Remote Sensing for the Characterization of Covers and Meteorological Conditions of the Chimborazo Fauna Production Reserve

The objective of this research is to characterize the vegetation cover and meteorological conditions through a multispectral analysis of the Chimborazo Wildlife Production Reserve. The methodology used for this research is the one proposed by Chuvieco, which began with the definition of objectives, bibliographic review of the reserve’s canopy, download of the most appropriate satellite image (without cloud cover), definition of canopy categories, image correction, calculation of spectral indices, supervised classification, adjustments, map generation using GIS tools, and interpretation of the results. Additionally, a National Solar Radiation Database web platform was used to download meteorological data for the year 2020, which were used to characterize the study area; the results were compared with the data acquired in 2017 with a station installed in the reserve. In the end, it was determined that multispectral analysis allows generating data close to a field work study. For the faunal reserve, the following area of established covers were obtained: shrub vegetation 55.8 km2, snow 47.9 km2, eroded zone 125 km2, moor 190 km2, pasture 76 km2 and crops 30.56 km2. Average temperature 5∘C, relative humidity 95.8% and water precipitation 1.37. Keywords: Remote sensing, vegetation cover characterization, Chimborazo Wildlife Reserve, meteorological data, multispectral analysis, Vegetation Index. Resumen La presente investigación tiene como objetivo realizar una caracterización de las cubiertas vegetales y condiciones meteorológicas a través de un análisis multitespectral de la Reserva de Producción Faunística Chimborazo. La metodología que se utilizó para esta investigación es la propuesta por Chuvieco donde se empezó con la definición de objetivos, revisión bibliográfica de las cubiertas de la reserva, descarga de la imagen satelital más adecuada (sin nubosidad), definición de categorías de cubiertas, corrección de imágenes, cálculo de índices espectrales, clasificación supervisada, ajustes, generación de mapas mediante herramientas SIG e interpretación de los resultados. Adicionalmente se utilizó una plataforma web National Solar Radiation Database para la descarga de datos meteorológicos del año 2020 que sirvieron para realizar la caracterización de la zona de estudio, los resultados fueron comparados con los datos adquiridos del año 2017 con una estación instalada en la reserva. Al final se determinó que el análisis multiespectral permite generar datos cercanos a un estudio de trabajo en campo. Para la reserva faunística se obtuvo las siguientes área de las cubiertas establecidas: vegetación arbustiva 55.8 km2, nieve 47.9 km2, zona erosionada 125 km2, páramo 190 km2, pastos 76 km2 y cultivos 30.56 km2. La temperatura media 5∘C, humedad relativa 95.8 % y precipitación de agua 1.37. Palabras Clave: Sensoramiento Remoto, caracterización de cubiertas vegetales, Reserva Faunística Chimborazo, datos meteorológicos, análisis multiespectral, Indice de vegetació

Analysis of time-lapse data error in complex conductivity imaging to alleviate anthropogenic noise for site characterization

Previous studies have demonstrated the potential benefits of the complex conductivity (CC) imaging over electrical resistivity tomography for an improved delineation of hydrocarbonimpacted sites and accompanying biogeochemical processes. However, time-lapse CC field applications are still rare, in particular for measurements performed near anthropogenic structures such as buried pipes or tanks, which are typically present at contaminated sites. To fill this gap, we have developed CC imaging (CCI) results for monitoring data collected in Trecate (northwest Italy), a site impacted by a crude oil spill. Initial imaging results reveal only a poor correlation with seasonal variations of the groundwater table at the site (approximately 6 m). However, it is not clear to which extend such results are affected by anthropogenic structures present at the site. To address this, we performed a detailed analysis of the misfit between direct and reciprocal time-lapse differences. Based on this analysis, we were able to discriminate spatial and temporal sources of systematic errors, with the latter commonly affecting measurements collected near anthropogenic structures. Following our approach, CC images reveal that temporal changes in the electrical properties correlate well with seasonal fluctuations in the groundwater level for areas free of contaminants, whereas contaminated areas exhibit a constant response over time characterized by a relatively high electrical conductivity and a negligible polarization effect. In accordance with a recent mechanistic model, such a response can be explained by the presence of immiscible fluids (oil and air) forming a continuous film through the micro and macropores, hindering the development of ion-selective membranes and membrane polarization. Our results demonstrate the applicability of CCI for an improved characterization of hydrocarboncontaminated areas, even in areas affected by cultural noise

Corrosion study of pipeline carbon steel in sourbrine under turbulent flow conditions at 60°C

This work presents the electrochemical results obtained during the corrosion study of X52 pipeline steel sample, immersed in “sour” solution under turbulent flow conditions at 60°C. In order to obtain information on the corrosion kinetics, weight loss method, linear polarization resistance, impedance and polarization curves were used at different immersion times. In order to control the turbulent flow conditions, a rotating cylinder electrode was used at two different rotation rates, 0 and 1000 rpm. A surface analysis was carried out in order to identify the corrosion morphology and the corrosion product formed on the steel sample. In general, it was found that flow has a considerable influence upon the electrochemical process occurring on the surface of the steel. It was observed as the flow rate increased the corrosion rate also increased. In surface analysis three phases were found, mackinawite (Fe,Ni)  1+xS ,pyrrhothite (Fe(1-x)S) and marcasite (FeS2). In addition, a “localized attack” was found

Clinical and social profile of patients with pulmonary tuberculosis in Reynosa, Tamaulipas

Background: Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. It generally causes pulmonary tuberculosis, with symptoms such as fever and expectoration. In 2020, the total number of tuberculosis cases worldwide was about 9.8 million, with a mortality of 1.5 million. In Mexico, pulmonary tuberculosis represents 79% of the total cases of tuberculosis, with an incidence of 24 cases per 100,000 inhabitants. Tamaulipas ranks fifth nationally. This study seeks to determine the frequency in which social and risk factors associated with predisposition to tuberculosis occur in the population of Reynosa, Tamaulipas. Methods: Through an observational and descriptive study, data were collected from patients with active pulmonary tuberculosis belonging to the Regional Center Against Tuberculosis in Reynosa, Tamaulipas. Data collection was carried out from February to May 2022 through the clinical history of the unit. Those patients in fully cured condition and those who presented negative smear microscopy during this period were excluded. Results: In the February-May period, 50 records of patients with pulmonary tuberculosis were included, where 58% were men, with a mean age of 38.4 years ± 16.6 DE, 56% of the participants were from the state of Tamaulipas, followed by Veracruz and San Luis Potosí with 22% and 4% respectively. The predominant level of education was middle school (23.5%), followed by complete elementary school, while the occupation that prevailed was unemployed (41.2%) followed by housewife (21.6%). Among the frequent symptoms were productive cough (89.8%) and fever (65.3%). Of the comorbidities present, diabetes mellitus stood out with 26%, while in the addictions we found alcoholism (25.7%) in the first place. Conclusions: The importance of describing the social and clinical situation of patients with tuberculosis lies in the identification of risk factors that can be considered in the development of strategies focused on the clinical manifestations of our region

Bioactive Products From Plant-Endophytic Gram-Positive Bacteria

Endophytes constitute plant-colonizing microorganisms in a mutualistic symbiosis relationship. They are found in most ecosystems reducing plant crops’ biotic and abiotic stressors by stimulating immune responses, excluding plant pathogens by niche competition, and participating in antioxidant activities and phenylpropanoid metabolism, whose activation produces plant defense, structural support, and survival molecules. In fact, metabolomic studies have demonstrated that endophyte genes associated to specific metabolites are involved in plant growth promotion (PGP) by stimulating plant hormones production such as auxins and gibberellins or as plant protective agents against microbial pathogens, cancer, and insect pests, but eco-friendly and eco-safe. A number of metabolites of Gram-positive endophytes isolated from agriculture, forest, mangrove, and medicinal plants, mainly related to the Firmicutes phyla, possess distinctive biocontrol and plant growth-promoting activities. In general, Actinobacteria and Bacillus endophytes produce aromatic compounds, lipopeptides, plant hormones, polysaccharides, and several enzymes linked to phenylpropanoid metabolism, thus representing high potential for PGP and crop management strategies. Furthermore, Actinobacteria have been shown to produce metabolites with antimicrobial and antitumor activities, useful in agriculture, medicine, and veterinary areas. The great endophytes diversity, their metabolites production, and their adaptation to stress conditions make them a suitable and unlimited source of novel metabolites, whose application could reduce agrochemicals usage in food and drugs production

Optimal Nitrogen Fertilization to Reach the Maximum Grain and Stover Yields of Maize (Zea mays L.): Tendency Modeling

Utilization of maize stover to the production of meat and milk and saving the grains for human consumption would be one strategy for the optimal usage of resources. Variance and tendency analyses were applied to find the optimal nitrogen (N) fertilization dose (0, 100, 145, 190, 240, and 290 kg/ha) for forage (F), stover (S), cob (C), and grain (G) yields, as well as the optimal grain-to-forage, cob-to-forage, and cob-to-stover ratios (G:F, C:F, and C:S, respectively). The study was performed in central Mexico (20.691389° N and −101.259722° W, 1740 m a.m.s.l.; Cwa (Köppen), 699 mm annual precipitation; alluvial soils). N-190 and N-240 improved the individual yields and ratios the most. Linear and quadratic models for CDM, GDM, and G:F ratio had coefficients of determination (R2) of 0.20–0.46 (p < 0.03). Cubic showed R2 = 0.30–0.72 (p < 0.02), and the best models were for CDM, GDM, and the G:F, C:F, and C:S DM ratios (R2 = 0.60–0.72; p < 0.0002). Neither SHB nor SDM negatively correlated with CDM or GDM (r = 0.23–0.48; p < 0.0001). Excess of N had negative effects on forage, stover, cobs, and grains yields, but optimal N fertilization increased the proportion of the G:F, C:F, and C:S ratios, as well as the SHB and SDM yields, without negative effects on grain production

Expansión de la mancha urbana de la Ciudad de Chihuahua 2000-2012

En el presente trabajo se pretende dar a conocer el acelerado crecimiento de la mancha urbana de la ciudad de Chihuahua que se ha generado en tan solo diez años, mediante los Sistemas de Información Geográfica lo que hace una investigación novedosa e interesante, con estos sistemas podemos ver que, si bien la ciudad ha tenido un crecimiento en su espacio, económico y social no se  ha  dado  un  desarrollo  equilibrado  sobre  su  territorio.  Por  lo  que  el  objetivo  de  esta investigación es conocer las acciones políticas, sociales, ambientales y económicas, que produjeron la expansión de la mancha urbana en sus diferentes puntos cardinales de la Ciudad en los últimos 10 años, representados con los SIG. Generado problemáticas sobre todo en el tema de los asentamientos humanos en espacios carentes de características viables para una buena calidad de vida, dejando consecuencias en la estructura de la ciudad, tanto física como social, puesto que no se dio una adecuada planeación para el crecimiento de la mancha urbana

Distributed event-triggered communication for angular speed synchronization of networked BLDC motors

[EN] This work presents the design and implementation of a collaborative and decentralized control for synchronizing the angular velocity of a group of spatially distributed brushless direct current (BLDC) motors. Via an Active Disturbance Rejection Control (ADRC), acting as an internal-loop, the dynamics of the BLDC can be assimilated to that of a first-order integrator, which is considered an agent. Then, a decentralized collaborative control strategy with event-triggered communication is proposed, which solves the problem of leader-follower consensus for the multi-agent system and thus speed synchronization. The communication topology between agents is modeled using an undirected and connected graph. The decentralized control law incorporates an event function, which indicates the instant at which the i-th agent transmits the angular velocity information to its neighbor. An experimental platform using two BLDC and a virtual leader was developed to validate the proposed approach. The experimental results show excellent performance for angular velocity consensus for regulation tasks, while the bandwidth usage is only 1.25 % regarding a periodic communication implementation.[ES] Este trabajo presenta el diseño e implementación de un control colaborativo descentralizado para la sincronización de velocidad angular de un conjunto de motores de corriente continua sin escobillas (BLDC) distribuidos espacialmente. Apoyándose de un control por rechazo activo de perturbaciones, actuando como un bucle interno, la dinámica del BLDC puede asimilarse a la de un integrador de primer orden y el cual será considerado un agente. Se propone entonces una estrategia de control colaborativo descentralizado con una comunicación activada por eventos, que resuelve el problema del consenso líder-seguidor del sistema multi-agente y, con ello, la sincronización de velocidades entre motores. La topología de comunicación entre agentes se modela usando un grafo conectado y no dirigido. La ley de control descentralizado incorpora una función de evento, que indica el instante en el que $i$-ésimo agente transmite la información de velocidad angular a su vecino. El intercambio asíncrono de información permite reducir el tráfico de datos en la red de comunicaciones, lo que permite aprovechar el ancho de banda. Al analizar la dinámica de la trayectoria del error del sistema, se establece que el vector de error del sistema multi-agente tiende de forma exponencial y permanece confinado a una vecindad del origen del espacio de estados de error. Aunque la estrategia está diseñada para n-agentes, se desarrolló una plataforma experimental compuesta por dos motores y un líder virtual, permitiendo validar la estrategia. Los resultados experimentales muestran un excelente desempeño del consenso de velocidad angular de ambos motores BLDC para tareas de regulación, mientras que el uso del ancho de banda es de solamente 1.25 % con respecto a una implementación de comunicación periódica.Hernández-Méndez, A.; Guerrero-Castellanos, J.; Orozco-Urbieta, T.; Linares-Flores, J.; Mino-Aguilar, G.; Curiel, G. (2021). Comunicación distribuida activada por eventos para la sincronización de velocidad angular de motores BLDC en red. Revista Iberoamericana de Automática e Informática industrial. 18(4):360-370. https://doi.org/10.4995/riai.2021.14989OJS360370184Ahmed, N., Cortes, J., Martinez, S., 2016. Distributed control and estimation of robotic vehicle networks: Overview of the special issue-part II. IEEE Control Systems 36 (4), 18-21. https://doi.org/10.1109/MCS.2016.2558398Aranda-Escolástico, E., Guinaldo, M., Heradio, R., Chacon, J., Vargas, H., Sánchez, J., Dormido, S., 2020. 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Power active filter control based on a resonant disturbance observer. IET Power Electronics 8 (4), 554-564. https://doi.org/10.1049/iet-pel.2014.0032Garcia, E., Cao, Y., Wang, X., Casbeer, D. W., July 2015. Decentralized eventtriggered consensus of linear multi-agent systems under directed graphs. In: 2015 American Control Conference (ACC). pp. 5764-5769. https://doi.org/10.1109/ACC.2015.7172242Guerrero-Castellanos, J., Rifaï, H., Arnez-Paniagua, V., Linares-Flores, J., Saynes-Torres, L., Mohammed, S., 2018. Robust active disturbance rejection control via control lyapunov functions: Application to actuated-ankle-footorthosis. Control Engineering Practice 80, 49 - 60. https://doi.org/10.1016/j.conengprac.2018.08.008Guerrero-Castellanos, J., Vega-Alonzo, A., Durand, S., Marchand, N., Gonzalez-Diaz, V., Casta˜neda-Camacho, J., Guerrero-Sánchez, W., 2019. Leader-following consensus and formation control of vtol-uavs with eventtriggered communications. 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A backstepping approach to decentralized active disturbance rejection control of interacting boost converters. Transactions on Industry Applications 53 (4), 4063-4072. https://doi.org/10.1109/TIA.2017.2683441Lee, J., Bagheri, B., Kao, H.-A., 2015. A cyber-physical systems architecture for industry 4.0-based manufacturing systems. Manufacturing Letters 3, 18- 23. https://doi.org/10.1016/j.mfglet.2014.12.001Lewis, F. L., Zhang, H., Hengster-Movric, K., Das, A., 2013. Cooperative control of multi-agent systems: optimal and adaptive design approaches. Springer Science & Business Media. https://doi.org/10.1007/978-1-4471-5574-4Marchand, N., Durand, S., Guerrero-Castellanos, J. F., 2013. A general formula for event-based stabilization of nonlinear systems. Automatic Control, IEEE Transactions on 58 (5), 1332-1337. https://doi.org/10.1109/TAC.2012.2225493Miskowicz, M., 2015. Event-Based Control and Signal Processing. CRC Press.Neenu, T., Poongodi, P., 07 2009. 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Aflatoxins Contamination in Maize Products from Rural Communities in San Luis Potosi, Mexico

Background: Aflatoxins are a group of mycotoxins that have been associated with hepatic damage and cancer. Aflatoxins B1 and B2 are secondary metabolites produced by fungi Aspergillus. These toxins can be found in a variety of commodities, especially in maize, and have been studied around the world due to their effects in human health. The Latin American population is especially exposed to aflatoxins given that maize products can be found in traditional diets all over the continent. Interestingly, in Mexico, chronic hepatic diseases and cirrhosis are leading causes of death in adult population. Methods: In order to observe the effect of physical variables like temperature and humidity, this study was conducted collecting samples in four different seasons, in two communities in the State of San Luis Potosi, in Mexico. The content of aflatoxins in tortillas was measured using immunoaffinity columns prior to HPLC-FLD analysis. Findings: Results showed that 18% of samples exceeded the Mexican limits for AFB1; whereas, 26% of the samples exceeded the limits of the European Union for AFB1. The AFB1 was detected in 80% of samples in one site and higher concentrations were found in samples collected during fall and winter seasons. Conclusions: Lack of control in storing practices is the principal cause for the contamination of maize. Considering that maize products are part of the staple diet of Mexican population, our results show that AFB1 detection has to be declared a public health priority. Detection and prevention of aflatoxins through a surveillance program, may avoid chronic health effects.<p class="abstract"