22 research outputs found
Renewable Energies in the Agricultural Sector: A Perspective Analysis of the Last Three Years
Renewable energy arises as a tool for the supply of energy to the agriculture sector. Currently, there is a growing concern for the environment. This circumstance has led to technological progress in energy use in relation to natural resources and their availability for all productive sectors, including agriculture. The main objective of this work is to perform analysis from a bibliometric point of view and to analyze scientific advances in renewable energy and agriculture worldwide that have occurred in the last three years (2019–2021). The purpose of this study is to provide an overview of the last three years on the topic in order to contribute to the international scientific community, specifically towards collaboration between authors, institutions, and countries. A keyword analysis using community detection was applied to detect the five main clusters of this research and was largely dedicated to the following topics: renewable energy technologies in agriculture, bioenergy, sustainable agriculture, biomass energy, and the environmental impact of agriculture. The main countries found to be conducting research on renewable energy and agriculture include India, China, the United States, Italy, the United Kingdom, Poland, Indonesia, Germany, the Russian Federation, and Spain; the most important institutions conducting research in this area include the Ministry of Agriculture of the People’s Republic of China, the Tashkent Institute of Irrigation and Agricultural Mechanization Engineers at the National Research University in Uzbekistan, the Chinese Academy of Agricultural Sciences, and the Grupo de Investigação em Engenharia e Computação Inteligente para a Inovação e o Desenvolvimento in Portugal. These results may contribute to the identification of new research needs and therefore to the development of future directions of research on renewable energies in the agricultural sector
EDUCACIÓN AMBIENTAL Y SOCIEDAD. SABERES LOCALES PARA EL DESARROLLO Y LA SUSTENTABILIDAD
Este texto contribuye al análisis científico de varias áreas del conocimiento como la filosofía social, la patología, la educación para el cuidado del medio ambiente y la sustentabilidad que inciden en diversas unidades de aprendizaje de la Licenciatura en Educación para la Salud y de la Maestría en Sociología de la SaludLas comunidades indígenas de la sierra norte de Oaxaca México, habitan un territorio extenso de biodiversidad. Sin que sea una área protegida y sustentable, la propia naturaleza de la región ofrece a sus visitantes la riqueza de la vegetación caracterizada por sus especies endémicas que componen un paisaje de suma belleza
Are hermit crabs looking for light and large shells? evidence from natural and field induced shell exchanges
Terrestrial hermit crabs (Coenobita compressus (H. Milne Edwards)) on Isabel island, Mexico, prefer Nerita (Ritena) scabricosta (Lanark 1822) over other species of shells. Nerita scabricosta, the lightest species of shell, has the highest internal volume/weight ratio (IV/W ratio) of all species available at the island. Heavier shells (low IV/W ratio) are more costly to carry and may restrain growth. We hypothesized that crabs will search for shells with high IV/W ratios to save energy, and predicted that in every individual shell-exchange crabs will prefer a shell with a higher IV/W ratio. Observations of spontaneous aggressive shell-exchange interactions in nature between crabs carrying preferred shells (with high IV/W ratio) and crabs using less preferred species of shells (low IV/W ratio) support this idea. By inducing individual shell exchanges in the field, we experimentally confirmed the preference for shells with high IV/W ratio, and we also showed that crabs prefer larger shells over those they were bearing. Moving to a larger but not heavier shell may facilitate growth though saving energy that would otherwise be spent in locomotion. High growth rates seem to be advantageous because size is a correlate of fertility, since large males apparently have more access to females, and large females produce larger clutches, thus indicating the possible reproductive benefits for preferred light and large shells. (C) 1998 Elsevier Science B.V
Primer registro de oso negro americano (Ursus americanas) para el estado de Hidalgo, México
ResumenSe documenta el primer registro del oso negro americano (Ursus americanus) para el estado de Hidalgo, México, mismo que representa el punto más sureño de la distribución de esta especie. El ejemplar se encontró muerto cerca del poblado El Aguaje de Cerro Prieto en un lugar conocido como La Joya, municipio de La Misión, en el norte del estado, a una altitud de 1 48lm, probablemente correspondía a un individuo errante proveniente del estado de Querétaro.AbstractWe report the first record of American black bear (Ursus americanus) for the state of Hidalgo, Mexico; it represents the southernmost distribution record of this specie. This ursid was found death near to El Aguaje de Cerro Prieto in a locality known as La Joya, Municipality of La Misión, in the northern part of the state, at 1 48lm, probably it was an errant individual from the state of Querétaro
Propuesta de un sitio web con herramientas de gestión en línea para Institucionales de la Bahía S.A. de C.V.
"Existen muchas razones por las cuales se debería tener un sitio web. Ya que hoy en día Internet es una herramienta utilizada en todo el mundo que permite acceder a múltiples recursos y conocer con facilidad sobre una empresa o cualquier tema de interés.
An efficiency comparison of different in vitro fertilization methods: IVF, ICSI, and PICSI for embryo development to the blastocyst stage from vitrified porcine immature oocytes
Abstract Background Most studies carried out to evaluate recovery and development after porcine oocyte vitrification, reported better rates when cryopreserved in embryonic development stages or zygotes, but not in immature oocytes. For this reason, many studies are performed to improve immature oocyte vitrification protocols testing the use of different cryoprotectant concentrations, cooling devices, incubation times; but only a few of them have evaluated which fertilization procedure enhances blastocyst rates in vitrified oocytes. Therefore, this study was aimed to evaluate: 1) if the sperm selection with hyaluronic acid (HA) or polyvinylpyrrolidone (PVP) before injection could play a key role in increasing fertilization and blastocyst formation and 2) the embryo developmental ability and blastocyst production of porcine immature oocytes retrieved after vitrification-warming and co-cultured with granulosa cells during IVM, using different fertilization techniques: in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI) and conventional ICSI with hyaluronic acid (HA) sperm selection, known as physiological intracytoplasmic sperm injection (PICSI) and. Results Sperm selected with HA-PICSI displayed a higher percentage of live/acrosome reacted status compared to those in control and exposed to PVP. Higher dead/acrosome reacted rates were obtained after PVP exposure compared to control and HA. In oocytes, viability significantly decreased after IVM in vitrified oocytes. Besides, IVM rates were not different between control denuded oocytes cultured with granulosa cells (DO-GC) and vitrified oocytes. Regarding fertilization parameters, IVF showed higher percentages of total fertilization rate than those obtained by ICSI and PICSI. However, results demonstrate that PICSI fertilization increased the blastocysts formation rate in control DO-GC and vitrified oocytes compared to IVF and ICSI. Conclusions To achieve high blastocyst formation rates from vitrified GV oocytes, it is recommended that sperm should be selected with HA instead of PVP before injection since high viability and acrosome reaction rates were obtained. Also, PICSI fertilization was the best method to produce higher blastocyst rates compared to the IVF and ICSI procedures
Enhancing Ecoefficiency in Shrimp Farming through Interconnected Ponds
The future development of shrimp farming needs to improve its ecoefficiency. The purpose of this study was to evaluate water quality, flows, and nitrogen balance and production parameters on a farm with interconnected pond design to improve the efficiency of the semi-intensive culture of Litopenaeus vannamei ponds. The study was conducted in 21 commercial culture ponds during 180 days at densities of 30–35 ind m−2 and daily water exchange <2%. Our study provides evidence that by interconnecting ponds nutrient recycling is favored by promoting the growth of primary producers of the pond as chlorophyll a. Based on the mass balance and flow of nutrients this culture system reduces the flow of solid, particulate organic matter, and nitrogen compounds to the environment and significantly increases the efficiency of water (5 to 6.5 m3 kg−1 cycle−1), when compared with traditional culture systems. With this culture system it is possible to recover up to 34% of the total nitrogen entering the system, with production in excess of 4,000 kg ha−1 shrimp. We believe that the production system with interconnected ponds is a technically feasible model to improve ecoefficiency production of shrimp farming
Renewable Energies in the Agricultural Sector: A Perspective Analysis of the Last Three Years
Renewable energy arises as a tool for the supply of energy to the agriculture sector. Currently, there is a growing concern for the environment. This circumstance has led to technological progress in energy use in relation to natural resources and their availability for all productive sectors, including agriculture. The main objective of this work is to perform analysis from a bibliometric point of view and to analyze scientific advances in renewable energy and agriculture worldwide that have occurred in the last three years (2019–2021). The purpose of this study is to provide an overview of the last three years on the topic in order to contribute to the international scientific community, specifically towards collaboration between authors, institutions, and countries. A keyword analysis using community detection was applied to detect the five main clusters of this research and was largely dedicated to the following topics: renewable energy technologies in agriculture, bioenergy, sustainable agriculture, biomass energy, and the environmental impact of agriculture. The main countries found to be conducting research on renewable energy and agriculture include India, China, the United States, Italy, the United Kingdom, Poland, Indonesia, Germany, the Russian Federation, and Spain; the most important institutions conducting research in this area include the Ministry of Agriculture of the People’s Republic of China, the Tashkent Institute of Irrigation and Agricultural Mechanization Engineers at the National Research University in Uzbekistan, the Chinese Academy of Agricultural Sciences, and the Grupo de Investigação em Engenharia e Computação Inteligente para a Inovação e o Desenvolvimento in Portugal. These results may contribute to the identification of new research needs and therefore to the development of future directions of research on renewable energies in the agricultural sector