Ecological-transaction model approach of adolescents’ parental maltreatment and peer-bullying: the moderating role of bullying at the classroom

INTRODUCTION: The present study examined the ecological-transactional model delineated by Cicchetti and Lynch (1993) and the nature of the association between adolescents’ parental maltreatment and victimization and bullying at school. METHOD: Multivariate multilevel regression analyses were conducted on a sample of 2.852 adolescents between the ages of 12 and 17 from 25 secondary schools. Data was nested across 133 classrooms. Classrooms level variables and individual variables in relationship to parental maltreatment, behavioural disorders, sex, and bullying and victimization were included in the analysis. RESULTS: Results indicated that adolescents who reported suffering violence at home, showed more vulnerability to becoming victims of bullying at school, with the relationship being moderated by the level of bullying in the classroom. It was also examined the role of behavioural disorders and a relation between these factors was found amongst the bullies but not the victims. DISCUSSION AND CONCLUSION: This study uses the systemic perspective of ecological-transactional model on child maltreatment to show the importance between the school and home microsystems in the perpetuation of victimization. The results imply that what children experience at home might cause emotional and behavioural differences in varying classroom climates at school. Therefore, understanding the interactions between systems’ transaction of socialisation mechanisms might contribute for effective anti-bullying programs

Online suboptimal control of linearized models

A novel approach to approximately solving the restricted-control LQR problem online is substantiated and applied in two case-studies.  The first example is a one-dimensional system whose exact solution is known.  The other one refers to the temperature control of a metallic strip at the exit of a multi-stand rolling mill.  The new (online-feedback) strategy employs a convenient version of the gradient method, where partial derivatives of the cost are taken with respect to the final penalization matrix coefficients and to the switching times where the control (de)saturates.  The calculations are based on exact algebraic formula, which do not involve trajectory simulations, and so reducing in principle the computational effort associated with receding horizon or nonlinear programming methods.   Fil: Costanza, Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); ArgentinaFil: Rivadeneira Paz, Pablo Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); Argentin

Approximating the Solution to LQR Problems with Bounded Controls

New equations involving the unknown final states and initial costates corresponding to families of LQR problems are shown to be useful in calculating optimal strategies when bounded control restrictions are present, and in approximating the solution to fixed-end problems. The missing boundary values of the Hamiltonian equations are obtained by (off-line) solving two uncoupled, first-order, linear partial differential equations for two auxiliary n×n matrices, whose independent variables are the time-horizon duration T and the eigenvalues of the final-penalty matrix S. The solutions to these PDEs give information on the behavior of the whole (T,S)-family of control problems.  Illustrations of numerical results are provided and checked against analytical solutions of  ´the cheapest stop of a train´ problem.Fil: Costanza, Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); ArgentinaFil: Rivadeneira Paz, Pablo Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico Para la Industria Química (i); Argentin

A Pharmacokinetic Model for Multiple-Dose Dynamics and Long-Term Treatment Effectiveness

This paper presents a novel pharmacokinetic model that utilizes Time Scale Calculus to analyze the dynamics of blood concentration resulting from multi-dose treatments. The proposed model offers a closed-form solution, termed the "Generalized Bateman function", which characterizes the blood concentration dynamics of orally administered multiple dosage regimens. We also investigate the asymptotic properties of this function to describe the long-term dynamics associated with specific dosage plans. Notably, we establish the ubiquitous existence of effective dosage schedules, meaning that a medical practitioner can always formulate a prescription ensuring that a patient's long-term blood concentration levels remain within a desired range. Furthermore, our framework highlights how different metabolisms can significantly influence long-term blood concentration dynamics in response to the same dosage. Lastly, we employ anecdotal treatment responses to Efavirenz as an illustrative example, demonstrating how individuals with distinct biological characteristics may require different dosage regimens to maintain effective drug blood concentrations over an extended period.Comment: 39 pages, 8 figure