Mexica Music

This paper explores the society of Mexica, or the Aztecs, and some of the instruments that were produced in the civilization and used in today’s compositions. The history and their creation mythology will also be deliberated for those individuals who do not know this information of the culture. In the history, the subjects of the Mexica constructing a giant city in a lake to the conquest that was lead by Hernan Cortez will be discussed. The creation story will also exhibit the ideology of the Mexica and how their culture is sustained before the conquest. In the music section, the percussion and wind instruments are listed and described what they are used for in a music piece or other cultural usage. Some of these instruments are also illustrated on how they were created and how musicians play them today. The following will also be describing the importance of these instruments when they are performed in a Mexica ceremonial music piece

On the use of machine learning algorithms in the measurement of stellar magnetic fields

Regression methods based in Machine Learning Algorithms (MLA) have become an important tool for data analysis in many different disciplines. In this work, we use MLA in an astrophysical context; our goal is to measure the mean longitudinal magnetic field in stars (H_ eff) from polarized spectra of high resolution, through the inversion of the so-called multi-line profiles. Using synthetic data, we tested the performance of our technique considering different noise levels: In an ideal scenario of noise-free multi-line profiles, the inversion results are excellent; however, the accuracy of the inversions diminish considerably when noise is taken into account. In consequence, we propose a data pre-process in order to reduce the noise impact, which consists in a denoising profile process combined with an iterative inversion methodology. Applying this data pre-process, we have found a considerable improvement of the inversions results, allowing to estimate the errors associated to the measurements of stellar magnetic fields at different noise levels. We have successfully applied our data analysis technique to two different stars, attaining by first time the measurement of H_eff from multi-line profiles beyond the condition of line autosimilarity assumed by other techniques.Comment: Accepted for publication in A&

Level of Automation and Failure Frequency Effects on Simulated Lunar Lander Performance

A human-in-the-loop experiment was conducted at the NASA Ames Research Center Vertical Motion Simulator, where instrument-rated pilots completed a simulated terminal descent phase of a lunar landing. Ten pilots participated in a 2 x 2 mixed design experiment, with level of automation as the within-subjects factor and failure frequency as the between subjects factor. The two evaluated levels of automation were high (fully automated landing) and low (manual controlled landing). During test trials, participants were exposed to either a high number of failures (75% failure frequency) or low number of failures (25% failure frequency). In order to investigate the pilots' sensitivity to changes in levels of automation and failure frequency, the dependent measure selected for this experiment was accuracy of failure diagnosis, from which D Prime and Decision Criterion were derived. For each of the dependent measures, no significant difference was found for level of automation and no significant interaction was detected between level of automation and failure frequency. A significant effect was identified for failure frequency suggesting failure frequency has a significant effect on pilots' sensitivity to failure detection and diagnosis. Participants were more likely to correctly identify and diagnose failures if they experienced the higher levels of failures, regardless of level of automatio

Sensing parameters as a function of the chemical structure and thickness of two poly(styrene)-type based composites with carbon black

Sensing parameters of polymer composite layers were studied as a function of the polymer matrix structure and the initial resistance of the composite layers. Composites of Poly(styrene) and 4-Chloro-poly(styrene) at the same volume fraction of carbon black (8.7% V/V) were prepared by ultrasonic dispersion. Composite layers with different thicknesses and resistances were deposited by spin coating technique on flexible substrates from commercial cellulose acetate foils. Both kind of composite layers with initial resistances of 10, 50 and 100 kΩ were exposed to Acetone, Tetrahydrofuran, Chloroform and Toluene. Results evidenced that selectivity is very dependent on the chemical structure of the polymer matrix and sensitivity to the initial film electrical resistance. PS-based composite series were selective to Tetrahydrofuran whereas that 4ClPS-based composite series were selective to Acetone as expected due to their solubility parameters. For both composite series sensitivity increased for layers with less than 100 kΩ resistances. For all tested solvents 4ClPS-based composites showed higher sensitivities than PS-based composites. The response times for both series were into the range of 2 to 150 s and recovery times were in the range of 30 to 2000 s.SIEA-UAEM, 1025/2014RIF

Optimization of System Maturity and Equivalent System Mass for Exploration Systems Development Planning

The Exploration Systems Mission Directorate of the National Aeronautics and Space Administration (NASA) is currently pursuing the development of the next generation of human spacecraft and exploration systems throughout the Constellation Program. This includes, among others, habitation technologies for supporting lunar and Mars exploration. The key to these systems is the Exploration Life Support (ELS) system that composes several technology development projects related to atmosphere revitalization, water recovery, waste management and habitation. The proper functioning of these technologies is meant to produce sufficient and balanced resources of water, air, and food to maintain a safe and comfortable environment for long-term human habitation and exploration of space

Gestión directiva en la práctica docente de una Institución educativa, Yarinacocha - Ucayali, 2021

El objetivo general de la investigación fue determinar la influencia de la gestión directiva en la práctica docente de una Institución educativa, Yarinacocha - Ucayali, 2021 . La población estuvo conformada por docentes y jerárquicos quienes formaron parte de la investigación, a su vez la muestra estuvo compuesta por 67 docentes. El método empleado fue el hipotético-deductivo, el diseño no experimental y correlacional causal. Se desarrolló la técnica de la encuesta, y el instrumento fue un cuestionario diseñado en Google formularios que se utilizó para recoger información de los docentes. Para la confiabilidad del instrumento se utilizó el alfa de Cronbach para la Gestión directiva de 0,976 y para la variable Práctica docente fue de 0,977. Los resultados del análisis descriptivo de la gestión directiva arrojaron bueno en un 55.2%, mientras que, en la práctica docente, bueno 56.7%. De acuerdo al estadístico regresión ordinal (R2), se concluyó que la gestión directiva influye en la práctica docente de una Institución educativa, Yarinacocha - Ucayali, 2021 . (Nagelkerke= 0,485). Esto confirmó la hipótesis y el objetivo general del estudio

Desafíos de la gestión comunitaria del turismo en las cascadas de micos, San Luis Potosí (México)

El aprovechamiento turístico de paisajes atractivos compuestos por cuerpos de agua, bosques, selvas, grutas, montañas y por la diversidad biológica, ha venido incrementándose en las últimas décadas, y esto no ha sido sólo impulsado por el incremento de turistas extranjeros y nacionales en México que buscan la apreciación de la naturaleza, sino también por la crisis de la economía rural que ha venido agudizándose desde que el modelo económico neoliberal adoptado en México desde los años ochenta, lo que se ha reflejado en una drástica baja en los apoyos gubernamentales y en los subsidios al campo. Es así como el turismo de naturaleza en sus diversas modalidades se ha convertido en una alternativa económica más para las poblaciones campesinas en la búsqueda de lograr mejores niveles de vida.Este estudio tiene como objetivo analizar la gestión rural colectiva en torno al aprovechamiento turístico de las Cascadas de Micos de la Huasteca Potosina (México). Para ello se analiza la incidencia de la actividad sobre los bienes naturales, la gobernanza interna, el capital social, la economía local, así como la interacción con las presiones y las oportunidades del entorno político-económico. Se identifican tanto los factores que han facilitado el proceso de aprovechamiento turístico, así como los desafíos determinantes para la continuidad y mejoramiento de la gestión colectiva de los bienes naturales.Universidad Autónoma del Estado de México- CONACY

Mandibulectomia para exérese de Schwannoma: caso clínico.

The malignant tumor of the peripheral nerve sheath (TMVNP) is a rare mesenchymal tumor that arises from the cells of the peripheral nerve sheath. Has an aggressive behavior. It usually occurs in the extremities and in the trunk, being very rare in the head and neck. We report a rare case of TMVNP of the lower dental nerve in it mandibular intraosseous path, not associated with neurofibromatosis.O tumor maligno da bainha do nervo periférico (TMVNP) é um tumor mesenquimal raro que surge das células da bainha do nervo periférico. Tem um comportamento agressivo. Geralmente ocorre nas extremidades e no tronco, sendo muito rara sua presença na cabeça e pescoço. Relatamos um caso raro de TMVNP do nervo dentário inferior em seu trajeto intraósseo mandibular, não associado a neurofibromatose

Intracellular trafficking and cellular uptake mechanism of PHBV nanoparticles for targeted delivery in epithelial cell lines

Indexación: Web of Science; Scopus; Scielo.Background: Nanotechnology is a science that involves imaging, measurement, modeling and a manipulation of matter at the nanometric scale. One application of this technology is drug delivery systems based on nanoparticles obtained from natural or synthetic sources. An example of these systems is synthetized from poly(3-hydroxybutyrate-co-3-hydroxyvalerate), which is a biodegradable, biocompatible and a low production cost polymer. The aim of this work was to investigate the uptake mechanism of PHBV nanoparticles in two different epithelial cell lines (HeLa and SKOV-3). Results: As a first step, we characterized size, shape and surface charge of nanoparticles using dynamic light scattering and transmission electron microscopy. Intracellular incorporation was evaluated through flow cytometry and fluorescence microscopy using intracellular markers. We concluded that cellular uptake mechanism is carried out in a time, concentration and energy dependent way. Our results showed that nanoparticle uptake displays a cell-specific pattern, since we have observed different colocalization in two different cell lines. In HeLa (Cervical cancer cells) this process may occur via classical endocytosis pathway and some internalization via caveolin-dependent was also observed, whereas in SKOV-3 (Ovarian cancer cells) these patterns were not observed. Rearrangement of actin filaments showed differential nanoparticle internalization patterns for HeLa and SKOV-3. Additionally, final fate of nanoparticles was also determined, showing that in both cell lines, nanoparticles ended up in lysosomes but at different times, where they are finally degraded, thereby releasing their contents. Conclusions: Our results, provide novel insight about PHBV nanoparticles internalization suggesting that for develop a proper drug delivery system is critical understand the uptake mechanism.https://jnanobiotechnology.biomedcentral.com/articles/10.1186/s12951-016-0241-