Parameter estimate of signal transduction pathways

BACKGROUND: The "inverse" problem is related to the determination of unknown causes on the bases of the observation of their effects. This is the opposite of the corresponding "direct" problem, which relates to the prediction of the effects generated by a complete description of some agencies. The solution of an inverse problem entails the construction of a mathematical model and takes the moves from a number of experimental data. In this respect, inverse problems are often ill-conditioned as the amount of experimental conditions available are often insufficient to unambiguously solve the mathematical model. Several approaches to solving inverse problems are possible, both computational and experimental, some of which are mentioned in this article. In this work, we will describe in details the attempt to solve an inverse problem which arose in the study of an intracellular signaling pathway. RESULTS: Using the Genetic Algorithm to find the sub-optimal solution to the optimization problem, we have estimated a set of unknown parameters describing a kinetic model of a signaling pathway in the neuronal cell. The model is composed of mass action ordinary differential equations, where the kinetic parameters describe protein-protein interactions, protein synthesis and degradation. The algorithm has been implemented on a parallel platform. Several potential solutions of the problem have been computed, each solution being a set of model parameters. A sub-set of parameters has been selected on the basis on their small coefficient of variation across the ensemble of solutions. CONCLUSION: Despite the lack of sufficiently reliable and homogeneous experimental data, the genetic algorithm approach has allowed to estimate the approximate value of a number of model parameters in a kinetic model of a signaling pathway: these parameters have been assessed to be relevant for the reproduction of the available experimental data

The Impact of DSM-5 on Eating Disorder Diagnoses

ObjectiveEating disorder diagnostic criteria were revised from the fourth to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV and -5, respectively). This study examines the impact of these revisions on rates of eating disorder diagnoses in treatment-seeking youth.MethodParticipants were 651 youth, ages 7-18 years, presenting to an outpatient eating disorders program who met criteria for a DSM-IV eating disorder diagnosis on intake. Patients completed well-validated semi-structured interviews to assess eating disorder psychopathology and psychiatric comorbidity.ResultsParticipants were predominantly female (n = 588; 90.3%) with an average age of 15.28 years (SD = 2.21), mean percent of median Body Mass Index (mBMI) of 101.91 (SD = 31.73), and average duration of illness of 16.74 months (SD = 17.63). Cases of DSM-IV Eating Disorder Not Otherwise Specified (EDNOS), now most consistent with DSM-5 Other Specified Feeding or Eating Disorder, decreased from 47.6% to 39.0%, Anorexia Nervosa increased from 29.6% to 33.5%, and Bulimia Nervosa increased from 22.7% to 24.7%.DiscussionConsistent with previous studies, and in keeping with the aims of the DSM-5 for eating disorders, the revised diagnostic criteria reduced cases of DSM-IV EDNOS and increased cases of specified eating disorders. © 2016 Wiley Periodicals, Inc.(Int J Eat Disord 2017; 50:578-581)