An Extension to the Best Numerical Integration Formula Development

A mathematical analysis seeking an accurate measure of the worth of numerical integration techniques used for real-time digital flight simulation problems is presented. This investigation allows the subject of best integration methods to be pursued making emphasis on the choice of practical steps and the use of available mathematical techniques to illustrate and evaluate a potential root matching approach involving a selected first-order differential system. This study allows certain evaluation techniques to be developed. Notable among these are the schemes for comparing roots of sampled ideal integrators to roots of sampled approximated integrators, the development of an integration and of an iteration formula, and the creation of a computer program

Risk aversion and debt maturity structure

We study the relationship of risk aversion and debt maturity structure. In a model in which adverse selection in financial markets creates a role for the use of short-term debt, we allow the possibility of borrowers being risk-averse. This creates a trade-off between reduced expected financing costs and higher risk and allows for the study of the effect of risk aversion on optimal maturity structure. We prove that, as risk aversion increases, so does the percentage of debt that is long-term.risk aversion, debt maturity structure, adverse selection.

Assessing the Link between Adolescent Fertility and Urban Crime

We use data of neighborhoods of Bogotá to assess the causal relation between their adolescent fertility and their homicide rates. We find that neighborhoods with high adolescent fertility rates, and that have low secondary enrollment and high crime rates at the moment the children of their teen mothers become teenagers, are more likely to have higher homicide rates in the future, when those children reach their peak crime ages, estimated to be between 18 to 26 years old in violent cities of Colombia. The result is robust to various specifications, and to modeling the spatial autocorrelation of homicides.Crime, Illegal Behavior, Law Enforcement, Adolescent Fertility, Spatial Econometrics. Classification JEL: K40, K42, R21, J13, C21

Neural, cellular and molecular mechanisms of active forgetting

The neurobiology of memory formation attracts much attention in the last five decades. Conversely, the rules that govern and the mechanisms underlying forgetting are less understood. In addition to retroactive interference, retrieval-induced forgetting and passive decay of time, it has been recently demonstrated that the nervous system has a diversity of active and inherent processes involved in forgetting. In Drosophila, some operate mainly at an early stage of memory formation and involves dopamine (DA) neurons, specific postsynaptic DA receptor subtypes, Rac1 activation and induces rapid active forgetting. In mammals, others regulate forgetting and persistence of seemingly consolidated memories and implicate the activity of DA receptor subtypes and AMPA receptors in the hippocampus (HP) and related structures to activate parallel signaling pathways controlling active time-dependent forgetting. Most of them may involve plastic changes in synaptic and extrasynaptic receptors including specific removal of GluA2 AMPA receptors. Forgetting at longer timescales might also include changes in adult neurogenesis in the dentate gyrus (DG) of the HP. Therefore, based on relevance or value considerations neuronal circuits may regulate in a time-dependent manner what is formed, stored, and maintained and what is forgotten.Fil: Medina, Jorge Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentin