An empirical way to correct some drawbacks of mulliken population analysis

Indexación: ScieloThe problem of negative electronic populations and of occupation numbers greater than 2 has plagued Mulliken Population Analysis since the very beginning. Through the analysis of three model molecular systems, several basis sets and the relevant literature, we conclude that there is not enough evidence to assign the origin of these errors to the self-consistent scheme, to Mulliken's partition, to the basis set structure or to a combination of these. As Mulliken Population Analysis is still widely used, we have developed an empirical method to eliminate negative electronic populations and occupation numbers greater than 2. This method can be used for any partition of the electron density (not only Mulliken's), for any basis set and for any LCAO-MO methodology (semiempirical or ab initio). Finally, the method does not produce any change in the original atomic net charges.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072009000400036&lng=es&nrm=is

An approximate dynamic programming approach to risk sensitive control of execution costs

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 43-44).We study the problem of optimal execution within a dynamic programming framework. Given an exponential objective function, system variables which are normally distributed, and linear market dynamics, we derive a closed form solution for optimal trading trajectories. We show that a trader lacking private information has trajectories which are static in nature, whilst a trader with private information requires real time observations to execute optimally. We further show that Bellman's equations become increasingly complex to solve if either the market dynamics are nonlinear, or if additional constraints are added to the problem. As such, we propose an approximate dynamic program using linear programming which achieves near-optimality. The algorithm approximates the exponential objective function within a class of linear architectures, and takes advantage of a probabilistic constraint sampling scheme in order to terminate. The performance of the algorithm relies on the quality of the approximation, and as such we propose a set of heuristics for its efficient implementation.by David Jeria.M.Eng

A theoretical structure-affinity relationship study of some cannabinoid derivatives

Indexación: ScieloA ZINDO/1 quantum-chemical structure-affinity relationship study with the KPG model is presented for the in vitro interaction of a group of classical, indole-derived and aminoalkylindole-derived cannabinoids with CB and CB2 receptors. From this work the following conclusions are obtained. CB and CB2 CB2 receptor affinities are regulated by different mechanisms involving orbital and charge control. Nevertheless CB and CB2 classical ligands share three common features: a hydrogen bond to a lysine (for CB ) or serine (for CB), a fully aromatic ring and a branched carbon side chain. In the case of indole-derived and aminoalkylindole-derived cannabinoids orientation and alignment rules have been defined as a basis for the comparison of noncongeneric molecules. In this way it was possible to associate the location of molecular fragments of these systems with known molecular systems such as classical cannabinoids. For aminoalkyhndoles we have proposed the locus with which they bind to a second receptor site that is available to WIN-55212-2 but not to classical cannabinoids. On the basis of our results we propose a new molecule that should help to discriminate between the above two receptor sites.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072008000100013&nrm=is

[Chile] National Cybersecurity Policy (2017-2022)

Identifies public policy measures for 2017-2018, and identifies the national standards and institutions involved in cybersecurity, Provides a risk and threat overview; Identifies the following policy objectives to reach by 2022: Robust and resilient information infrastructure, prepared to face and recover from cybersecurity incidents, under a risk management approach; Protection of people’s rights in cyberspace; Development of a cybersecurity culture based on education, good practices and accountability in the management of digital technologies; Cooperation actions with other stakeholders in the field of cybersecurity and active participation in international forums and discussions; Promoting the development of a cybersecurity industry serving its strategic objectives

¿Cómo leemos un texto hipertextual?: una exploración de la lectura de literatura digital

Indexación: Revista UNAB.La literatura digital es un tipo de escritura concebida para ser leída en la pantalla de un dispositivo electrónico. Esto conlleva no solo una amplitud en las posibilidades de la creación, sino que también analizar la práctica de su lectura puede permitirnos identificar características vinculadas a la lectura en digital. Para estudiar este fenómeno, 45 estudiantes de primer año de literatura desarrollaron una bitácora de experiencia lectora. Los participantes plasmaron su experiencia lectora antes, durante y después de Pentagonal: incluidos tú y yo del escritor Carlos Labbé. Pudimos identificar cuatro categorías fundamentales: la hipertextualidad, la materialidad, el género y el rol del lector. Este estudio nos permitió verificar las fortalezas y debilidades de la bitácora y establecer hipótesis para futuras investigaciones sobre la lectura en digital.The aim of this paper is to identify characteristics of reading in the digital medium. We choose digital literature as a place where we can explore this reading experience, because we consider that its reading can be compared to the practice of reading in other digital spaces. To study this phenomenon, we developed an instrument called reading experience log that was filled out by 45 freshman literature students. The participants portrayed their reading experiences before, during and after reading the hypernovel Pentagonal: incluidos tú y yo by Chilean writer Carlos Labbé. As a result, we identified four key categories to understand this reading practice: hypertextuality, materiality, genre and the role of the reader. This study allowed us to verify the strengths and weaknesses of the instrument and to establish hypotheses about digital reading that can be explored in future research in the area.http://revistahumanidades.unab.cl//wp-content/uploads/2017/06/C%C3%B3mo-leemos-un-texto-hipertextual.pd

Revisiting Career Path Assumptions: The Case of Woment in the IT Workforce

Many researchers have argued that additional systematic analysis of the information technology (IT) workforce is necessary in order to more deeply understand organizational human behavior as it relates to career anchors or values and motivations that attract an individual to a particular career. For these reasons the purpose of this paper is to examine the career anchors of women in the American IT workforce and their relationships to occupational decisions. The data for this examination comes from interpretive interviews conducted with 92 women and a quantitative survey conducted with an additional 210 women. The results of our analyses give cause for challenging some longstanding assumptions about career anchors that exist in the literature. This research also makes a theoretical contribution through its extension of an emergent theory about within-gender variation to the context of career anchor variations among women in the IT field

Memorias aparecidas en el aula del Museo Etnográfico

En el marco del 33 aniversario del golpe cívico militar que dio inicio a la última dictadura en nuestro país, el Museo Etnográfico “Juan B. Ambrosetti” de la Facultad de Filosofía y Letras de la UBA organizó la Semana de la Memoria que tuvo lugar entre los días 21 y 28 de marzo de 2009 en su sede. El Museo se comprometió con la historia reciente de la Facultad de Filosofía y Letras, y realizó un homenaje a los estudiantes, graduados y docentes de la Carrera de Antropología detenidosdesaparecidos y asesinados entre 1974 y 1983. Mostrar y difundir quiénes eran, brindar un espacio de conmemoración a sus familias y sus compañeros, y a todos los integrantes de la comunidad universitaria, fueron los aportes que realizamos para la reconstrucción de la memoria, en conjunto con el proyecto “Construyendo memorias”.Eje 4: Patrimonio UniversitarioRed de Museos de la Universidad Nacional de La Plat