223 research outputs found
First report of Desmiphora hirticollis (Olivier) (Coleoptera: Cerambycidae) on Wigandia urens (Ruiz and Pavón) H.B.K. (Hydrophilaceae) in Mexico
Desmiphora hirticollis (Olivier) (Coleoptera: Cerambycidae) was found in Oaxaca, Mexico, feeding in the stems of Wigandia urens (Ruiz and Pavón) H.B.K. (Hydrophilaceae), a new host record. Information about damage in the plant stems and some observations of the insect’s biology are provided
Effects of cardiorespiratory exercise on cognition in older women exposed to air pollution
The aim was to analyze the effects of cardiorespiratory exercise and air pollution on cognition and cardiovascular markers in four groups of older women: the active/clean air group (AC), the active/polluted air group (AP), the sedentary/clean air group (SC), and the sedentary/polluted air group (SP). Active groups performed a training task based on progressive walking. Prior to and after the experiment, the following parameters were assessed: cognition, by Mini Mental State Examination (MMSE); maximum oxygen uptake (VO2max), estimated by the Six-Minute Walk Test (6mWT); heart
rate (HR); and oxygen saturation (SpO2). There were significant differences (p < 0.05) between the AC and the SP in all the MMSE dimensions except “Registration”, and in all the physiological variables (VO2max, SpO2, HR). Aerobic exercise may be a protective factor against the effects that pollution
have on cognition and on the mechanisms of oxygen transport
CompareML: A Novel Approach to Supporting Preliminary Data Analysis Decision Making
There are a large number of machine learning algorithms as well as a wide range of libraries and services that allow one to create predictive models. With machine learning and artificial intelligence playing a major role in dealing with engineering problems, practising engineers often come to the machine learning field so overwhelmed with the multitude of possibilities that they find themselves needing to address difficulties before actually starting on carrying out any work. Datasets have intrinsic properties that make it hard to select the algorithm that is best suited to some specific objective, and the ever-increasing number of providers together make this selection even harder. These were the reasons underlying the design of CompareML, an approach to supporting the evaluation and comparison of machine learning libraries and services without deep machine learning knowledge. CompareML makes it easy to compare the performance of different models by using well-known classification and regression algorithms already made available by some of the most widely used providers. It facilitates the practical application of methods and techniques of artificial intelligence that let a practising engineer decide whether they might be used to resolve hitherto intractable problems. Thus, researchers and engineering practitioners can uncover the potential of their datasets for the inference of new knowledge by selecting the most appropriate machine learning algorithm and determining the provider best suited to their data
Volatilidad en los precios de los cereales básicos y su impacto en la seguridad alimentaria. México, 1995-2018
Este documento analiza cómo la volatilidad en los precios de los granos básicos, arroz, maíz y trigo, influyen sobre la seguridad alimentaria. Para esto, se estudió el mercado de estos productos mediante los modelos de varianza condicional heterocedástica: simétricos y asimétricos. Entre los resultados, se encontró evidencia que, ante un escenario internacional volátil, los precios de granos básicos a nivel doméstico se elevarán, repercutiendo de manera negativa a toda la cadena de transformación mediante el incremento en los precios finales de los productos procesados. A nivel social, este escenario genera un efecto restricción sobre la población al reducir el acceso de los alimentos a menor precio
Revision of the New World Genus Crassomicrodus Ashmead (Hymenoptera, Braconidae, Agathidinae), with an Identification Key to Species
A key to species and descriptions are presented for 14 species of the New World genus Crassomicrodus Ashmead. Seven new species, Crassomicrodus azteca, Crassomicrodus clypealis, Crassomicrodus costaricensis, Crassomicrodus jalisciensis, Crassomicrodus mariae, Crassomicrodus oaxaquensis,and Crassomicrodus olgae are described. Crassomicrodus fenestratus (Viereck) is synonymized with Crassomicrodus nigriceps (Cresson). Crassomicrodus melanopleurus (Ashmead) is recognized as a valid species
Estructuras de datos y algoritmos
Estructuras de Datos y Algoritmos es una asignatura totalmente teórica complementada con la asignatura de Laboratorio de Programación II; se pretende que el alumno aprenda a manejar con soltura las estructuras de datos y estructuras de programación que se deben utilizar a la hora de desarrollar cualquier tipo de software, de manera eficiente y elegante; temiendo como base siempre la Programación Orientada a Objetos. Exponemos aquí una visión general de la asignatura con el temario impartido
Long-term influence of chitin concentration on the resistance of cement pastes determined by atomic force microscopy
The presence of sulfates potentialize damage on cementbased materials, leading to structural failures. Therefore, structures must be designed to compensate for this effect. The mechanical properties of cement–chitin mixtures are investigated with different percentages of chitin (0.5, 1.3, and 2.1 wt.%) and aging of composite in a joint nanoscopic- and macroscopic-scale by experimental study. The objective is to increase the durability of concrete elements at coastal aquifers where concrete structures are in constant exposure to sulfate ions, chloride ions among others. Tapping mode AFM was used to characterize the surface structure and roughness of the cement pastes. To verify the chitin addition and the formation of sulfate-based aggregates Raman and IR spectra were recorded and are presented in this work. Then, force spectroscopy was used to obtain the nanomechanical properties at three different
exposure times (1 day, 6 months, and 1 year) into water or a SO4 2 environment. Macroscopic parameters (e.g., compression strength of cylindrical probes) were assessed for comparison following standard guidelines. The results show a decrease of its mechanical properties as a function of the polymer concentration but more importantly, they correlate the elasticity and adhesion at the nanoscale with the behavior of the bulk material
Laboratorio de Programación II
La asignatura de Laboratorio de Programación II es complementaria de Laboratorio de Programación l; se pretende que el alumno alcance un grado mínimo en la programación de lenguajes orientados a objetos. Exponemos aquí una visión general de la asignatura con el temario y la problemática que encontramos en la didáctica de la misma
Diversidad de especies de Blacus (Hymenoptera: Braconidae, Blacinae) en dos ecosistemas forestales de Michoacán, México
Este estudio estimó la diversidad de avispas del género Blacus Nees (Braconidae, Blacinae) en dos ecosistemas forestales del noreste de Michoacán, en el Eje Neovolcánico Transversal: Parque Nacional Cerro de Garnica (PN C-Garnica) y Zona Protectora Forestal Los Azufres (ZPF Los Azufres). Se elaboró un mapa de cobertura vegetal con imágenes satelitales de estos ecosistemas forestales. La captura de especímenes se realizó mensualmente desde marzo 2008 hasta febrero 2010 con la ayuda de platos-trampa de color amarillo. Se capturó un total de 172 especímenes de 17 especies del género Blacus, de los cuales 84.3% provinieron del PN C-Garnica (13 especies) y 15.7% de la ZPF Los Azufres (10 especies). El porcentaje de similitud indicó una composición de especies diferente entre las dos áreas estudiadas (índice de Jaccard = 0.35). En el PN C-Garnica se capturaron significativamente más especímenes por mes que en la ZPF Los Azufres (12.1 ± 4.0 vs 2.3 ± 1.20). De acuerdo con el índice de Shannon-Wiener, la diversidad fue similar en ambas áreas estudiadas (2.1 vs 1.9). Los estimadores de riqueza Chao 2 y Jackknife 2 indicaron que en ambas áreas se capturó ~60% de las especies esperadas. Se concluye que el PN C-Garnica y la ZPF Los Azufres mantienen una alta diversidad de especies de Blacus. Las mayores abundancias, así como la mayor riqueza de especies se encontraron en el PN C-Garnica, la cual es una zona con mayor grado de perturbación.In this study, the diversity of wasps of the Blacus Nees (Braconidae, Blacinae) genus were estimated in two forest ecosystems in the northeastern part of Michoacán, in the Trans-Mexican Volcanic Belt: Cerro de Garnica National Park (C-Garnica NP) and Los Azufres Protected Forest Area (Los Azufres PFA). A vegetation cover map based on satellite images of these forest ecosystems was prepared. The specimens collecting was performed monthly from March 2008 until February 2010 with the help of yellow pan traps. A total of 172 specimens of 17 species of the genus Blacus were collected, of which 84.3% were from C-Garnica NP (13 species) and 15.7% from Los Azufres PFA (10 species). Percentage of similarity (Jaccard´s index = 0.35) was relatively low, indicating a different composition between both forest ecosystems. Significantly more specimens were monthly captured in C-Garnica NP than in Los Azufres PFA (12.1 ± 4.0 vs 2.3 ± 1.20). According to the Shannon-Wiener index, the diversity was similar in both studied areas (2.1 vs 1.9). Chao 2 and Jackknife 2 estimators indicated that ~60% of the expected species were captured in both areas. One concludes that C-Garnica NP and Los Azufres PFA maintain a high species diversity of Blacus. The greatest abundance, as well as the greatest species richness were found in the C-Garnica NP, which is an area with a higher degree of disturbance
SISTEMA DE MONITOREO PARA UN EQUIPO DE ESTUDIOS DE TIEMPOS Y MOVIMIENTOS
ResumenLos laboratorios de Ingeniería Industrial de la UAM-Azcapotzalco cuentan con equipos que sirven como apoyo para la enseñanza de asignaturas relacionadas con el estudio y mejoramiento de la productividad de procesos industriales. En este artículo se describe el diseño y construcción de un sistema que permite desplegar en una pantalla información asociada al desarrollo de experimentos relacionados con el estudio de tiempos y movimientos. El prototipo construido obtiene información del equipo encargado de controlar la secuencia de operación del sistema didáctico. A partir de estos datos se despliegan diversas pantallas que permiten a los operadores conocer información de las principales variables asociadas al ejercicio como son: modo de operación, tiempos de ciclo, tiempos por estación, número de piezas elaboradas, etc. El sistema basa su funcionamiento en una computadora embebida Raspberry, el intercambio de información entre ésta y el Controlador Lógico Programable del equipo didáctico se realiza mediante el protocolo Modbus. Pruebas realizadas han demostrado una operación correcta del prototipo, mismo que se empezará a utilizar en el siguiente período lectivo.Palabras Claves: Controladores Lógicos Programables, Modbus IP, Monitoreo de la Producción, Raspberry, Sistema Andon. MONITORING SYSTEM FOR AN EQUIPMENT OF STUDY OF TIMES AND MOVEMENTSAbstractThe Industrial Engineering Laboratories of the UAM-Azcapotzalco have equipment that serves as support for the teaching of subjects related to the study and improvement of the productivity of industrial processes. This article describes the construction of a system to display on screen, information associated with the development of experiments related to time and motion studies. This prototype obtains information from the controller in charge of the sequence of operation of the teaching system. Based on these data, several screens are displayed that allow operators to know information about the main variables associated with the exercise such as: operation mode, cycle time, time per work station, number of elaborated pieces, etc. The system bases its operation on a Raspberry embedded computer, the exchange of information between it and the Programmable Logic Controller of the teaching equipment is done through the Modbus protocol. Tests carried out have shown a correct operation of the prototype, which will begin to be used in the next school period.Keywords: Andon System, Modbus IP, Production Monitoring, Programmable Logic Controller, Raspberry
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