Detección de Agave angustifolia y Agave cupreata con técnicas geomáticas en Guerrero, México

The agave plant has significant economic and cultural value, it is considered an agricultural and forestry product, and is also used in the production of a significant number of products. In Mexico, one of the most representative derivatives of agave are distilled beverages of mezcal and tequila, whose sales have increased outside the country. In response to this demand, Guerrero has reported an annual growth in production of 1.5 %, with an increase in area of more than 1,000 hectares between 2015 and 2020. This commercial boom has generated an expansion and intensification of planting and production of Agave spp. (Asparagaceae), as well as the use of inadequate agricultural production techniques and changes in traditional technology. That is why the objective of this work was to spatially locate the mezcal agave, in particular the species Agave cupreata Trel. & Berger and Agave angustifolia Haw., with geomatic technologies to identify the diversified environments of the agave (wild or cultivated) that strengthen the agro-productive processes and enhance the by-products of the crop. The study found that the potential area for agave cultivation is more than 25,000 hectares higher than that reported by official sources and that the calculations made with geomatic technologies have an accuracy of 91 % to identify suitable areas for the use and conservation of these two species of economic importance.La planta del agave tiene un significativo valor económico y cultural, pues no solo se considera un producto agrícola y forestal, sino que además se emplea en la elaboración de una cantidad importante de productos. En México, uno de los derivados más representativos del agave son las bebidas destiladas de mezcal y tequila, cuya venta se ha incrementado fuera del país. En respuesta a esta demanda, Guerrero ha reportado un crecimiento anual de la producción de mezcal del 1,5 %, con un aumento en la superficie de más de 1.000 hectáreas entre 2015 y 2020. Este auge comercial ha generado una expansión e intensificación de la siembra y producción de la Agave spp. (Asparagaceae), así como el uso de técnicas agrícolas de producción inadecuadas y cambios en la tecnología tradicional. Es por ello que el objetivo de este trabajo fue localizar espacialmente el agave mezcal, en particular las especies Agave cupreata Trel. & Berger y Agave angustifolia Haw., con tecnologías geomáticas para identificar los ambientes diversificados del agave (silvestre o cultivado) que fortalezcan los procesos agroproductivos y potencien los subproductos del cultivo. El estudio encontró que la superficie potencial del cultivo de agave es superior a lo reportado por fuentes oficiales en más de 25.000 hectáreas y que los cálculos realizados con tecnologías geomáticas tienen una precisión del 91 % para identificar áreas adecuadas para el aprovechamiento y la conservación de estas dos especies de importancia económica

Fast flame temperature estimation using a point diffraction interferometer and non-negative least square method

Some of the interferometry methods proposed for flame temperature measurements from its projection could be complex and demand so much computing time. Assuming a circular symmetric and smooth flame temperature distribution, it is possible to use a linear combination of Gaussian functions with weights constrained to non-negative values

La coexistencia de Desmodus rotundus con la población humana en San Luis Potosí, México

Desmodus rotundus is a transmitter of zoonotic and emerging diseases to humans and livestock, such as rabies. Most infectious diseases are spatially limited by the presence of the transmitter, whose abundance and survival are influenced by environmental conditions and the presence of food sources. A tool that facilitates its study is the use of Geographic Information Systems. The objective of this study was to analyze the interaction of populations of hematophagous bats and humans, through the development of a probable model of dispersal of D. rotundus based on known shelters and different environmental variables, in addition to analyzing the relationship between shelters identified for three years and their proximity to human settlements, as a process of coexistence. The study was conducted in the state of San Luis Potosí from 2014 to 2016. A total of 180 shelters of D. rotundus distributed towards the Huasteca region were identified, 80 % of these were built by man and 57 % were inhabited. A buffer of 5 km around from the location of each shelter was calculated, finding inside a total of 976 rural communities and 15 cities, with 337,836 inhabitants. The average distance from shelters to the first human settlement was 518.65 ± 11.33 m. It is necessary to continue studying the association between urbanization and the emergence of zoonoses, through the understanding of the interactions between wild animals-livestock-humans.Desmodus rotundus es transmisor de enfermedades zoonóticas y emergentes a los humanos y al ganado, como el caso de la rabia. La mayoría de las enfermedades infecciosas están limitadas espacialmente por la presencia del transmisor, cuya abundancia y supervivencia son influenciadas por las condiciones ambientales y la presencia de fuentes de alimentación. Una herramienta que facilita su estudio es el uso de los Sistemas de Información Geográfica. El objetivo de este estudio fue analizar la interacción de las poblaciones de murciélagos hematófagos y humanos, a través de la elaboración de un modelo probable de dispersión del D. rotundus basado en refugios conocidos y diferentes variables medioambientales, además de analizar la relación entre refugios identificados durante tres años y su cercanía con asentamientos humanos, como un proceso de coexistencia. El estudio se llevó a cabo en el estado de San Luis Potosí del año 2014 al 2016. Se identificaron un total de 180 refugios de D. rotundus distribuidos hacia la zona de la Huasteca, el 80 % de éstos fueron construidos por el hombre y el 57 % se encontraron habitados. Se calculó un buffer de 5 km a la redonda a partir de la ubicación de cada refugio, encontrando en su interior un total de 976 comunidades rurales y 15 ciudades, con 337,836 habitantes. La distancia media de los refugios hasta el primer asentamiento humano fue de 518.65 ± 11.33 m. Es necesario continuar estudiando la asociación entre la urbanización y el surgimiento de zoonosis, a través del entendimiento de las interacciones entre animales silvestres-ganadería - humanos

Análisis de riesgo potencial de Huanglongbing a través de tecnología geoespacial en Colombia

Huanglongbing (HLB) is the most destructive disease that currently impacts citrus in the world. HLB was first detected in the Americas in Brazil and then in Florida (the United States). The citrus growing areas of Colombia were free of the disease, but in April 2016, Instituto Colombiano Agropecuario (ICA) declared phytosanitary quarantine in the department of La Guajira due to the presence of HLB. At that time, the control and eradication actions were intensified; nonetheless, the report of the first half of 2018 prepared by ICA reported the presence of the HLB in six departments in northern Colombia. This study proposes a methodology to analyze the potential risk of HLB and its vector Diaphorina citri, through the use of geospatial technology, considering the location of plant hosts, the development time of the insect host in degree-days and bioclimatic variables. The results indicate that about 15 % of the citrus areas are at high risk of the presence of HLB. This method is presented as an option for monitoring the disease on a regional scale, which is also characterized by being automated, with high spatio-temporal dynamics, and can be used for early detection of the disease.Huanglongbing (HLB) es una de las enfermedades más destructivas que afecta a los cítricos en el mundo. En el continente americano, HLB se detectó primero en Brasil y posteriormente en Florida (Estados Unidos). Las áreas citrícolas de Colombia se mantuvieron libres de la enfermedad hasta que en abril de 2016 el Instituto Colombiano Agropecuario (ICA) declaró en cuarentena fitosanitaria al departamento de La Guajira por la presencia de HLB. En ese momento se intensificaron las acciones de control y erradicación; sin embargo, el informe del primer semestre de 2018 elaborado por el ICA reportó la presencia de HLB en seis departamentos del norte de Colombia. El presente estudio propone una metodología para analizar el riesgo potencial de HLB y su insecto vector Diaphorina citri mediante el uso de tecnología geoespacial, que permite determinar la ubicación de plantas hospederas, grados días de desarrollo del vector y variables bioclimáticas. Los resultados señalan que cerca del 15 % de las áreas citrícolas de Colombia se encuentra en un alto riesgo a la presencia de la enfermedad. Esta metodología se presenta como una opción para el monitoreo de la enfermedad a escala regional, ya que es automatizable y tiene una dinámica espacio-temporal alta que puede ser utilizada para la detección temprana de HLB

Phase unwrapping using a regular mesh grid

Phase unwrapping is a key step in the fringe pattern analysis. Although there are many algorithms for recovering continuous phase from wrapped phase maps, many of them are computationaly heavy, even for smooth phase maps. The smoothness characteristics of a phase map allow the use of radial basis functions to model the unwrapped phase. This method helps to reduce the processing time when unwrapping the phase. The processing time can be reduced even more when the reconstruction does not take into account all the pixels of the phase map image. In this paper we describe an algorithm for phase unwrapping where the phase map is reconstructed from a subset of pixels of the phase image using radial basis functions (RBFs). The proposed method is compared with the algorithm based on the same radial basis functions (RBFs) but using all the phase image pixels

An alternative method for phase-unwrapping of interferometric data

In this paper we present a novel algorithm for phase unwrapping where only a subset of data from the wrapped phase map is used to reconstruct the unwrapped phase map as a linear combination of radial basis functions (RBF’s). For noisy phase maps this algorithm gives better results than three reference algorithms based on radial basis functions, Zernike polynomials and path dependent phase unwrapping strategies

Evidence of spatial clustering of childhood acute lymphoblastic leukemia cases in Greater Mexico City: report from the Mexican Inter-Institutional Group for the identification of the causes of childhood leukemia

BackgroundA heterogeneous geographic distribution of childhood acute lymphoblastic leukemia (ALL) cases has been described, possibly, related to the presence of different environmental factors. The aim of the present study was to explore the geographical distribution of childhood ALL cases in Greater Mexico City (GMC).MethodsA population-based case-control study was conducted. Children <18 years old, newly diagnosed with ALL and residents of GMC were included. Controls were patients without leukemia recruited from second-level public hospitals, frequency-matched by sex, age, and health institution with the cases. The residence address where the patients lived during the last year before diagnosis (cases) or the interview (controls) was used for geolocation. Kulldorff’s spatial scan statistic was used to detect spatial clusters (SCs). Relative risks (RR), associated p-value and number of cases included for each cluster were obtained.ResultsA total of 1054 cases with ALL were analyzed. Of these, 408 (38.7%) were distributed across eight SCs detected. A relative risk of 1.61 (p<0.0001) was observed for the main cluster. Similar results were noted for the remaining seven ones. Additionally, a proximity between SCs, electrical installations and petrochemical facilities was observed.ConclusionsThe identification of SCs in certain regions of GMC suggest the possible role of environmental factors in the etiology of childhood ALL

Gestión del agua como factor limitante de productividad cañera en México

For Mexico it is fundamental to apply precise agricultural techniques in the sugarcane industry based on basic meteorological data such as precipitation, temperature and evapotranspiration in order to obtain the potential soil humidity, along with remote sensing techniques and the Normalized Difference Vegetation Index (NDVI). This study was performed during the 2008-2010 harvest seasons in the Huasteca Potosina region of Mexico. The analysis based on remote sensing techniques used NOAA-AVHRR images from satellites 17, 18 and 19 with AVHRR bands 1 (pi) (0.58 to 0.68 pm - red) and AVHRR 2 (p2) (0.72 to 1.10 pm - Near Infrared) to generate NDVI images. Simultaneously meteorological data was calculated based on data from from 11 agroclimate stations located in the study region. This data was, in turn, used to calculate the Water Requirement Satisfaction Index (WRSI). Results show a correlation between NDVI values and climatic conditions, which influence sugarcane productivity in the Huasteca Potosina region.Para México es fundamental aplicar técnicas de agricultura de precisión en la agroindustria azucarera con información meteorológica básica de precipitación, temperatura y evapotranspiración para obtener el potencial de humedad retenido por el suelo, en conjunto con percepción remota y el Índice de Diferencia Normalizada de Vegetación (NDVI). El trabajo se llevó a cabo en zafra 2008/2010 en Huasteca Potosina México. Se emplearon imágenes NOAA-AVHRR de satélites 17, 18 y 19 con bandas AVHRR 1 (p1) (0,58 a 0,68 pm - rojo) y AVHRR 2 (p2) (0,72 a 1,10 pm - infrarrojo cercano) para generar imágenes NDVI, simultáneamente se calculó a partir de registros de 11 estaciones de la zona cañera para obtener el Índice de Satisfacción de las Necesidades Hídricas de los Cultivos (ISNH). El análisis indica que existe la correlación de valores NDVI con las condiciones climáticas y que inciden en la productividad de la zafra azucarera de la Huasteca Potosina