Search

En México, la caña de azúcar (Saccharum officinarum L.) es uno de los principales cultivos que tiene una gran relevancia en el desarrollo agrícola y rural. Sin embargo, el esquema utilizado para su producción representa una fuerte problemática sobre la degradación del suelo, principalmente por el uso de productos químicos. En este sentido, el uso de biofertilizantes y diversas prácticas orgánicas representan fuertes alternativas para la mejora de la fertilidad del suelo. Por lo anterior, el presente trabajo tuvo como objetivo evaluar la efectividad de la aplicación de fertilizantes sintéticos y bioles en el crecimiento y producción de biomasa de caña de azúcar (S. officinarum) en La Candelaria, Tierra Blanca, Veracruz. Se evaluaron 6 tratamientos: Tratamiento 1, fertilización tradicional 20-10-20 ha-1 de N-P-K al momento de la siembra. Tratamiento 2, fertilización tradicional 20-10-20 ha-1 de N-P-K a 30 días después de la siembra. Tratamiento 3 fertilización tradicional al 50% 20-10-20 de NPK al momento de la siembra. Tratamiento 4 fertilización tradicional + biol a 30 días después de la siembra. Tratamiento 5 biol a 30 días después de la siembra y tratamiento 6 testigo sin aplicación. Los resultados muestran que no hay diferencias significativas entre las dosis de fertilización. Por lo tanto, el uso del biol puede ser una alternativa fertilizante para los productores de caña de azúcar y puede contribuir a la transición agroecológica del cultivo.

Heliconias belong to the group of tropical flowers, which generate economic benefits in the agricultural sector with their agronomic peculiarities. Besides providing the social actors involved with benefits aimed at sustainability in different tropical areas. Therefore, the objective of this study was to compare the physiological and agronomic characteristics of three commercial cultivars of Heliconias in three locations of a community in the municipality of Fortín, in the state of Veracruz, Mexico. Three sites were identified based on the type of agriculture: agroforestry system with Heliconias (site 1), agroforestry system - monoculture, with Heliconias (site 2) and monoculture (only Heliconias, site 3). A randomised complete block design with a split-plot arrangement (A x B) and six replications was used. Factors were: A) In situ cultivation sites, corresponding to three plots (sites) in the municipality of Coapichapan, Mexico, and B) Heliconias cultivars (Heliconia psittacorum, Heliconia wagneriana and H. bihai). The variables evaluated were tillers traits and inflorescence traits. The results show that in an agroforestry system with Heliconia, Heliconia bihai showed better performance in eight variables except for inflorescence number and bract number. In an agroforestry and monoculture system with Heliconia, Heliconia bihai shows better results in leaf length and inflorescence length. In an agroforestry system and monoculture with Heliconia, Heliconia wagneriana performed better in bract number, pseudostem width and leaf length. In monoculture, Heliconia bihai responded best to inflorescence length. Due to the tropical nature of this ornamental, the best growing conditions for Heliconia are in agroforestry systems. Due to its physiological characteristics, Heliconia bihai shows its agronomic potential in this type of agriculture even under monoculture conditions. Therefore, the conditions offered by an agroforestry system have a positive effect on the cultivation of Heliconia.

En el contexto actual de la transición agroecológica, se ha intensificado el uso de fertilizantes fermentados o bioles. El objetivo del trabajo fue comparar la concentración nutrimental de dos formulaciones de fertilizantes fermentados elaborados con insumos locales. Se diseñaron biodigestores artesanales y se utilizó estiércol de ovino y pasto Kikuyo (Pennisetum clandestinum). Se generaron dos formulaciones: Biol 1 (20% pasto kikuyo, 30% estiércol ovino y 50% agua) y Biol 2 (50% estiércol ovino y 50% agua), las cuales se fermentaron durante 100 días y se tuvieron tres repeticiones de cada formulación. En los bioles se determinó la materia orgánica y la concentración de los macronutrientes N, P y K, así como la concentración de los micronutrientes Fe, Cu, Mn y Zn. El Biol 1 tuvo mayor concentración de materia orgánica, N y Fe (P ≤ 0.05), es decir, se concluye que se mejoró la concentración nutrimental del biol cuando se agregó el pasto en el proceso de fermentación. El uso de insumos locales, de bajo costo y de fácil acceso puede ser una alternativa para producir bioles.

El deficiente manejo de los residuos sólidos urbanos se ha convertido en un grave problema de contaminación que afecta la calidad del aire, el agua y el suelo, con un impacto negativo para los seres vivos: plantas, animales y humanos. Es por ello de gran importancia el implementar estrategias de educación ambiental desde los primeros años de formación en los sistemas educativos. En México, la Secretaría del Medioambiente y Recursos Naturales (SEMARNAT) en coordinación con la Secretaría de Educación Pública (SEP) ha impulsado acciones de educación ambiental en las escuelas. El objetivo de la investigación cualitativa fue el identificar el conocimiento de los alumnos de 5°grado de educación básica en dos escuelas gubernamentales ubicadas en zonas con un nivel socioeconómico medio-bajo en la ciudad de Xalapa de Enríquez, en el estado de Veracruz sobre tópicos relacionados con la conservación del ambiente y el reciclaje como una estrategia para el manejo sustentable de los residuos urbanos. Se realizó diseño etnográfico que incluyó la encuesta y la observación como técnicas de recopilación de información para la descripción y análisis de los datos. Los resultados mostraron que los alumnos tienen un conocimiento básico sobre el manejo de los residuos y del reciclaje como acciones para la conservación de los recursos naturales, por lo que se recomendó implementar un programa de educación ambiental con el apoyo de estudiantes de la Universidad Veracruzana.

La preparación quirúrgica de machos celadores es la base para implementar esquemas de inseminación artificial en una explotación de ganado bovino bajo condiciones extensivas y/o estabuladas. Uno de los principales retos en este tipo de programas, es detectar de manera oportuna a las vacas en estro, por tanto; la función de un macho celador es facilitar esta labor, con una alta eficiencia. La correcta preparación quirúrgica y la adecuada selección de toros con las mejores características sexuales (mejor libido), mediante una técnica quirúrgica innovadora donde se consigue regresar al proceso fisiológico de la monta natural a diferencia de otras técnicas, donde el proceso quirúrgico es irreversible. El objetivo de este trabajo fue evaluar la técnica quirúrgica “penopexia perineal” en la preparación de toros marcadores para la empresa bovina. Para evaluar la técnica, se intervinieron quirúrgicamente doce bovinos de la raza suizo-cebú de 10 a 12 meses de edad, con un peso promedio de 280 Kg. Los parámetros evaluados fueron el tiempo de intervención, recuperación posoperatoria (procesos infecciosos) y retorno a la monta natural. Este estudio muestra un tiempo promedio total de 23.7 minutos y ocho días de recuperación posoperatoria, sin presencia de procesos infecciosos. Estos resultados nos permiten concluir que la utilización de esta técnica sería ventajosa en la preparación de toros marcadores.

RESUMEN Este artículo analiza los resultados del Servicio Social en una de las universidades más grandes de México, y toma como referencia los objetivos de su modelo educativo, el cual está orientado a la formación integral del estudiantado. El artículo se basa en un marco conceptual sobre el cambio curricular, la formación integral y la vinculación entre universidad y sociedad; también en el análisis de documentos institucionales y en entrevistas y cuestionarios aplicados al personal y a estudiantes. Se muestra que la ubicación del Servicio en los planes de estudio, la diversidad de perspectivas sobre sus metas y resultados, así como también una política institucional poco consistente han limitado los resultados de esta experiencia formativa tanto para los estudiantes, como para la universidad.*

Drug discovery aims at finding new compounds with specific chemical properties for the treatment of diseases. In the last years, the approach used in this search presents an important component in computer science with the skyrocketing of machine learning techniques due to its democratization. With the objectives set by the Precision Medicine initiative and the new challenges generated, it is necessary to establish robust, standard and reproducible computational methodologies to achieve the objectives set. Currently, predictive models based on Machine Learning have gained great importance in the step prior to preclinical studies. This stage manages to drastically reduce costs and research times in the discovery of new drugs. This review article focuses on how these new methodologies are being used in recent years of research. Analyzing the state of the art in this field will give us an idea of where cheminformatics will be developed in the short term, the limitations it presents and the positive results it has achieved. This review will focus mainly on the methods used to model the molecular data, as well as the biological problems addressed and the Machine Learning algorithms used for drug discovery in recent years.

La moringa es utilizada para consumo humano y animal debido a su alto contenido de proteínas, vitaminas y minerales. El presente estudio analizó y evaluó la efectividad de Azospirillum spp., sobre el contenido nutrimental de moringa (Moringa oleifera Lam.) en condiciones de vivero. El diseño experimental consistió en cuatro tratamientos con seis repeticiones en bloques completos al azar, los cuales consistieron en la inoculación a 0.5, 1 y 1.5 mL de suspensión con 9.8 × 105 UFC mL-1 de Azospirillum spp. Las variables de estudio: biomasa, proteína, macro (P, K. Ca y Mg) y micronutrimentos (Na, Fe, Cu y Mn) en hojas y tallos se determinaron a los 70 días después de la siembra. El análisis de varianza mostró diferencias estadísticas significativas entre tratamientos únicamente para las variables: contenido de potasio en hojas y contenido de calcio, fierro y sodio en tallo. De acuerdo a la comparación de medias (P ≤ 0.05) los mejores tratamientos fueron los que recibieron 0.5 y 1 mL de suspensión. La inoculación de Azospirillum, no logró aumentar el peso seco y los contenidos de proteína; sin embargo, los valores más altos (30.2% proteína cruda) se asociaron a su aplicación. La ausencia de efectos significativos en las demás variables evaluadas se asocia con la concentración del inoculo, sin embargo, se muestran valores superiores en los contenidos de nutrimentos en relación con resultados reportados en otras investigaciones.

Retail florist activities are essential elements in the rose (Rosa spp.) market since they generate significant income and employment. In these jobs, florists gain recognition by their designs that captivate consumers. At the same time, they are key entrepreneurs in the commercialization of roses. Then, the objective of the research was to know the entrepreneurial role of florists in the commercialization of roses (Rosa spp.) in southern Veracruz, Mexico. An exploratory research was conducted in flower shops, five in Coatzacoalcos, nine in Minatitlán and six in Acayucan. Interviews were conducted with florists (n = 20). The categories of analysis used were the demographic, psychosocial and sociocultural profile of the florists as innovative entrepreneurs. In regards to the demographic profile, these economic agents have the experience and knowledge necessary to develop their activity. In short, florists are identified as family micro-enterprises with establishments that are 20 years old. In the psychosocial profile, florists present low innovative capacity with respect to the composition of their floral arrangements; however, they are characterized as risk takers with the ability to solve problems. Finally, the sociocultural profile demonstrates the florists-intermediary-producers collaboration; such entrepreneurial activity generates economic incentives with local-regional influence. Therefore, florists need to strengthen their links with other florists, producers and distributors to improve their innovative capabilities that will benefit both themselves and consumers.

The agribusiness is a major generator of employment and income worldwide and contributes to food security and nutrition. Therefore, the objective was to perform a qualitative and quantitative analysis of the scientific contributions in agribusiness. A bibliographic consultation was made in Scopus and "Agribusiness" was used as keyword. A textual analysis was performed on 407 scientific papers from 2020, through Nvivo 12 software using the following analysis codes: Mega trade agreements and institutional harmonization, farm-level technology pricing and contracts, market power related to the mega consolidation of companies, new agricultural technologies, emergence of agrocorporations, institutional land access rules, property rights regimes and their consequences, private enforcement of property rights, farmer class action studies and territorial reconversion. Two more codes emerged in the analysis process: Environmental impact and human health impact. Current scientific contributions in agribusiness are focused on new agricultural technologies (24%), environmental impact (17%) and local actions of farmers (14%). A qualitative improvement of the contributions is observed as more elements that support the complex processes agribusiness generates are increasingly incorporated. From focusing on economic and financial aspects, sustainability-oriented and social commitment domains are now considered. A modern and innovative concept defines agribusiness as economic activities with different forms or models of production, derived from or linked to agricultural products. It considers production-consumption processes and farmers are inserted in a differentiated way according to their economic rationality. These activities are not only focused on the generation of monetary value, but also on the social processes it produces, where multiple actors are involved.

El objetivo fue evaluar clínica y económicamente la técnica quirúrgica modificada de traslape para corrección de hernia umbilical como estrategia productiva en empresas de producción bovina. La investigación fue de tipo experimental descriptivo. Se utilizaron 15 bovinos (2 machos y 13 hembras), peso promedio 73 kg, anillo herniario con diámetro ≤10 y ≥ 6 centímetros. Se realizó incisión elíptica con extensión de 1-2 cm en craneal y caudal respecto al anillo herniario; se continuó por las capas del tejido conectivo areolar hasta el saco herniario, se diseccionó y dejó libre hasta el margen del anillo. Posteriormente se reavivaron los bordes del anillo herniario con corte extendido de 1-1.5 cm alrededor de éste. El cierre de músculos abdominales fue mediante suturas Mayo modificadas de superposición (traslape). Se elaboraron puntos de sutura suficientes hasta la reducción total del anillo herniario. La piel se cerró con sutura interrumpida con nylon. Los indicadores demuestran que la técnica quirúrgica modificada de traslape fue eficiente al obtener una alta Relación Costo Beneficio de 4.6, y una mejoría de los becerros a los 24 días para su función zootécnica.

Background. A strategy to improve the nutritional content of moringa during its different stages of growth is through efficient fertilizers management. Objective. To evaluate the effectiveness of cutting age and fertilization in the nutritional content of moringa (Moringa oleifera Lam.). Methodology. A complete randomized block design was used with split plot arrangement (A/B) and four repetitions. Factor A: cut age, 60 and 120 days after transplantation (DAT). Factor B: soil fertilization with NPK (kg ha-1) in the doses 13-13-13 (T113), 26-26-26 (T226), 38-38-38 (T338) and control treatment without application (T4SA). The variables evaluated were: crude protein (CP), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), copper (Cu), zinc (Zn), manganese (Mn) and iron (Fe) in stems and leaves. Statistical differences were found (p ≤ 0.05) for cutting age, fertilization with NPK and the interaction between both. Results. The interaction age of cut - fertilization with NPK, showed statistical differences (p ≤ 0.05); for the K in leaves and Zn in stem. According to the means test with Tukey (p ≤ 0.05) regarding factor A, the best treatment was at 60 DDT and T113, T226 and T338 for fertilization with NPK. The best interaction was for the age of cut at 60 DDT with application of T226 and T338 for K in leaves and T113 and T338 for Zn in stem. Implications. The low doses of fertilization used in this study and the form of fertilizer distribution along the growth of moringa contribute to an efficient management of fertilizers in moringa. Conclusions. The age of cut at 60 DDT showed the highest values of nutritional content in leaves and stems. The fertilization doses applied significantly improved the nutritional values with respect to the control. The interaction between cutting age and fertilization with NPK promoted increases in nutritional values of K in leaves and Zn in Stems at the cut age of 60 DDT.

Heliconias have great commercial importance due to their durability of inflorescences, sizes, forms and bright colors. Regarding its production, the mineral nutrition of the crop is one of the most relevant aspects to obtain quality floral stems. The objective was to determine the influence of N-P-K on the growth and nutritional content of Heliconia stricta Dwarf Jamaican. A completely randomized block design was used with four treatments and five repetitions. The treatments consisted in fertilizing the soil with N-P-K. The levels of fertilization expressed in kg ha-1 of NPK were: control without application 00-00-00 (T100), 31-31-31 (T231), 62-62-62 (T362) and 93-93-93 (T493). The plants received the treatments for six months. Growth variables and nutrient contents of heliconia biomass were evaluated. The analysis of variance showed significant statistical differences (P ≤ 0.05) in the vigor and color of the plant, as well as the phosphorus, magnesium and copper contents. The significant increases in vigor and color were with doses 31- 31-31 and 62-62-62 of NPK. As for the contents of P, Mg and Cu were influenced by doses 31-31-31, 62-62-62 and 93-93-93 of NPK. This work shows important findings in relation to the nutritional diagnosis in the foliar content of nutrients.

Ensuring extension of the vase life of Heliconia commercial stems is essential for the consumer acceptance process. For this, the objective of this research was to evaluate the effect of hydration on the vase life of two Heliconia cultivars. The experimental design was in randomized blocks with subdivided plots (cultivar x hydration) with 6 replicates, being cultivars x hydration: no hydration (control), water hydration and hydration + sugar. The results considering cultivars as a factor showed a statistically significant difference (P ≤ 0.05). According to the comparison of means (P ≤ 0.05), the Heliconia psittacorum x spathorcinata tropics showed the best response. Both hydration and interaction between cultivars, showed no significant differences (P ≤ 0.05). Hydration did not guarantee a greater number of days of durability, so it is a good alternative, the use of dry treatment and the reduction on the excessive water use, according to the results obtained in this study.

En este estudio se analizó, desde la perspectiva de género, la contribución de la organización comunitaria formada por mujeres e impulsada por el Programa Oportunidades para el Desarrollo Rural Sustentable y el empoderamiento femenino de una comunidad rural en Veracruz. La metodología de análisis fue de tipo mixto (cualitativa y cuantitativa); con ello se analizó la estructura organizacional y de poder en el ejido. Los resultados obtenidos señalan que existen indicios de empoderamiento económico y de la mayor atención sobre la salud de las mujeres, aunque falta que se fortalezca el empoderamiento individual y colectivo de las mujeres, y que éste culmine en la toma de decisiones igualitarias, con injerencia directa sobre el desarrollo sustentable en el ejido.

This work summarizes the activities carried out by the SMOS (Soil Moisture and Ocean Salinity) Barcelona Expert Center (SMOS-BEC) team in conjunction with the CIALE/Universidad de Salamanca team, within the framework of the European Space Agency (ESA) CALIMAS project in preparation for the SMOS mission and during its first year of operation. Under these activities several studies were performed, ranging from Level 1 (calibration and image reconstruction) to Level 4 (land pixel disaggregation techniques, by means of data fusion with higher resolution data from optical/infrared sensors). Validation of SMOS salinity products by means of surface drifters developed ad-hoc, and soil moisture products over the REMEDHUS site (Zamora, Spain) are also presented. Results of other preparatory activities carried out to improve the performance of eventual SMOS follow-on missions are presented, including GNSS-R to infer the sea state correction needed for improved ocean salinity retrievals and land surface parameters. Results from CALIMAS show a satisfactory performance of the MIRAS instrument, the accuracy and efficiency of the algorithms implemented in the ground data processors, and explore the limits of spatial resolution of soil moisture products using data fusion, as well as the feasibility of GNSS-R techniques for sea state determination and soil moisture monitoring.

Lack of frequent and global observations from space is currently a limiting factor in many Earth Observation (EO) missions. Two potential techniques that have been proposed nowadays are: (1) the use of satellite constellations, and (2) the use of Global Navigation Satellite Signals (GNSS) as signals of opportunity (no transmitter required). Reflectometry using GNSS opportunity signals (GNSS-R) was originally proposed in 1993 by Martin-Neira (ESA-ESTEC) for altimetry applications, but later its use for wind speed determination has been proposed, and more recently to perform the sea state correction required in sea surface salinity retrievals by means of L-band microwave radiometry (TB). At present, two EO space-borne missions are currently planned to be launched in the near future: (1) ESA’s SMOS mission, using a Y-shaped synthetic aperture radiometer, launch date November 2nd, 2009, and (2) NASA-CONAE AQUARIUS/SAC-D mission, using a three beam push-broom radiometer. In the SMOS mission, the multi-angle observation capabilities allow to simultaneously retrieve not only the surface salinity, but also the surface temperature and an “effective” wind speed that minimizes the differences between observations and models. In AQUARIUS, an L-band scatterometer measuring the radar backscatter (σ0) will be used to perform the necessary sea state corrections. However, none of these approaches are fully satisfactory, since the effective wind speed captures some sea surface roughness effects, at the expense of introducing another variable to be retrieved, and on the other hand the plots (TB-σ0) present a large scattering. In 2003, the Passive Advance Unit for ocean monitoring (PAU) project was proposed to the European Science Foundation in the frame of the EUropean Young Investigator Awards (EURYI) to test the feasibility of GNSS-R over the sea surface to make sea state measurements and perform the correction of the L-band brightness temperature. This paper: (1) provides an overview of the Physics of the L-band radiometric and GNSS reflectometric observations over the ocean, (2) describes the instrumentation that has been (is being) developed in the frame of the EURYI-funded PAU project, (3) the ground-based measurements carried out so far, and their interpretation in view of placing a GNSS-reflectometer as secondary payload in future SMOS follow-on missions.

Este estudio presenta los resultados de la generación y validación de un modelo educativo, que fomenta el aprendizaje significativo y que permite auxiliar en el ingreso y permanencia de estudiantes de bachillerato en la Facultad de Ingeniería en Sistemas de Producción Agropecuaria (FISPA), y que lleva por nombre “modelo educativo FISPA-RETURETA” (MEFIR). Presenta una metodología clara y específica que consta de los siguientes puntos: 1. Diagnóstico del programa educativo 2. Demanda de estudiantes de nuevo ingreso 3. Factores limitantes 4. Elaboración del plan de trabajo 5. Reunión de difusión y participación interna con directivos, maestros y alumnos 6. Reunión con directivos de las escuelas de bachillerato para el convenio de vinculación 7. Entrevista con estudiantes participantes y 8. Validación del modelo. El estudio se centra en una serie de diagnósticos, sin embargo se operó y evaluó por medio de un plan de trabajo, donde participaron 67 estudiantes del Centro de Bachillerato Tecnológico Agropecuario No. 164 de Sayula de Alemán, Veracruz (CBTA 164), mismos que se dividieron en cuatro generaciones, del año 2009 al 2012. Los resultados fueron muy significativos, donde 73% de ellos, ingreso a la carrera mismo que rebasa en un 13% el ingreso promedio reportado para la entidad académica; así mismo, de estos estudiantes permaneció un 63%, lo que indica que solo hubo una deserción del 37%, por debajo del 50.68% reportado para la entidad académica.

La presencia reciente del Pterygoplichthys, comúnmente conocidos como plecos, pez diablo o limpia peceras, en las aguas epicontinentales de la zona de Chinameca, Veracruz, se ha convertido en un problema ecológico y ambiental, debido a que por su enorme plasticidad adaptativa y a la ausencia de depredadores naturales, provoca desplazamiento de especies nativas. Actualmente en el estado de Veracruz no se cuenta con trabajos de investigación que permitan sustentar medidas de control y/o erradicación del Pterygoplichthys. Con el objetivo de obtener datos básicos del Pterygoplichthys, se llevaron a cabo muestreos biológicos bimestrales, sobre la parte baja del río Chacalapa y la represa artesanal adyacente denominada “La Chinampita”. Los muestreos iniciaron en el mes de julio de 2012 y culminaron en mayo de 2013, se realizaron con artes de pesca poco selectivos. Se determinó la presencia de la especie P. pardalis, con individuos de 420 mm de longitud total (LT) y un peso de 620 g en los machos, en las hembras fue de 390 mm LT y 650 g. Los registros de captura que mayor abundancia de plecos presentaron, fueron en el mes de mayo con el 43%. A partir del mes de marzo se registró el inicio de la actividad reproductiva, con máximo desarrollo gonadal en mayo.

En la actualidad la producción de maíz decrece debido a la degradación de los suelos con niveles bajos de fertilidad, aunado a altos costos de producción y que además las técnicas de producción y las condiciones ambientales favorecen la presencia de plagas y enfermedades, que impacta negativamente sobre la producción. El biol es un biofertilizante que contiene microorganismos que al estar disponibles en las plantas le ayudan a su nutrición y protección (Vessey, 2003), además de ser un complemento a la fertilización tradicional, debido a la actividad microbiana de la que provienen, puede impactar positivamente sobre la sanidad de mazorcas y como tal obtener mejores rendimientos. Por lo anterior se planteó un diseño experimental con el objetivo de evaluar el rendimiento, sanidad y análisis económico de cada una de las combinaciones de biol. La investigación se llevó a cabo en Sayula de Alemán, Veracruz, se utilizó un arreglo de bloques al azar con parcelas divididas evaluándose en parcelas grandes la aplicación de biol al suelo y en parcelas chicas fertilizantes foliares a base de biol. Se obtuvo como resultados que las aplicaciones de biol + harina de ave + melaza mejoraron la sanidad de mazorcas y generó el mayor rendimiento de grano de 2.79 t ha-1, además que los menores rendimientos estuvieron asociados con los mayores porcentajes de daño a mazorcas ocasionados por el hongo Fusarium moniliforme.

Copyright of Revista Biológico Agropecuaria Tuxpan is the property of Revista Biologico Agropecuaria Tuxpan and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Soil Moisture (SM) is a key geophysical variable that enables a better understanding of the Earth’s hydrological processes. Missions like Soil Moisture Ocean Salinity (SMOS) and Soil Moisture Active Passive (SMAP) have been the primary sources of SM estimations for years. The NASA-ISRO Synthetic Aperture Radar (NISAR) mission, planned to launch in 2024, will bring L-band and S-band SAR measurements that will be used for SM estimation. Consequently, investigations to link SMAP with NISAR to produce accurate SM retrievals at improved spatial resolutions will be a focus to many research initiatives. This investigation aims to set the basis to use polarimetric Global Navigation Satellite System-Reflectometry (GNSS-R) products to enhance the temporal resolution of NISAR’s L-band SAR data through its typical 12-day period. As a proof of concept, we model SMAP radar backscatter measurements from SMAP-Reflectometry (SMAP-R) measurements, using the 3 months of data collected by the SMAP radar while it was operational. The model is based on the sensitivity of polarimetric GNSS-R to roughness, vegetation, and SM, as well as on the complementary sensitivity existing between forward and backward scatter. Different regression models are implemented using single-, dual-, and full-polarization GNSS-R measurements synthetized from SMAP-R data. This study highlights the importance of the new constellations of polarimetric GNSS-R being built and shows how those frequent measurements can serve L-band SAR missions to improve their time resolution.

The Soil Moisture Active–Passive (SMAP) mission has greatly contributed to the use of remote sensing technologies for monitoring the Earth’s land surface and estimating geophysical parameters that influence the climate system. Since the SMAP mission switched its radar receiver to allow the reception of Global Positioning System (GPS) signals, Global Navigation Satellite System Reflectometry (GNSS-R) configuration has been enabled, providing full polarimetric forward scattering measurements of the Earth’s surface, also known as SMAP Reflectometry or SMAP-R. Polarimetric GNSS-R is beneficial for sensing land surface properties, especially for more accurate estimations of soil moisture (SM) in densely vegetated areas. In this study, we explore the opportunity to enhance SMAP mission soil moisture estimates using reflected GNSS signals. We achieve this by interpolating the sparse reflectivity data with terrain information to disaggregate radiometer brightness temperatures. Our main objective is to present a novel algorithm based on Graph Signal Processing (GSP) that uses reflectometry data to enhance SMAP radiometer observations and ultimately improve SM retrievals. By implementing methods from the GSP field, we formulate the reflectivity interpolation problem as a signal reconstruction on a graph, where the weights of the edges between the nodes are chosen as a function of geophysical information. Subsequently, using the retrieved reflectivity maps, we increase the resolution of the brightness temperature data, leading to an improvement in the SM estimates. Initial findings indicate that our GSP method presents a promising alternative for analyzing sparse remote sensing observations, leveraging Earth’s surface geophysical information. This approach results in a notable improvement, with a reduced Root Mean Square Error (RMSE) of 11.8% compared to SMAP data and a reduction in unbiased RMSE (uRMSE) by 14.7% over vegetated areas.

Abstract The Soil Moisture Active Passive (SMAP) mission has dramatically benefited our knowledge of the Earth’s surface processes. The SMAP mission was initially designed to provide complementary L-band measurements from a radiometer and a radar, producing geophysical measurements at a finer spatial resolution than the radiometer alone. Both instruments, sensitive to the geophysical parameters in the swath, provided independent measurements at different spatial resolutions. A few months after SMAP’s launch, the radar transmitter’s high-power amplifier suffered an anomaly, and the instrument could no longer return data. During recovery activities, the SMAP mission switched the radar receiver frequency facilitating the reception of Global Positioning System (GPS) signals scattered off the Earth’s surface, and enabling the radar to become the first spaceborne polarimetric Global Navigation Satellite System – Reflectometry (GNSS-R) instrument. With more than 7 years of continued measurements, SMAP GNSS-R data are the most extensive existing GNSS-R dataset and the only one providing GNSS-R polarimetric measurements. We demonstrate that the SMAP polarimetric GNSS-R reflectivity, derived from Stokes parameters mathematical formulation, can enhance the radiometer data over dense vegetation areas, recovering some of the original SMAP radar capability to contribute to the science products and pioneering the first polarimetric GNSS-R mission.

This article seeks to provide a snapshot of the security of Wi-Fi access points in the metropolitan area of A Coruña. First, we discuss the options for obtaining a tool that allows the collection and storage of auditable information from Wi-Fi networks, from location to signal strength, security protocol or the list of connected clients. Subsequently, an analysis is carried out aimed at identifying password patterns in Wi-Fi networks with WEP, WPA and WPA2 security protocols. For this purpose, a password recovery tool called Hashcat was used to execute dictionary or brute force attacks, among others, with various word collections. The coverage of the access points in which passwords were decrypted is displayed on a heat map that represents various levels of signal quality depending on the signal strength. From the handshakes obtained, and by means of brute force, we will try to crack as many passwords as possible in order to create a targeted and contextualized dictionary both by geographical location and by the nature of the owner of the access point. Finally, we will propose a contextualized grammar that minimizes the size of the dictionary with respect to the most used ones and unifies the decryption capacity of the combination of all of them.

Single-pass soil moisture retrieval has been a key objective of Global Navigation Satellite System-Reflectometry (GNSS-R) for the last decade. Achieving this goal will allow small satellites with GNSS-R payloads to perform such retrievals at high temporal resolutions. Properly modeling the soil surface roughness is key to providing high-quality soil moisture estimations. In the present work, the Physical Optics and Geometric Optics models of the Kirchhoff Approximation are implemented to the coherent and incoherent components of the reflectometry measurements collected by the SMAP radar receiver (SMAP-Reflectometry or SMAP-R). Two surface roughness products are retrieved and compared for a single-polarization approach, critical for single-polarization GNSS-R instruments that target soil moisture retrievals. Then, a polarization decoupling model is implemented for a dual-polarization retrieval approach, where the ratio between two orthogonal polarizations is evaluated to estimate soil moisture. Differences between linear and circular polarization ratios are evaluated using this decoupling parameter, and the theoretical soil moisture error with varying decoupling parameters is analyzed. Our results show a 1-sigma soil moisture error of 0.08 cm3/cm3 for the dual-polarization case for a fixed polarization decoupling value used for the whole Earth, and a 2-sigma error of 0.08 cm3/cm3 when the measured reflectivity and the VOD are used to estimate the polarization decoupling parameter.

The global navigation satellite system-reflectometry (GNSS-R) field has experienced an exponential growth as it is becoming relevant to many applications and has captivated the attention of an elevated number of research scholars, research centers and companies around the world. Primarily based on the contents of two Special Issues dedicated to the applications of GNSS-R to Earth observation, this review article provides an overview of the latest advances in the GNSS-R field. Studies are reviewed from four perspectives: (1) technology advancements, (2) ocean applications, (3) the emergent land applications, and (4) new science investigations. The technology involved in the GNSS-R design has evolved from its initial GPS L1 LHCP topology to include the use of other GNSS bands (L2, L5, Galileo, etc.), as well as consider RHCP/LHCP-receiving polarizations in order to perform polarimetric studies. Ocean applications have included developments towards ocean wind speed retrievals, swell and altimetry. Land applications have evolved considerably in the past few years; studies have used GNSS-R for soil moisture, vegetation opacity, and wetland detection and monitoring. They have also determined flood inundation, snow height, and sea ice concentration and extent. Additionally, other applications have emerged in recent years as we have gained more understanding of the capabilities of GNSS-R.

This review presents a state of the art in artificial intelligence applied to urban planning and particularly to land-use predictions. In this review, different articles after the year 2016 are analyzed mostly focusing on those that are not mentioned in earlier publications. Most of the articles analyzed used a combination of Markov chains and cellular automata to predict the growth of urban areas and metropolitan regions. We noticed that most of these simulations were applied in various areas of China. An analysis of the publication of articles in the area over time is included.