Modelo basado en redes neuronales artificiales para la evaluación de la calidad del agua en sistemas de cultivo extensivo de camarón

El cultivo de especies acuícolas es una actividad comúnmente practicada alrededor del mundo. En México, el cultivo de camarón es una de las principales fuentes de ingresos en el área de la acuicultura. La calidad del agua es un factor relevante en el éxito del cultivo en granjas camaronícolas, por lo que su monitoreo resulta ser de vital importancia. Este estudio presenta un nuevo modelo computacional para la evaluación de la calidad del agua en granjas de cultivo extensivo para camarón Litopenaeus vannamei. Mediante el uso de las redes neuronales artificiales se creó un indicador de la calidad del agua, mismo que permite establecer una relación entre la dinámica de los parámetros del ecosistema y diferentes estados para el cultivo de la especie (excelente, bueno, regular y deficiente). Se seleccionaron cuatro parámetros medioambientales debido a su importancia en el hábitat: temperatura del agua, pH, oxígeno disuelto y salinidad. Los resultados obtenidos muestran un buen funcionamiento y eficiencia por parte del sistema propuesto, al compararlo con otros modelos de evaluación empleados para este fin. Las evaluaciones muestran a las RNA como una buena opción para la evaluación y detección de estados óptimos o no deseados para un buen manejo del agua en este tipo de cultivos

Caracterización de los sistemas de producción familiar ovina en la Mixteca Oaxaqueña, México

Family sheep production is common in rural Mexico. It is an important element of subsistence systems in these areas but is generally rustic. Better understanding of rustic sheep production is a first step in developing strategies and programs to support family producers. Family sheep production units in two municipalities in the Mixteca region of Oaxaca, Mexico, were characterized in terms of production system, market access and land use. A mixed methodology was applied, employing a structured questionnaire addressing socioeconomic and productive variables, and participatory observation in 29 family sheep producers. All the surveyed producers see sheep farming as their main income source. Most (86 %) use a subsistence system, and all use family labor. The main feeding strategy was grazing of communal land, and production was largely intended for sale of live animals to intermediaries or in local markets for eventual processing for meat, and/or for self-use. Most (83 %) of the production units included a pen built from regional materials, and these pens were most frequently on the family property. Implementation of management plans and animal health and safety measures were minimal. Analysis of these productive systems identified how producers manage sheep production. Management strategies respond to the environmental services available on communal lands, and involve family-type production which fulfills economic, social, environmental and cultural functions, but provides low productivity. Unit productivity and producer livelihood could be improved by implementing measures such as pasture rotation and adopting technological innovations. Broadening producer access to government programs and creating public policy that promotes development in marginal rural areas could greatly improve productivity and consequently reduce poverty and food insecurity.El objetivo fue analizar las características de las unidades de producción familiar ovina de dos municipios de la Mixteca Oaxaqueña teniendo como referencia el sistema de producción, acceso al mercado y el uso del territorio. Se usó una metodología mixta, empleando un cuestionario estructurado donde se analizaron variables de carácter socioeconómico y productivo; y observación participativa en 29 ovinocultores familiares. Los resultados señalan que el 100 % de los productores ven a la ovinocultura como principal fuente de ingresos, 86 % produce bajo un sistema de subsistencia, 100 % emplea la mano de obra familiar, la estrategia alimentaria principal es el pastoreo debido a las características del territorio y el tipo de tenencia de la tierra comunal en un 90 %, la función zootécnica es producción de carne destinada al comercio local y autoconsumo, 83 % de los productores cuentan con corral de encierro construido con material de la región, 86.7 % de los productores mantienen su corral dentro del predio familiar, se aplican escasas medidas de manejo y sanitarias. El análisis de los sistemas productivos permitió identificar formas de gestión de su producción la cual está ligada a los servicios dentro de su territorio, desarrollando una producción de tipo familiar que cumple con funciones económicas, sociales, ambientales y culturales, sin embargo, se cuenta con una baja productividad. Por lo cual, se considera necesario la adopción de tecnología e innovación a través de estrategias y políticas públicas que impulsen el desarrollo rural en zonas marginales tendientes a disminuir el nivel de pobreza e inseguridad alimentaria

Chemical composition and in situ ruminal disappearance of sorghum silages grown in the mexican humid tropic

The purpose was to evaluate the chemical composition and in situ ruminal dry matter disappearance of four types of grain sorghum silages, one brown midrib sorghum (bmr) and, a corn silage, grown under rainfed conditions in a humid tropical region of Mexico. The crops were established at three sites. At harvest, three minisilos per treatment were filled with forage previously chopped. Minisilos opened at 55 days and samples of silage taken to dry and ground to 1 mm to determine the chemical composition and in situ ruminal dry matter disappearance. The crude protein was higher (p<0.05) in sorghum silages than corn silage. In sorghum silages, bmr sorghum had the lowest (p0.05) in ADF and ADL to corn silage. The degradation parameters (a, b, c ) was higher (p0.05) in bmr sorghum and corn silages. In the humid tropics, bmr sorghum silages are a good alternative to corn silage, especially in the dry season.The purpose was to evaluate the chemical composition and in situ ruminal dry matter disappearance of four types of grain sorghum silages, one brown midrib sorghum (bmr) and, a corn silage, grown under rainfed conditions in a humid tropical region of Mexico. The crops were established at three sites. At harvest, three minisilos per treatment were filled with forage previously chopped. Minisilos opened at 55 days and samples of silage taken to dry and ground to 1 mm to determine the chemical composition and in situ ruminal dry matter disappearance. The crude protein was higher (p<0.05) in sorghum silages than corn silage. In sorghum silages, bmr sorghum had the lowest (p0.05) in ADF and ADL to corn silage. The degradation parameters (a, b, c ) was higher (p0.05) in bmr sorghum and corn silages. In the humid tropics, bmr sorghum silages are a good alternative to corn silage, especially in the dry season. &nbsp

Effect of cutting height, a bacterial inoculant and a fibrolytic enzyme on corn (Zea mays L.) silage quality

This study aimed to evaluate cutting height (CH) effects on ensiled corn without additives (C), with a lactic acid bacteria inoculant (L), a fibrolytic enzyme (F), or a mixture of both (FL), considering chemical composition and both in vitro digestibility dry matter (IVDMD) and in vitro neutral detergent fiber (IVNDFD). Corn was harvested at three different cutting heights (12, 25 or 42 cm above the soil) and ensiled with or without additives (AD). Data was analyzed according to a factorial design, with a 3 x 4 arrangement of treatments and three repeats. Dry matter content was highest in C12 and lowest in F12 (P<0.05) silages. As cutting height was higher, cell wall content was lower (P<0.05). Even considering it increased after the use of additives (P<0.05), the highest values occurred with FL silages. Crude protein was equal (P˃0.05) between CH and increased (P<0.05) with AD. The highest IVDMD was observed for 42 cm CH, while IVDMD and IVNDFD were higher in C and F, but lower with FL. None of the inoculation treatments, alone or combined improved corn silage quality. In fact, FL combination decreased such quality. Highlights: The efficacy of lactic acid bacteria (LAB) and exogenous fibrolytic enzyme (EFE) is a funtion of the amount of cell walls and sugars present in the maize plant at harvest. Adding LAB and EFE to maize forage harvested at different cutting heights did not improve silage quality, in fact, the combination of both additives decreased silage quality. Further studies are needed to prove the efficacy of EFE and its combination with LAB on maize silage quality.This study aimed to evaluate cutting height (CH) effects on ensiled corn without additives (C), with a lactic acid bacteria inoculant (L), a fibrolytic enzyme (F), or a mixture of both (FL), considering chemical composition and both in vitro digestibility dry matter (IVDMD) and in vitro neutral detergent fiber (IVNDFD). Corn was harvested at three different cutting heights (12, 25 or 42 cm above the soil) and ensiled with or without additives (AD). Data was analyzed according to a factorial design, with a 3 x 4 arrangement of treatments and three repeats. Dry matter content was highest in C12 and lowest in F12 (P<0.05) silages. As cutting height was higher, cell wall content was lower (P<0.05). Even considering it increased after the use of additives (P<0.05), the highest values occurred with FL silages. Crude protein was equal (P˃0.05) between CH and increased (P<0.05) with AD. The highest IVDMD was observed for 42 cm CH, while IVDMD and IVNDFD were higher in C and F, but lower with FL. None of the inoculation treatments, alone or combined improved corn silage quality. In fact, FL combination decreased such quality. Highlights: The efficacy of lactic acid bacteria (LAB) and exogenous fibrolytic enzyme (EFE) is a funtion of the amount of cell walls and sugars present in the maize plant at harvest. Adding LAB and EFE to maize forage harvested at different cutting heights did not improve silage quality, in fact, the combination of both additives decreased silage quality. Further studies are needed to prove the efficacy of EFE and its combination with LAB on maize silage quality.

Yield and quality of Guinea grass cv. Mombasa according to plant spacing and season of the year

Objective: The purpose was to evaluate the yield, chemical composition and in vitro digestibility of Guinea grass (Megathyrsus maximus, Jacq.) cv. Mombasa according to plant spacing and seasons of the year. Design/methodology/approach: The Mombasa grass was stablished at plants spacing: 25x25. 50x25, 70x25 and 100x25 cm between rows and plants, respectively, and broadcasting (traditional planting); and cutting in: cool, dry and rainy seasons. There was used a factorial split-plot design into randomized blocks, with four replications. Results: The dry matter yield (DMY) was equal (p˃0.05) in cool and rainy seasons and lower (p<0.05) in dry season (27.2, 27.5 and 12.7 kg ha-1 d-1, respectively). The crude protein (CP) increased at longer plant spacing (p<0.05). The regrowth of the dry season showed a higher (p<0.05) CP than cool or rainy seasons (10.5, 9.7 and 8.7%). The content of all fiber fractions, except lignin, did not differ between plant spacing (p>0.05). Limitations on study/implications: The season of the year affects the quality of tropical grasses. On the other hand, there is no information of plant spacing on the quality of Mombasa grass. Findings/conclusions: The highest DMY was in cool season at 75x25 cm and 100x25 cm. The regrowth of the dry season showed lower fiber content and greater in vitro digestibility, but lower DMY. To ensure proper yield and quality, it is recommended to establish the Guinea grass cv. Mombasa at longer plant spacing, such as 75x25 cm or 100x25 cm.Objective: The purpose was to evaluate the yield, the chemical composition and the in vitro digestibility of Guinea grass (Megathyrsus maximus, Jacq.) cv. Mombasa according to plant spacing and season of the year. Design/methodology/approach: The Mombasa grass was stablished at spacing between plants of: 25x25, 50x25, 70x25 and 100x25 cm between rows and plants, respectively, and with broadcasting (traditional planting); cutting was conducted in cool, dry and rainy seasons. A factorial split-plot design in randomized blocks was used, with four replications. Results: The dry matter yield (DMY) of Mombasa grass was equal (p˃0.05) in cool and rainy seasons and lower (p<0.05) in dry season (27.2, 27.5 and 12.7 kg ha-1 d-1, respectively). The crude protein (CP) increased with greater plant spacing (p<0.05). The fodder of the dry season showed a higher (p<0.05) CP content than cool or rainy seasons (10.5, 9.7 and 8.7%). The content of all fiber fractions, except lignin, did not differ between plant spacing (p>0.05). Study limitations/implications: The season of the year affects the quality of tropical grasses. On the other hand, there is no information about the effect of plant spacing on the quality of Mombasa grass. Findings/conclusions: The highest DMY was in the cool season at 75x25 cm and 100x25 cm. The fodder harvested in the dry season showed lower fiber content in cell walls and higher in vitro digestibility (p˂0.05), but lower DMY. To ensure proper yield and quality, it is recommended to establish the Guinea grass cv. Mombasa at greater plant spacing, such as 75x25 cm or 100x25 cm

Incidence of COVID-19 in Children and Young People Who Play Federated Football

[Abstract] Aim: To determine the incidence of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection in children and young people who play federated football. Methods: Prospective study, from October 2020 to January 2021, in players aged 4 to 19 years from federated football clubs in Galicia, Spain (N = 23,845). Outbreaks and cases of SARS-CoV-2 infection were recorded. The cumulative incidence was compared with the incidence registered in Galicia in the same age range. Results: The cumulative incidence was 29.8 cases per 10,000 licenses in 4 months, lower than the incidence registered in the general population for all ages and both sexes (283.7 per 10,000 inhabitants; rate ratio = 9.5). It was higher in January (40.7 per 10,000), coinciding with the population peak. More cases were registered in futsal (42.9 vs 27.5 per 10,000) and competitions with periodic screenings (127.4 vs 9.1 per 10,000). There were 2 outbreaks in 2389 teams (0.08%). Conclusion: The results support the safety of football practice in children and young people with prevention protocols

Health status and productivity of sheep fed coffee pulp during fattening

The objective of this study was to evaluate the productivity and health of fattening lambs fed different levels of coffee pulp in their diets. Thirty-five crossbred lambs with an average weight of 21.8 kg were fed isoproteic and isoenergetic diets with different percentages of coffee pulp (T0: control; T1: 7%; T2: 14%, T3: 21% and T4: 28%), the base diet was formulated with corn, soybean meal, alfalfa stubble, molasses, urea and mineral salt. The fattening period was 98 days. Productivity was measured by weight gain, feed intake and feed conversion. At the beginning and end of the study, blood samples were taken to determine the health status using a biochemical profile and blood count. Analysis of variance was performed using the initial weight as the covariate for the productive variables and the initial values of the analytes in the blood chemistry and hematological analysis tests. The coffee pulp did not affect productivity, although the amount of neutrophils decreased (P<0.05) as the coffee pulp in the diet increased. In all treatments, urea exceeded the reference values, whereas creatinine was below the reference values. We concluded that the inclusion of up to 28% coffee pulp in the diet did not affect the productive parameters, decreases the neutrophil count without affect health status of lambs during fattening

La cobertura de la prensa en torno a la inseguridad migratoria durante elecciones presidenciales

A retrospective study was carried out with a selected sample of briefing notes in the press with national circulation. Based on the Establishment Setting Theory (EST) and its cycle of mediatization, an Index of Mediatization of Migratory Insecurity (IMMI) was built to measure the bias of the print media on the subject. The results show that the coverage of the migratory insecurity, during the period of September 2011 to April 2012 is low. The findings are discussed in the light of the TEA and its cycle of mediatization.La relevancia de la inseguridad migratoria parece cobrar un mayor auge en coyunturas tales como las elecciones presidenciales o parlamentarias en las que los pre-candidatos o candidatos insertan en su plataforma proselitista, el tema de la migración en referencia a la seguridad nacional. Tal proceso sociopolítico electoral es cubierto en mayor o menor medida por los medios de comunicación que, en el caso particular de la elección presidencial de México, parece corresponder con las pre-campañas internas en las cuales el tema de la inseguridad ha sido ubicua en lo general, pero soslayada la inseguridad migratoria en lo particular. En este sentido, se llevó a cabo un estudio retrospectivo con una muestra seleccionada de notas informativas en la prensa de circulación nacional. A partir de la Teoría del Establecimiento de la Agenda (TEA) y su ciclo de mediatización, se construyó un Índice de Mediatización de Inseguridad Migratoria (IMIM) para medir el sesgo de los medios impresos sobre la temática. Los resultados muestran que la cobertura de la inseguridad migratoria, durante el periodo que va de septiembre de 2011 a abril de 2012 es baja. Los hallazgos son discutidos a la luz de la TEA y su ciclo de mediatización

Ready Access to Molecular Rotors Based on Boron Dipyrromethene Dyes-Coumarin Dyads Featuring Broadband Absorption

Herein we report on a straightforward access method for boron dipyrromethene dyes (BODIPYs)-coumarin hybrids linked through their respective 8- and 6- positions, with wide functionalization of the coumarin fragment, using salicylaldehyde as a versatile building block. The computationally-assisted photophysical study unveils broadband absorption upon proper functionalization of the coumarin, as well as the key role of the conformational freedom of the coumarin appended at the meso position of the BODIPY. Such free motion almost suppresses the fluorescence signal, but enables us to apply these dyads as molecular rotors to monitor the surrounding microviscosity.This research was funded by Spanish Ministerio de Economia y Competitividad (project MAT2017-83856-C3-3-P), Gobierno Vasco (project IT912-16), CONACyT (grants 253623, 123732) and Dirección de Apoyo a la Investigación (DAIP-UG CIIC318/2019)