Respuesta del tomate (Solanum lycopersicum L.) al consumo hídrico, área foliar y rendimiento con respecto al número de tallos

The objective of this study was to analyze tomato responses to water requirements (evaluated by means of balance lysimeters), leaf area, yield, quality and its relationship with weather, depending on the number of stems. The work was carried out in a greenhouse under hydroponic conditions. Tezontle (Stuff) was used as a substrate and a drip irrigation system was installed. The experiment consisted of three treatments, with one (T1), two (T2) and three (T3) stems per plant. The daily crop evapotranspiration was 0.30 L m-2 in the initial stage, up to 4.41, 4.77 and 6.0 L m-2, in the stage of maximum demand for T1, T2 and T3. The gross volume applied throughout the cycle was 352.2, 388.4 and 434.7 L m-2 for T1, T2 and T3, with productivities of 49, 41 and 36 kg m3 and yields of 20, 18 and 16 kg m-2 for T1, T2 and T3. Regarding quality parameters in size, T1 was the best, with 69, 23, 8 and 1% fruits of first, second, third and small fruits per plant respectively. The meteorological variables such as; temperature, wind, relative humidity, vapor pressure deficit and atmospheric water potential determined the consumption of water and nutrients in crops and are variables for irrigation scheduling.El objetivo de este estudio fue analizar las respuestas del jitomate a los requerimientos hídricos (evaluado por medio de lisímetros de balance), área foliar, rendimiento, calidad y su relación con el tiempo atmosférico, en función del número tallos. El trabajo se realizó en un invernadero en condiciones de hidroponía. Se utilizó tezontle como sustrato y un sistema de riego por goteo. El experimento consistió en tres tratamientos, con uno (T1), dos (T2) y tres (T3) tallos por planta. El consumo por evapotranspiración diaria del cultivo fue 0,30 L m-2 en la etapa inicial, hasta 4,41, 4,77 y 6,0 L m-2 en la etapa de máxima demanda para T1, T2 y T3. El volumen bruto aplicado durante todo el ciclo fue 352,2; 388,4 y 434,7 L m-2 para T1, T2 y T3, con productividades de 49, 41 y 36 kg m3 y rendimientos de 20, 18 y 16 kg m-2 para T1, T2 y T3. Con relación a los parámetros de calidad en tamaño, el T1 fue mejor, con 69, 23, 8 y 1% frutos de primera, segunda, tercera y frutos pequeños por planta. Las variables meteorológicas como temperatura, viento, humedad relativa, déficit de presión de vapor y potencial hídrico atmosférico determinan el consumo de agua y nutrimentos en los cultivos y son variables para calendarización del riego

Respuesta del tomate (Solanum lycopersicum L.) al consumo hídrico, área foliar y rendimiento con respecto al número de tallos en invernadero

The objective of this study was to analyze tomato responses to water requirements (evaluated by means of balance lysimeters), leaf area, yield, quality and its relationship with weather, depending on the number of stems. The work was carried out in a greenhouse under hydroponic conditions. Tezontle (Stuff) was used as a substrate and a drip irrigation system was installed. The experiment consisted of three treatments, with one (T1), two (T2) and three (T3) stems per plant. The daily crop evapotranspiration was 0.30 L m-2 in the initial stage, up to 4.41, 4.77 and 6.0 L m-2, in the stage of maximum demand for T1, T2 and T3. The gross volume applied throughout the cycle was 352.2, 388.4 and 434.7 L m-2 for T1, T2 and T3, with productivities of 49, 41 and 36 kg m3 and yields of 20, 18 and 16 kg m-2 for T1, T2 and T3. Regarding quality parameters in size, T1 was the best, with 69, 23, 8 and 1% fruits of first, second, third and small fruits per plant respectively. The meteorological variables such as; temperature, wind, relative humidity, vapor pressure deficit and atmospheric water potential determined the consumption of water and nutrients in crops and are variables for irrigation scheduling.El objetivo de este estudio fue analizar las respuestas del jitomate a los requerimientos hídricos (evaluado por medio de lisímetros de balance), área foliar, rendimiento, calidad y su relación con el tiempo atmosférico, en función del número de tallos. El trabajo se realizó en un invernadero en condiciones de hidroponía. Se utilizó tezontle como sustrato y un sistema de riego por goteo. El experimento consistió en tres tratamientos, con uno (T1), dos (T2) y tres (T3) tallos por planta. El consumo por evapotranspiración diaria del cultivo fue 0,30 L m-2 en la etapa inicial, hasta 4,41, 4,77 y 6,0 L m-2 en la etapa de máxima demanda para T1, T2 y T3. El volumen bruto aplicado durante todo el ciclo fue 352,2; 388,4 y 434,7 L m-2 para T1, T2 y T3, con productividades de 49, 41 y 36 kg m3 y rendimientos de 20, 18 y 16 kg m-2 para T1, T2 y T3. Con relación a los parámetros de calidad en tamaño, el T1 fue mejor, con 69, 23, 8 y 1% frutos de primera, segunda, tercera y frutos pequeños por planta. Las variables meteorológicas como temperatura, viento, humedad relativa, déficit de presión de vapor y potencial hídrico atmosférico determinan el consumo de agua y nutrimentos en los cultivos y son variables para calendarización del riego.Fil: Mendoza-Pérez, Cándido. Colegio de Postgraduados. Campus Montecillo (México)Fil: Ramírez-Ayala, Carlos. Colegio de Postgraduados. Campus Montecillo (México)Fil: Ojeda-Bustamante, Waldo. Instituto Mexicano de Tecnología del Agua (Morelos, México).Fil: Trejo, Carlos. Colegio de Postgraduados. Campus Montecillo (México)Fil: López-Ordaz, Anselmo. Texcoco (México). Colegio de PostgraduadosFil: Quevedo-Nolasco, Abel. Colegio de Postgraduados. Campus Montecillo (México)Fil: Martínez Ruiz, Antonio. Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (México

Post-ejaculation incubation of semen as a method to alter the sex ratio of offspring obtained by artificial insemination in rabbits

In mammals, the sex ratio under natural conditions is 50% female and 50% male. However, this ratio can be altered by some methods. The application of warmth (42ºC) to the scrotum has an effect on the functioning of spermatozoa within the epididymis and modifies the sex ratio of offspring obtained through natural mating. The aim of this study was to determine the effect of post-ejaculation incubation temperature (42ºC or 30ºC) on the sex ratio of offspring obtained by artificial insemination. Each ejaculate was diluted and divided into two equal aliquots (0.5mL), one of which was incubated at 42ºC and the other at 37ºC for 30min. The sperm motility and viability at 42ºC was 87.3% and 89.4%, and at 37ºC, 88.2 and 75.5%, respectively. When artificial insemination was performed using semen incubated at 42ºC and 37ºC, 6.38, and 7.83 connies were born per litter, respectively. The sex ratio of offspring when sperm was incubated at 42ºC was 56.2% females and 43.7% males, while for semen incubated at 37ºC it was 52.6% females and 47.4% males. In conclusion, incubation of semen post ejaculation at 42ºC for 30 min could be used to favor the birth of female offspring through artificial insemination

Uso del agua en la alfalfa (Medicago sativa) con riego por goteo subsuperficial

The present study was carried out at the Comarca Lagunera, located astride the States of Coahuila and Durango, Mexico, in 2004 in order to analyze water use efficiency in two irrigation systems, subsurface drip and border, in alfalfa. A completely randomized block design with four replications and three treatments for distance between irrigation tapes at 0.8, 0.9 and 1.0 m was established.Con el objetivo de analizar la eficiencia en el uso del agua con el sistema de riego por goteo subsuperficial y por gravedad, durante el año 2004 se realizó la investigación en la Comarca Lagunera de los estados de Coahuila y Durango, México. Se estableció un diseño de bloques al azar con cuatro repeticiones y tres tratamientos de separación de cintas de riego de 0.8, 0.9 y 1.0 m, y como testigo se evaluó el método de riego por gravedad

4to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

Este volumen acoge la memoria académica de la Cuarta edición del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2017, desarrollado entre el 29 de noviembre y el 1 de diciembre de 2017 y organizado por la Universidad Politécnica Salesiana (UPS) en su sede de Guayaquil. El Congreso ofreció un espacio para la presentación, difusión e intercambio de importantes investigaciones nacionales e internacionales ante la comunidad universitaria que se dio cita en el encuentro. El uso de herramientas tecnológicas para la gestión de los trabajos de investigación como la plataforma Open Conference Systems y la web de presentación del Congreso http://citis.blog.ups.edu.ec/, hicieron de CITIS 2017 un verdadero referente entre los congresos que se desarrollaron en el país. La preocupación de nuestra Universidad, de presentar espacios que ayuden a generar nuevos y mejores cambios en la dimensión humana y social de nuestro entorno, hace que se persiga en cada edición del evento la presentación de trabajos con calidad creciente en cuanto a su producción científica. Quienes estuvimos al frente de la organización, dejamos plasmado en estas memorias académicas el intenso y prolífico trabajo de los días de realización del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad al alcance de todos y todas

The biodiversity of fishes at the Islas Marías Biosphere Reserve, Mexico, as determined by baited remote underwater video

The Islas Marías Biosphere Reserve, made up of 4 islands in Pacific waters off central Mexico, supports a large diversity of marine life. However, scientific research was restricted for decades by the occupation of Isla María Madre by the Federal Penitentiary Colony of Mexico from 1905 to 2019. Aside from a list of coastal fish species published in 2011, little has been published about the fish biodiversity in the area. While the limited access to the archipelago may have acted as a de-facto marine reserve, there is evidence that fishing continued both legally for the benefit of the colony and illegally by trespassing vessels. In order to establish baseline ecological data for future conservation planning, we used baited remote underwater video (BRUV) surveys at all 4 islands during 3 expeditions to the archipelago in 2018. A total of 131 BRUV surveys representing ~150 h of footage were analyzed to create the most current compilation of species and abundance data on coastal marine fishes at Islas Marías. Ninety-nine species were identified, 3 of which were additions to the previous assessment. We found strong separation of fish communities based on both habitat and depth, and an association between hard-bottom habitats and high biodiversity of reef fishes. With the declaration of Islas Marías as a natural reserve and relocation of the prison in 2019, there is an opportunity for the reserve to become a priority area for marine conservation on the Pacific coast of Mexico. Spatial analyses of fish biodiversity at Isla María Cleofas can help develop sustainable management strategies at a time when the governmental jurisdiction of the iconic archipelago is uncertain

Description of first nursery area for a pygmy devil ray species (Mobula munkiana) in the Gulf of California, Mexico.

Munks pygmy devil rays (Mobula munkiana) are medium-size, zooplanktivorous filter feeding, elasmobranchs characterized by aggregative behavior, low fecundity and delayed reproduction. These traits make them susceptible to targeted and by-catch fisheries and are listed as Vulnerable on the IUCN Red List. Multiple studies have examined fisheries impacts, but nursery areas or foraging neonate and juvenile concentrations have not been examined. This study describes the first nursery area for M. munkiana at Espiritu Santo Archipelago, Mexico. We examined spatial use of a shallow bay during 22 consecutive months in relation to environmental patterns using traditional tagging (n = 95) and acoustic telemetry (n = 7). Neonates and juveniles comprised 84% of tagged individuals and their residency index was significantly greater inside than outside the bay; spending a maximum of 145 consecutive days within the bay. Observations of near-term pregnant females, mating behavior, and neonates indicate an April to June pupping period. Anecdotal photograph review indicated that the nursery area is used by neonates and juveniles across years. These findings confirm, for the first time, the existence of nursery areas for Munks pygmy devil rays and the potential importance of shallow bays during early life stages for the conservation of this species

Regulatory T Cells: Molecular Actions on Effector Cells in Immune Regulation

T regulatory cells play a key role in the control of the immune response, both in health and during illness. While the mechanisms through which T regulatory cells exert their function have been extensively described, their molecular effects on effector cells have received little attention. Thus, this revision is aimed at summarizing our current knowledge on those regulation mechanisms on the target cells from a molecular perspective

Manta and devil ray aggregations: conservation challenges and developments in the field

Manta and devil rays (mobulids) are filter feeding elasmobranchs with extreme K-selective life histories found circumglobally from temperate to tropical waters. Their vulnerability to fisheries exploitation, bycatch, boat collisions, entanglement and unregulated tourism is exacerbated by their aggregative behavior. Studies have identified aggregation sites around the world for all nine mobulid species, with these groupings varying from a few individuals to thousands. However, the terminology used to define these aggregations and the drivers underpinning them remain unclear, hindering the development of effective management and conservation strategies. Here, we analyze aggregation behavior for mobulid species, providing consistent definitions for grouping events and summarizing the existing research on drivers and environmental factors triggering these events. We find that aggregation behaviors facilitate socializing and key life history functions in mobulids, including feeding, courtship and mating, predation avoidance, cleaning, and thermoregulation. Conservation threats and management mitigation opportunities associated with aggregations sites include fisheries, tourism, spatial protection, and climate change. Finally, we highlight knowledge gaps for future research prioritization and developments in the field for the identification of aggregation sites, the study of aggregation size and demographics and the functions and timing of aggregations