232 research outputs found
Synthesis of Enantiopure Oxygen- and Nitrogen-Containing Heterocycles by Diastereoselective Ring-Closing Metathesis Reaction in Perhydro-1,3-benzoxazine Derivatives
Producción CientíficaDiastereoselective ring‐closing metathesis reactions on chiral trienic perhydro‐1,3‐benzoxazines derived from (−)‐8‐aminomenthol featuring two diastereotopic olefin chains is described. The diastereochemical outcome of the cyclization appeared to be dependent on the length and position of the olefin chains in perhydro‐1,3‐benzoxazine, the degree of substitution of the double bonds and the ruthenium catalyst used. After separation of the diastereomers, and removal of the chiral auxiliary, enantiopure oxygen‐ and nitrogen‐containing heterocycles were obtained.Ministerio de Economía, Industria y Competitividad (Project FEDER-CTQ2014-59870-P)Junta de Castilla y León (Ref. Project FEDER-VA115P17
Humanistic creative education university student: specificity in the learning of Physics
El presente artículo muestra algunos de los resultados a la luz del Proyecto: “Formación de
Profesores en Creatividad Aplicada”, financiado por el Programa de Cooperación
Interuniversitaria e Investigación Científica (PCI-AECID, 2009-10). Su intención fundamental consiste
en la aportación teórica-práctica del tratamiento a este tema, a través del proceso de enseñanza
aprendizaje de la Física, en base a un estudio realizado en la facultad de Físico-matemáticas de la
Universidad Autónoma de Nuevo León. Se parte de que en diferentes fuentes se encuentran
interesantes propuestas relacionadas con el desarrollo de la creatividad, pero en su mayoría la
abordan desde la dimensión cognitiva. Se exponen las bases teóricas fundamentales en las que se
sustenta el estudio. Se aplican diferentes técnicas (encuestas a estudiantes y docentes, variante
de técnica de Guilfort, composiciones) para comprobar el estado del objeto de investigación y a
partir de los resultados obtenidos, se presentan posibles vías de solución.This article demonstrates some results related to the Project: “Teacher Training in Applied Creativity”
(Interuniversity Cooperation Programme and Scientific Research) (PCI-AECID, 2009-10). Its
fundamental aim is the theoretical and practical contribution of treatment to this issue through the
process of teaching and learning of physics, based on a study in the power physics and
mathematics at the Autonomous University of Nuevo León. It assumes that different sources are
interesting proposals concerning the development of creativity, but most of the address from the
cognitive dimension. Presents the fundamental theoretical bases that underpin the study. Apply
different techniques to check the status of the research object and from the results, are possible
solutions
La Informática como materia fundamental en un sistema educativo del siglo XXI
Es innegable la importancia que ha alcanzado la
informática en la sociedad, y ya es imprescindible
para entender y tener éxito en el mundo actual. Sin
embargo, en el currículo educativo de primaria y
secundaria esta importancia no se ve reflejada, y la
informática aparece como asignatura complementaria
orientada a usuarios. Creemos que ha llegado el
momento de que, al igual que en otros países avanzados,
la informática dé el paso a materia troncal. Con
la reciente reforma de la LOMCE se ha perdido una
buena oportunidad para esto. Sin embargo, esto puede
paliarse mediante la definición de una asignatura con
estructura y contenidos concretos orientada al pensamiento
computacional y a la formación de creadores.SUMMARY -- The importance of computing in our society is undeniable.
It is essential to understand and be successful
in the current world. However, the educational curricula
for primary and secondary school does not
reflect this, and computing appears just as a useroriented,
complementary subject. We believe that the
time has come for computing to be a core area, as it is
in other advanced countries. The recent reformation
of the education law in Spain (LOMCE) was a missed
opportunity to achieve this. Nevertheless, it can be
somehow remedied by defining a subject with a
structure and concrete contents, oriented towards the
computational thinking and the developing of creators
Key-recovery attacks on KIDS, a keyed anomaly detection system
Most anomaly detection systems rely on machine learning algorithms to derive a model of normality that is later used to detect suspicious events. Some works conducted over the last years have pointed out that such algorithms are generally susceptible to deception, notably in the form of attacks carefully constructed to evade detection. Various learning schemes have been proposed to overcome this weakness. One such system is Keyed IDS (KIDS), introduced at DIMVA "10. KIDS" core idea is akin to the functioning of some cryptographic primitives, namely to introduce a secret element (the key) into the scheme so that some operations are infeasible without knowing it. In KIDS the learned model and the computation of the anomaly score are both key-dependent, a fact which presumably prevents an attacker from creating evasion attacks. In this work we show that recovering the key is extremely simple provided that the attacker can interact with KIDS and get feedback about probing requests. We present realistic attacks for two different adversarial settings and show that recovering the key requires only a small amount of queries, which indicates that KIDS does not meet the claimed security properties. We finally revisit KIDS' central idea and provide heuristic arguments about its suitability and limitations
Adsorption of bentazon on CAT and CARBOPAL activated carbon: experimental and computational study
Removal of the bentazon by adsorption on two different types of activated carbon was investigated under various experimental conditions.Kinetics of adsorption is followed and the adsorption isotherms of the pesticide are determined. The effects of the changes in pH, ionic strength and temperature are analyzed. Computational simulation was employed to analyze the geometry and the energy of pesticide absorption on activated carbon. Concentration of bentazon decreases while increase all the variables, from the same initial concentration. Experimental data for equilibrium was analyzed by three models: Langmuir, Freundlich and Guggenheim–Anderson–de Boer isotherms. Pseudo-first and pseudo-second-order kinetics are tested with the experimental data, and pseudo-second-order kinetics was the best for the adsorption of bentazon by CAT and CARBOPAL with coefficients of correlation R 2 = 0.9996 and R 2 = 0.9993, respectively. The results indicated that both CAT and CARBOPAL are very effective for the adsorption of bentazon from aqueous solutions, but CAT carbon has the greater capacity.Laboratorio de Estudio de Compuestos Orgánico
Morfometria de copa en Prosopis alba Griseb.
The morphometric relations allow describing and characterizing the dimensions of trees, stands without prior knowledge of the age and have utility in silvicultural management, forest monitoring and productivity, especially when there is a premise of making a sustainable use of forests. The objectives of the present study were to determine the morphometric indices according to their social positions (PS), correlate them, and create predictive models of these indices, because the dimensions and architecture of the crown may vary according to the PS. The data collection was carried out in three provinces of the Chaqueña Region, Argentina. In 100 individuals with DBH> 15 cm were measured: total height (Ht), diameter at breast height (DAP), crown length (Hc), crown radius (Rc), through which it was calculated the crown diameter (Dc), crown volume (Vc), slenderness rate (E), range index (Ia), crown section (Gc), salience index (IS), crown percentage (%c) and crown formal (Fc). The variables were subjected to the Pearson correlation analysis. The results indicate that there are positive correlations between % C, Ht, Hc, Dc and DAP, while E and Is showed negative correlations with DAP. The morphometric relationships of Prosopis alba can be accurately estimated using regression models. The results indicate that morphometric features can be described using a unique model, with the use of dummy classification variables that differentiate the sociological positions in individuals of Prosopis alba.Las relaciones morfométricas permiten describir y caracterizar las dimensiones de los árboles, rodales sin el conocimiento previo de la edad, tienen utilidad en el manejo silvicultural, monitoreos forestales y productividad, especialmente cuando se tiene como premisa hacer un uso sustentable de los bosques. Los objetivos del presente trabajo fueron determinar índices morfométricos según su posición social (PS), correlacionarlos, y crear modelos de predicción de esos índices, ya que las dimensiones y arquitectura de la copa pueden variar en virtud PS. La recolección de datos se realizó en tres provincias de la Región Chaqueña, Argentina. En 100 individuos con DAP> 15 cm, se midieron: altura total (Ht), diámetro a la altura del pecho (DAP), longitud de copa (Hc), radios copa (Rc), a través de los cuales se calcularon: diámetro de copa (Dc), volumen de copa (Vc), grado de esbeltez (E), índice de amplitud (Ia), sección de copa (Gc), índice saliente (Is), porcentaje de copa (%C) y forma de copa (Fc). Las variables fueron sometidas al análisis de correlación de Pearson. Los resultados indican que existen correlaciones positivas entre %C, Ht, Hc, Dc y el DAP, mientras que E e Is mostraron correlaciones negativas con el DAP. Las relaciones morfométricas de Prosopis alba pueden estimarse con precisión mediante modelos de regresión. Los resultados apuntan que los rasgos morfométricos pueden ser descriptos mediante un modelo único, con la utilización de variables de clasificación dummy que diferencian las posiciones sociológicas en individuos de Prosopis alba
Adsorption of bentazon on CAT and CARBOPAL activated carbon: experimental and computational study
Removal of the bentazon by adsorption on two different types of activated carbon was investigated under various experimental conditions.Kinetics of adsorption is followed and the adsorption isotherms of the pesticide are determined. The effects of the changes in pH, ionic strength and temperature are analyzed. Computational simulation was employed to analyze the geometry and the energy of pesticide absorption on activated carbon. Concentration of bentazon decreases while increase all the variables, from the same initial concentration. Experimental data for equilibrium was analyzed by three models: Langmuir, Freundlich and Guggenheim–Anderson–de Boer isotherms. Pseudo-first and pseudo-second-order kinetics are tested with the experimental data, and pseudo-second-order kinetics was the best for the adsorption of bentazon by CAT and CARBOPAL with coefficients of correlation R 2 = 0.9996 and R 2 = 0.9993, respectively. The results indicated that both CAT and CARBOPAL are very effective for the adsorption of bentazon from aqueous solutions, but CAT carbon has the greater capacity.Laboratorio de Estudio de Compuestos Orgánico
La discapacidad en el ámbito tributario español.
El presente trabajo proyectará un estudio exhaustivo y sintetizado de la figura del discapacitado en España, así como las relaciones de este y su entorno con la Administración Tributaria. Con ello, se reflejará y analizará la normativa específica aplicable a este colectivo a través de las principales figuras impositivas de naturaleza variada que promueven una discriminación positiva con el objetivo de asegurar el principio de igualdad efectiva, un Derecho Fundamental plasmado en el artículo 14 de la Constitución Española, norma suprema de nuestro Ordenamiento Jurídico.<br /
How to Reduce the Laparoscopic Colorectal Learning Curve
Producción CientíficaThe laparoscopic approach for colorectal pathologies is becoming more widely used, and surgeons have had to learn how to perform this new technique. The purpose of this work is to study the indicators of the learning curve for laparoscopic colectomy in a community hospital and to find when the group begins to improv
Inventario de Problemas Interpersonales-32 (IIP-32): Propiedades psicométricas y datos normativos en una muestra clínica de Argentina
This study analyzes the psychometric properties of the Inventory of Interpersonal Problems-32 (IIP-32), the most widely used instrument to measure relational difficulties. A sample of 2128 participants completed the IIP-32 and two additional measures of interpersonal difficulties before starting a psychotherapy treatment. To evaluate reliability, we analyzed internal consistency and item homogeneity. We analyzed the construct validity of IIP-32 through a confirmatory factor analysis and the concurrent validity through correlations between the IIP-32 and other measures of interpersonal deficits. The results of the study show excellent internal consistency and homogeneity of the items in the IIP-32. Furthermore, the results show construct validity as well as concurrent validity of the instrument. In sum, the results of this paper rank the IIP-32 as a reliable and valid instrument with important clinical implications to measure interpersonal difficulties in Argentina.Este estudio analiza las propiedades psicométricas del Inventario de Problemas Interpersonales-32 (IIP-32), la medida más utilizada para evaluar dificultades en las relaciones interpersonales. Una muestra de 2128 participantes completaron el IIP-32 y otras medidas de dificultades interpersonales antes de comenzar un tratamiento psicoterapéutico. Para evaluar la confiabilidad se analizaron medidas de consistencia interna y de homogeneidad de ítems. Se analizó la validez del constructo mediante un análisis factorial confirmatorio y la validez concurrente mediante correlaciones entre el IIP-32 y otras medidas de problemáticas interpersonales. Los resultados muestran excelentes niveles de consistencia interna y homogeneidad de ítems. A su vez, los resultados muestran la validez de constructo y validez de concurrente del instrumento. En síntesis, los resultados del trabajo posicionan al IIP-32 como un instrumento de confiabilidad y validez para estudiar dificultades interpersonales con importantes implicancias para la práctica clínica en Argentina
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