Breve caminata por La moral es infiel

Obras como La moral es infiel (2022, San José, EUNED, 440 págs.) deben celebrarse. En eso y otros aspectos acierta el Prof. Dr. Roberto Castillo en su magnífico prólogo, pues el filósofo Álvaro Zamora asume “con rigor” una serie de “cuestiones medulares del pensamiento filosófico” de Jean Paul Sartre y abre las puertas a muchos temas que pueden motivar el interés de colegas suyos y de otras especialidades que se encuentren interesados en cuestiones de la ética, en estudios sobre el ejercicio cotidiano de la palabra, de la vecindad y la colaboración humana, así como del amor o de cualquier sentimiento mutuo, de las pasiones, o incluso de la metodología para abordar problemas antropológicos

Physical and chemical properties of soils irrigated with vinasses for the cultivation of sugarcane (Saccharum spp.) in the central region of Veracruz, Mexico

Objective: To evaluate the physical and chemical properties of a soil with vinasse application (two years) (V), compared to a soil without vinasse (W/V). Design/methodology/approach: In both agroecosystems, the evaluated parameters were texture, pH, electrical conductivity (EC), organic matter (OM), phosphorus (P), potassium (K), nitrates (NO3) and total nitrogen (TN) according to standardized methods in NOM-021-SEMARNAT-2000. Results: There were no significant changes (p>0.05) in the pH and electrical conductivity, however, the application of vinasse significantly increased (p˂0.05) the content of TN (1.52%), K (112.00 mg L-1) and OM (4.52%) in relation to soils W/V (0.78%, 25.60 mg L-1, 7.40 mg L-1, 2.75%, respectively). Limitations on study/implications: In Veracruz state, there are few studies that allow knowing the contributions, and physical and chemical effects on soils irrigated with vinasses. Findings/conclusions: Even though, the vinasse used showed a positive effect on the physical and chemical characteristics of the soil (V), the mineral fertilization program must be reformulated to increase the concentration of potassium and phosphorus in soils with silt loam texture. In addition, it is recommended to adjust and normalize the dose of N that vinasse can provide instead of conventional fertilizers. Keywords: Soil fertility, sugarcane, vinasses.Objective: To evaluate the physical and chemical properties of a soil irrigated with vinasse for two years (+V), compared with a soil without vinasse (-V) application.Design/Methodology/Approach: The following parameters were evaluated for both agroecosystems: texture, pH, electrical conductivity (EC), organic matter (OM), phosphorus (P), potassium (K), nitrate (NO 3 ), and total nitrogen (TN). The evaluation followed the standardized methods established in NOM-021-SEMARNAT-2000.Results: There were no significant changes (p > 0.05) in the soil’s pH and electrical conductivity. However, the application of vinasse significantly increased (p < 0.05) the concentrations of TN (1.52%), K (112.00 mg L -1 ), and OM (4.52%) in relation to soils - V (0.78%, 25.60 mg L -1 , 7.40 mg L-1 , and 2.75%, respectively). Study Limitations/Implications: There are few studies about the contributions and the physical and chemical effects of soil irrigation with vinasses in the State of Veracruz.Findings/Conclusions: Even though vinasse had a positive effect on the physical and chemical characteristics of the soil, the mineral fertilization program must be reformulated to increase the K and P concentration in soils with silt loam texture. In addition, we recommend adjusting and normalizing the dose of N that vinasse can provide to complement conventional fertilizers

Detección e identificación molecular de Pantoea vagans en flores de Dahlia sp.

Dahlias (Dahlia spp.) are flowers native to Mesoamerica and endemic to Mexico. Its consumption as food is an ancient practice, at present there is little health information and regulation for its marketing and consumption. The objective of the study was to identify enteric bacteria associated morphologically, biochemically and molecularly with Dahlia flowers. The results of the morphological characterization revealed the predominance of short Gram-negative bacilli. From the observation of colonial morphology in selective and differential culture media Escherichia coli and Salmonella spp. were identified. However, the use of an automated commercial method classifieds them as Enterobacter cancerogenus. Due to the fact that the two tests used gave different results when identifying the isolated microorganism, the findings were inconclusive. Therefore molecular characterization was used to identify the bacterial isolate. Thus, the predominant bacterium in Dahlia flowers was Pantoea vagans (Access Number CP002206. 1). This is the first report of Pantoea vagans isolated from Dahlia flowers. Las Dalias (Dahlia spp.) son flores nativas de Mesoamérica y endémicas de México. Su consumo como alimento es una práctica antigua, en la actualidad es escasa la información y reglamentación sanitaria para su comercialización y consumo. Al respecto, el objetivo del presente estudio fue identificar morfológica, bioquímica y molecularmente, bacterias de origen entérico asociadas con flores de Dalia. Los resultados de la caracterización morfológica revelaron la predominancia de bacilos cortos Gram negativos. A partir de la observación de la morfología colonial en medios de cultivo selectivos y diferenciales se identificaron como Escherichia coli y Salmonella spp. Sin embargo, el uso de un método comercial automatizado los clasifica como Enterobacter cancerogenus. Debido a que ambas pruebas arrojaron resultados distintos en cuanto a la identidad del microorganismo aislado, no fueron concluyentes. Por lo tanto, se recurrió a la caracterización molecular para la identificación del aislado bacteriano. La bacteria predominante en flores de Dalia, correspondió a Pantoea vagans (Número de acceso CP002206). Éste es el primer reporte de Pantoea vagans aislada de flores de Dalia

Cultivo del coral cuerno de alce Acropora palmata en un sistema recirculado utilizando agua de mar sintética

This study assessed the survival of Acropora palmata fragments under controlled experimental conditions over a period of four months in a recirculating artificial seawater system. The coral fragments (5-9 cm long) were fixed in aragocrete and placed in an aquarium under a photoperiod of 12 h light: 12 h dark, using 150 W lamps (10000 K). The survival rate was 58%. Fragment mortality occurred mostly during the first month, which was associated to the process of bleaching stress as a result of fragmentation. These results showed that the conditioning in captivity of A. palmata using artificial seawater has potential as a viable tool to help the conservation of this species

Methane production by treating vinasses from hydrous ethanol using a modified UASB reactor

<p>Abstract</p> <p>Background</p> <p>A modified laboratory-scale upflow anaerobic sludge blanket (UASB) reactor was used to obtain methane by treating hydrous ethanol vinasse. Vinasses or stillage are waste materials with high organic loads, and a complex composition resulting from the process of alcohol distillation. They must initially be treated with anaerobic processes due to their high organic loads. Vinasses can be considered multipurpose waste for energy recovery and once treated they can be used in agriculture without the risk of polluting soil, underground water or crops. In this sense, treatment of vinasse combines the elimination of organic waste with the formation of methane. Biogas is considered as a promising renewable energy source. The aim of this study was to determine the optimum organic loading rate for operating a modified UASB reactor to treat vinasse generated in the production of hydrous ethanol from sugar cane molasses.</p> <p>Results</p> <p>The study showed that chemical oxygen demand (COD) removal efficiency was 69% at an optimum organic loading rate (OLR) of 17.05 kg COD/m³-day, achieving a methane yield of 0.263 m³/kg COD_added and a biogas methane content of 84%. During this stage, effluent characterization presented lower values than the vinasse, except for potassium, sulfide and ammonia nitrogen. On the other hand, primers used to amplify the 16S-rDNA genes for the domains Archaea and Bacteria showed the presence of microorganisms which favor methane production at the optimum organic loading rate.</p> <p>Conclusions</p> <p>The modified UASB reactor proposed in this study provided a successful treatment of the vinasse obtained from hydrous ethanol production.</p> <p>Methanogen groups (Methanobacteriales and Methanosarcinales) detected by PCR during operational optimum OLR of the modified UASB reactor, favored methane production.</p

Improvement in Methane Production from Pelagic Sargassum Using Combined Pretreatments

The constant golden tides of Sargassum spp., identified to be a mixture of Sargassum natans and Sargassum fluitans, observed recently in the Mexican Caribbean have affected the marine ecosystem and the local economy and have created the need for solutions for their management and use. The Sargassum arrivals have thus been considered as third-generation feedstock for biofuel. Their potential for energetic conversion to biomethane was investigated, with hydrolysis as the limiting step due to its complex composition; therefore, in the present study, different physical, chemical, and enzymatic pretreatments and a combination of them have been evaluated, with the additional use of granular activated carbon, to determine the best yield and methane quality. The combined pretreatments of 2.5% hydrogen peroxide, followed by an enzymatic pretreatment (enzymatic extract from Trametes hirsuta isolated from decomposing wood in the Yucat&aacute;n Peninsula-Mexico), was the best option, reaching a biodegradability of 95% and maximum methane yield of 387 &plusmn; 3.09 L CH4/kg volatile solid. The use of a conductive material, such as granular activated carbon, did not generate significant changes in performance and methane concentration