The theory of Rational Addiction

The Theory of Rational Addictions, by Gary Becker & Kevin Murphy (1988), was a rational choice model that became a standard tool for economists modeling addictive behavior. The approach differs from other theories of addiction by modeling addictive behavior as the gradual implementation of a rational, forward‐looking plan, where consumption at any point in time is partly motivated by the immediate payoff of consumption and partly by the effects this consumption has on the individual in the future. This makes addictive behavior a subset of rational behavior, requiring no more specific government policies or attention than any other consumption choice. Later work by economists extended the theory in different ways, allowing it to match an increasing number of consumption patterns, and searched for ways to test the forward‐looking assumption in different types of market data. While the work was successful as a contribution to rational choice theory, with possible statistical applications, there are several reasons to dismiss its usefulness as an explanation of real‐world addictive behavior and its ability to assess the welfare effects of addictions.     

Focal spasticity therapy with botulinum toxin: effects on function, activities of daily living and pain in 100 adult patients.

OBJECTIVE: Analysis of the effects of a comprehensive focal spasticity program in adult patients. DESIGN: Retrospective study of an out-patient cohort. PATIENTS: One hundred patients were enrolled in the study (54 men and 46 women, mean age 41 years (SD 14). Cerebral palsy and stroke were equally common (80% in total). The remaining patients had miscellaneous diagnoses, including traumatic brain injury. METHODS: On average 230 units (SD 101) of botulinum toxin A Botox was given for 227 principal therapy targets chosen by the patient or the caregiver. One patient could have several targets for therapy. Administration of botulinum toxin was combined with 260 additional therapeutic interventions, most of which were forms of physical therapy. The effects were assessed after 6 weeks and compared with baseline functional abilities 1-2 weeks prior to therapy. RESULTS: Improvement was observed for 211 (93%) therapy targets, no change in 15 (7%), and impairment in 1, corresponding to an overall improvement in 90 patients (90%), 9 unchanged (9%) and worsening in 1. Spasticity assessment (Ashworth scale 0-4; 30 patients) showed a statistically significant improvement (median at baseline was 3 vs 2 after therapy, mean difference 1.2, p<0.001). CONCLUSION: Improvement was observed in >or=90% of patients and in their principal therapeutic targets in a cohort receiving their first focal spasticity treatment with botulinum toxin A and additional therapy. A strict strategy for patient selection and comprehensive management was followed.     

A virtual environment for surgical image guidance in intraoperative MRI.

Intraoperative MRI has recently entered the operating room as a new imaging modality. Customized visualization systems might further facilitate the use of this imaging technology. A visualization system for use in the interventional MRI has been developed, providing a virtual environment for surgical navigation using real-time images and for controlling the scanner. The visualization system has customized features for certain clinical applications. A training and testing facility has also been established. The introduction of the visualization system in the interventional MRI overcame several ambiguities and inconsistencies that were previously present, and resulted in a more transparent man-machine interface approach. A pilot study using the software to place cryoprobes in an animal liver showed promising results. Augmentation of real-time MR images with 3D rendering and customized navigation features opens new possibilities in intraoperative MRI. The described system can also be extended to other intraoperative imaging modalities.     

On the quantification of prothrombin from different species using echis carinatus as activator

The generation of thrombin-like activity from rat, human, bovine and mouse prothrombin by Echis carinatus venom (ECV) treatment was compared using a partially purified system (i.e. whole ECV and isolated prothrombin). A rapid increase in coagulant activity was obtained within 0.5 to 2 min., being constant upon further incubation for 60 min. A large variation in coagulant activity of the ECV generated thrombin from the four species was found, whereas no differences were found for the amidolytic activities. The coagulant activities of the ECV generated thrombin was also low compared with the corresponding thrombin activities obtained by physiological activation. Coagulant activity of the ECV generated thrombin levelled off at increasing concentration of prothrombin in the sample as measured by the one-stage coagulation assay. By measuring amidolytic activity a linear relationship to the concentration of prothrombin was found, however. These findings indicate that ECV converts prothrombin from the four different species to a thrombin-like protein with properties distinct from -thrombin. The lack of linearity in the ECV generated clot activity with increasing concentration of prothrombin could be explained by assuming a dimerization of the thrombin like protein molecules making them less accessible to fibrinogen. The significance of these observations for the quantification of prothrombin from different species is discussed.     

Validating the eating disorder inventory (EDI‐2) in two danish samples: A comparison between female eating disorder patients and females from the general population

The Eating Disorder Inventory, Version 2 (EDI‐2) is a questionnaire used clinically and in research all over the world. EDI‐2 is cross‐culturally valid, yet normative values may depend on culture. Norms and reliability of the Danish version have to date been lacking, and will be presented in this article, comparing patients (N = 575) and controls (N = 881). Also, internal reliability of scales is tested for both groups. Differences between norms of the Danish and the North American version of EDI were small but significant for all scales except asceticism (eating disorder patients) and ineffectiveness, interpersonal distrust and maturity fears (normal controls). For both groups the internal consistency was >0.70 for all subscales except asceticism. Although differences across the eating disorder diagnostic groups were dubious, the EDI‐2 is useful to screen for eating problems in the general population as well as to rate progress and outcome among eating disorder patients. Copyright © 2009 John Wiley & Sons, Ltd and Eating Disorders Association.