage in socially aggressive behaviors that make them more difficult to treat than male juvenile offenders. This social (i.e., relational) aggression may be developed or maintained through transactions with family members. To investigate this issue, we measured relational aggression in the family interactions of 140 adolescents divided by gender and offender status into four equal‐sized groups (female juvenile offenders, male juvenile offenders, female nonoffenders, and male nonoffenders). Adolescents and caregivers completed a family discussion task, and raters coded relationally aggressive behaviors at the dyadic level. Results showed that female juvenile offenders and their mothers directed more relational aggression toward each other than did mother–adolescent dyads in the other groups. Implications of these results for treatment and research are discussed.     

Austerity and the Demise of Social Europe: The Baltic Model versus the European Social Model

This article draws on the experience of the imposition of radical austerity measures in the Baltic states. It challenges the myth that austerity can be achieved in a socially and economically ‘costless’ manner. Baltic-style austerity has now become a template of ‘successful adjustment’ and a recipe for recovery of the Eurozone. The authors argue contra such ‘myth-making’ that austerity is compromising the longer run sustainability of societies that follow this path, while simultaneously ending prospects of the adhesion of a European ‘Social Model’ in the post-communist periphery. The article is a contribution to an emerging debate in academic and policy circles concerning the viability and future of Europe's ‘Social Model’ in an age of austerity.     

The Associations of Financial Stress and Parenting Support Factors with Alcohol Behaviors During Young Adulthood

This study examined concurrent and prospective associations of financial stress (financial strain, lack of financial access, public assistance) and parenting support factors (relationship quality, living at home, financial support) with young adults’ alcohol behaviors (alcohol use, heavy drinking, and problematic drinking) over a 5-year period. Analyses of National Longitudinal Study of Adolescent Health (Add Health) data (N = 7,159) showed that, over the study period, alcohol use and heavy drinking declined while problematic drinking increased. In addition, living at home and parental relationship quality were associated with fewer concurrent and prospective alcohol behaviors whereas financial strain and parents’ financial support were associated with more alcohol behaviors. The implications for minimizing alcohol misuse in young adults amid uncertain economic conditions are discussed.