Antibiotics incorporation in Artemia franciscana nauplii, metanauplii, juveniles and adults, and their inhibitory action on Aeromonas hydrophila bacteria

The crustacean Artemia franciscana has been used as a drug carrier, mainly in its nauplius stage; however, the use of other developmental stages, i.e., metanauplius, juvenile, and adult, potentially allows treating diseases not only in fry but also in juveniles and adults. In the present work, we studied the incorporation of antibiotics in these stages to inhibit the growth of the bacterium Aeromonas hydrophila, which causes a high mortality in freshwater fishes. The antibiotics used were: chloramphenicol (base antibiotic), nitrofurantoin (Macrodantina®, 50 mg capsules) and ciprofloxacin (Ciproflox®, 250 mg capsules). Four wells were made in Petri dishes with Trypticase® soybean agar (TSA) and 2 mL of bacterial inoculum. The wells were used for each antibiotic and one for the control. A 1- mL sample of each Artemia stage, incorporated with an antibiotic, was placed in each well and incubated for 24 h at 37°C, measuring the inhibition halos thereafter. Results indicated that 4 h are needed for the nauplii to become saturated and for the metanauplii, juveniles, and adults to fill their digestive tract with the antibiotic. In nauplii, the three antibiotics produced inhibition halos; in metanauplii, ciprofloxacin produced the best result (22.57 mm); in juveniles, chloramphenicol (38 mm) and ciprofloxacin (33 mm) gave the best results; in adults, the best results were obtained also with chloramphenicol (33 mm) and ciprofloxacin (40 mm). Nitrofurantoin did not yield positive results in metanauplii, juveniles, and adults, and because it is soluble in water, it is recommended to apply it in lipidic solutions to ease its incorporation. Results from this study allow us to establish the bases for the control and treatment of infectious diseases caused by the bacterium Aeromonas hydrophila through the use of commercial antibiotics, easily available in Mexico

Generalización del modelo de compensación binomial de una red de mercadeo multinivel

El marketing multinivel es usado por las empresas para comercializar productos o servicios ofrecidos al público, explotando el círculo social de los individuos que ingresan en estas redes de mercadeo, realizando una venta efectiva y potenciando las ventas de sus productos con poca inversión en publicidad -- En este artículo se analiza el Modelo de Compensación Binario (MCB) del sistema multinivel para implementarlo en cualquier industria y analizar si se puede usar en la comisión de venta de cualquier producto o servicio -- Luego de hallar las series que definen el MCB se desarrollaron, matemáticamente, dichas series y se demostró que el modelo converge, logrando que entregue el valor de comisión máximo por venta que se desea repartir, encontrando que el MCB es financieramente viable para la comercialización de productos o servicios y que además no obedece a un esquema piramidal (Esquema Ponzi)Multilevel Marketing is a way that companies use to market products or services offered to the public, exploiting the social circle of individuals who enter these marketing networks and make an effective sale, boosting the sales of their products with little investment in advertising -- In this document we analyze the Binary Compensation Model of the Multilevel System (MCB) to implement it in any industry of the real sector and analyze if it can be used in the sales commission of any product or service -- After finding the series that define the Binary Compensation Model, those series were developed mathematically and it was demonstrated that the model converges, making it deliver the maximum commission value per sale that it is desired to distribute, finding that the MCB is financially viable for the commercialization of products or services and that also does not obey a pyramid scheme (Ponzi scheme

Estrés laboral, ansiedad y miedo al COVID-19 en médicos generales colombianos

Introduction: Epidemics can cause anxiety in the general population and health professionals. The pandemic caused by the COVID-19 virus is no exception. This study’s objective is to identify symptoms of work-related stress, anxiety and fear of COVID-19 in physicians, as well as to discover their relation with the territorial body in which they work. Methodology: This is a cross-cutting study that explored the symptoms and perceptions of Colombian physicians forced to quarantine, who exercised their profession in March, 2020 during the COVID-19 pandemic. Having provided informed consent anonymously and voluntarily, participants completed a virtual form with general questions on COVID-19. The survey was aimed at finding psychosomatic problems using the Generalized Anxiety Disorder (GAD-7) scale and Fear of COVID-19 (FCV-19S) scale. Participants were classified as working in non-capital or capital municipalities according to the territorial body in which they practiced. Logistic regression between the territorial body (which was taken as an independent variable here) and symptoms of anxiety, work-related stress and fear of COVID-19 (which, in this case, were taken as dependent variables) was performed. Results: Five hundred and thirty-one general physicians participated, with an average age of 30. Seventy-three point three percent practiced in a capital municipality. One third of the surveyed physicians presented mild work-related stress, while 6% presented high or severe work-related stress, without differences between groups (p < 0.05). Symptoms of anxiety were found in 72.9% of the surveyed physicians, more frequently among those who practiced in capitals (p = 0.044). Thirty-seven point one percent presented symptoms of fear of COVID-19 (FCV-19S). No relation was observed in the logistic regression. Discussion: Psychosocial and psychosomatic factors associated with fear are the common denominators of symptoms of anxiety and work-related stress during pandemics. Conclusion: Seven of every ten participants presented symptoms of anxiety or work-related stress, while four presented symptoms of FCV-19S. No relation was observed with the municipalities in which they worked. Introducción. Las epidemias pueden generar angustia en la población general y en los profesionales de la salud, y la pandemia causada por el virus del COVID-19 no es la excepción. El objetivo del presente estudio es determinar la presencia de síntomas de estrés laboral, ansiedad y miedo al COVID-19 en médicos generales, además de estimar la asociación según el ente territorial donde trabajaban. Metodología. Este es un estudio transversal que exploró síntomas y percepciones durante la pandemia del COVID-19 en médicos generales colombianos sometidos a cuarentena obligatoria que ejercieron su profesión en marzo del 2020. Previo consentimiento informado, anónima y voluntariamente, los participantes diligenciaron un formulario virtual con preguntas generales sobre COVID-19. El cuestionario buscaba encontrar problemas psicosomáticos sirviéndose de la Escala para el Trastorno de Ansiedad Generalizada (GAD-7, por sus siglas en inglés) y el FCV-19S (Fear of COVID-19). Los participantes se clasificaron en Municipio no capital o Municipio capital según el ente territorial en donde laboraban. Regresión logística entre el ente territorial (que acá es tomada como variable independiente) con los síntomas de ansiedad, estrés laboral y miedo al COVID-19 (que en este caso es tomado como variable dependiente). Resultados: Participaron 531 médicos generales con edad promedio de 30 años. El 73.3% laboraban en Municipio capital. Un tercio de los encuestados presentó estrés laboral leve, mientras que el 6% presentó estrés laboral alto o severo, esto sin diferencias entre los grupos (p<0.05). Se identificaron síntomas de ansiedad en el 72.9%, más frecuente entre quienes laboraban en las capitales (p=0.044). El 37.1% presentó síntomas de miedo al COVID-19 (FCV-19S). No se observó asociación en la regresión logística realizada. Discusión: Factores psicosociales y psicosomáticos asociados al miedo son el común denominador de los síntomas de ansiedad y estrés laboral en las pandemias. Conclusión: Siete de cada diez participantes presentó síntomas de ansiedad o estrés laboral, mientras que cuatro presentaron síntomas de FCV-19S. No se observó asociación con la clasificación del municipio donde laboraban

Occupational stress, anxiety and fear of COVID-19 in colombian physicians

Introducción. Las epidemias pueden generar angustia en la población general y en los profesionales de la salud, y la pandemia causada por el virus del COVID-19 no es la excepción. El objetivo del presente estudio es determinar la presencia de síntomas de estrés laboral, ansiedad y miedo al COVID-19 en médicos generales, además de estimar la asociación según el ente territorial donde trabajaban. Metodología. Este es un estudio transversal que exploró síntomas y percepciones durante la pandemia del COVID-19 en médicos generales colombianos sometidos a cuarentena obligatoria que ejercieron su profesión en marzo del 2020. Previo consentimiento informado, anónima y voluntariamente, los participantes diligenciaron un formulario virtual con preguntas generales sobre COVID-19. El cuestionario buscaba encontrar problemas psicosomáticos sirviéndose de la Escala para el Trastorno de Ansiedad Generalizada (GAD-7, por sus siglas en inglés) y el FCV-19S (Fear of COVID-19). Los participantes se clasificaron en Municipio no capital o Municipio capital según el ente territorial en donde laboraban. Regresión logística entre el ente territorial (que acá es tomada como variable independiente) con los síntomas de ansiedad, estrés laboral y miedo al COVID-19 (que en este caso es tomado como variable dependiente). Resultados: Participaron 531 médicos generales con edad promedio de 30 años. El 73.3% laboraban en Municipio capital. Un tercio de los encuestados presentó estrés laboral leve, mientras que el 6% presentó estrés laboral alto o severo, esto sin diferencias entre los grupos (p<0.05). Se identificaron síntomas de ansiedad en el 72.9%, más frecuente entre quienes laboraban en las capitales (p=0.044). El 37.1% presentó síntomas de miedo al COVID-19 (FCV-19S). No se observó asociación en la regresión logística realizada. Discusión: Factores psicosociales y psicosomáticos asociados al miedo son el común denominador de los síntomas de ansiedad y estrés laboral en las pandemias. Conclusión: Siete de cada diez participantes presentó síntomas de ansiedad o estrés laboral, mientras que cuatro presentaron síntomas de FCV-19S. No se observó asociación con la clasificación del municipio donde laboraban.Introduction: Epidemics can cause anxiety in the general population and health professionals. The pandemic caused by the COVID-19 virus is no exception. This study’s objective is to identify symptoms of work-related stress, anxiety and fear of COVID-19 in physicians, as well as to discover their relation with the territorial body in which they work. Methodology: This is a cross-cutting study that explored the symptoms and perceptions of Colombian physicians forced to quarantine, who exercised their profession in March, 2020 during the COVID-19 pandemic. Having provided informed consent anonymously and voluntarily, participants completed a virtual form with general questions on COVID-19. The survey was aimed at finding psychosomatic problems using the Generalized Anxiety Disorder (GAD-7) scale and Fear of COVID-19 (FCV-19S) scale. Participants were classified as working in non-capital or capital municipalities according to the territorial body in which they practiced. Logistic regression between the territorial body (which was taken as an independent variable here) and symptoms of anxiety, work-related stress and fear of COVID-19 (which, in this case, were taken as dependent variables) was performed. Results: Five hundred and thirty-one general physicians participated, with an average age of 30. Seventy-three point three percent practiced in a capital municipality. One third of the surveyed physicians presented mild work-related stress, while 6% presented high or severe work-related stress, without differences between groups (p < 0.05). Symptoms of anxiety were found in 72.9% of the surveyed physicians, more frequently among those who practiced in capitals (p = 0.044). Thirty-seven point one percent presented symptoms of fear of COVID-19 (FCV-19S). No relation was observed in the logistic regression. Discussion: Psychosocial and psychosomatic factors associated with fear are the common denominators of symptoms of anxiety and work-related stress during pandemics. Conclusion: Seven of every ten participants presented symptoms of anxiety or work-related stress, while four presented symptoms of FCV-19S. No relation was observed with the municipalities in which they worked

B content and Si/C ratios from cultured diatoms (Thalassiosira pseudonana and Thalassiosira weissflogii): Relationship to seawater pH and diatom carbon acquisition

AbstractDespite the importance of diatoms in regulating climate and the existence of large opal-containing sediments in key air-ocean exchange areas, most geochemical proxy records are based on carbonates. Among them, Boron (B) content and isotopic composition have been widely used to reconstruct pH from foraminifera and coral fossils. We assessed the possibility of a pH/CO2 seawater concentration control on B content in diatom opal to determine whether or not frustule B concentrations could be used as a pH proxy or to clarify algae physiological responses to acidifying pH. We cultured two well-studied diatom species, Thalassiosira pseudonana and Thalassiosira weissflogii at varying pH conditions and determined Si and C quotas. Frustule B content was measured by both laser-ablation inductively coupled mass spectrometry (LA-ICPMS) and secondary ion mass spectrometry (SIMS/ion probe). For both species, frustules grown at higher pH have higher B contents and higher Si requirements per fixed C. If this trend is representative of diatom silicification in a future more acidic ocean, it could contribute to changes in the efficiency of diatom ballasting and C export, as well as changes in the contribution of diatoms relative to other phytoplankton groups in Si-limited regions. If B enters the cell through the same transporter employed for HCO3− uptake, an increased HCO3− requirement with decreasing CO2 concentrations (higher pH), and higher B(OH)4/HCO3− ratios would explain the observed increase in frustule B content with increasing pH. The mechanism of B transport from the site of uptake to the site of silica deposition is unknown, but may occur via silicon transport vesicles, in which B(OH)4− may be imported for B detoxification and/or as part of a pH regulation strategy either though Na-dependent B(OH)4−/Cl− antiport or B(OH)4−/H+ antiport. B deposition in the silica matrix may occur via substitution of a B(OH)4− for a negatively charged SiO− formed during silicification. With the current analytical precision, B content of frustules is unlikely to resolve ocean pH with a precision of paleoceanographic interest. However, if frustule B content was controlled mainly by HCO3− uptake for photosynthesis, which appears to show a threshold behavior, then measurements of B content might reveal the varying importance of active HCO3− acquisition mechanisms of diatoms in the past

The Occurrence of Parthenogenetic Artemia Leach, 1819 (Crustacea: Anostraca) in Cancun Saltern, Mexico

Artemia, commonly known as brine shrimp, constitutes a globally distributed halophilic zooplankton organism, occupying hypersaline environments including inland lakes, salterns, and coastal salt lagoons. The genus Artemia encompasses regional endemic species and a diverse array of parthenogenetic lineages, which are characterized by various ploidy levels and distributed across Asia, Europe, Africa, and Australia. The aim of the study is to investigate and determine the taxonomic status of an unusual mitochondrial cytochrome oxidase subunit I (mtCOI) sequence among 14 different populations of Artemia franciscana Kellogg, 1906, collected from Cancun saltern in Mexico. DNA extraction and mtCOI gene amplification were conducted and taxonomic classification was achieved via BLAST analysis. A phylogenetic tree, constructed using Maximum Likelihood methodology, revealed the phylogenetic relationship between Mexican parthenogenetic Artemia and other parthenogenetic lineages of varying ploidy levels. The results unequivocally confirm the presence of parthenogenetic Artemia in Cancun saltern, aligning with sequences from Asia and Europe. Phylogenetic analysis positions revealed the Mexican specimens within the clade of diploid parthenogenetic lineages. The competitive vigor and reproductive capabilities of A. franciscana appear to have limited the expansion of parthenogenetic Artemia in North America. Further research endeavors are essential to unravel the enigmatic biogeography of parthenogenetic Artemia in North America and shed light on its potential native or introduced status

Crecimiento y actividad de las enzimas digestivas de la trucha arcoíris (Oncorhynchus mykiss) alimentadas con probióticos autóctonos

Background. Probiotics in aquaculture are becoming important to improve the growth of fish, because of some useful modifications of physiological process, and consequently in fish growth.Goals.To assess the effects of two autochthonous bacterial strains, with probiotics features, on rainbow trout growth and digestive enzyme activities. Methods. In this study, was tested the effect of Bacillus pumilus (BP), Bacillus sp. (BSP) and the mixture (BPSP), on the growth and the activity of digestive enzymes of rainbow trout. The autochthonous strains, previously characterized as potentials probiotics in vitro, were administered individually at 1 x 107CFU g-1food, and as a mixture, the cellular concentration 0.5 x 107CFU g-1 food each one; during eight weeks. Results. Neither of the strains used generated significative growth, compared to the control. Were the fish fed with BSP that had the best growth, respect to BP and BPSP. The highest activity of enzymes was obtained in the fish treated with bacteria, and only in the case of BPSP the fish had a significant increase (P < 0.05) of proteases and amylase activity, compared with CTRL. Under the current trial conditions, strains BP and BSP, had no positive effects on growth and enzyme activities. The mixture improved the activity of protease and amylase of rainbow trout.Antecedentes: Los probioticos en la acuicultura han ganado importancia, ya que pueden mejorar la salud de los peces debido a los efectos positivos en la fisiologia digestiva de los animales y, consecuentemente, en el crecimiento. Objetivos: Evaluar el efecto de dos cepas bacterianas autoctonas con potencial probiótico sobre el crecimiento y la actividad de las proteasas totales, lipasa y amilasa de la trucha arcoiris. Métodos: Se evaluo el efecto de Bacillus pumilus (BP), Bacillus sp. (BSP) y la mezcla (BPSP) en el crecimiento y la actividad de enzimas digestivas de la trucha arcoiris. Las cepas autoctonas, previamente caracterizadas como potenciales probioticos in vitro, fueron suministradas a los peces a una densidad celular de 1x107 UFC g-1de alimento, individualmente y la mezcla, a la mitad de la concentracion cada una; durante ocho semanas. Resultados: Ninguna de las cepas empleadas genero crecimiento significativo, comparado con el control. Sin embargo, los peces alimentados con BSP tuvieron mejor crecimiento, respecto de BP y BPSP. La actividad enzimatica (proteasas, lipasa y amilasa) mas alta se obtuvo en los peces alimentados con BPSP, y fueron estadísticamente diferentes (P< 0.05) del control. Conclusiones: Las condiciones de experimentacion evaluadas no generaron efecto significativo sobre el crecimiento y la actividad de las enzimas digestivas cuando las cepas se suministraron individualmente. El consorcio bacteriano incremento significativamente la actividad de los tres grupos enzimaticos de la trucha arcoiris

Modelo de orientación vocacional para instituciones educativas en Colombia /

Este libro contiene los resultados del proyecto “Movilizando la Educación Superior en el Departamento del Atlántico”, financiado por el Ministerio de Educación Nacional de Colombia, con el fin abordar, como caso de estudio, la demanda, la oferta y las estrategias de fortalecimiento del capital humano en este departamento del Caribe colombiano. El propósito final de la investigación fue configurar una propuesta de Modelo de Orientación Vocacional que ayude al proceso de acompañamiento de selección de programas formativos en los niveles técnico y tecnológico de los estudiantes de media vocacional en el país, de acuerdo con las necesidades que existen en sectores productivos estratégicos previamente identificadosEditorial Universidad del Nort

Formulación de licor producido con arándanos (Vaccinium corymbosum L.) Huacho-2021

Objective: To determine the appropriate formulation to produce liquor from blueberries (Vaccinium corymbosum L.) taking into account the dilution, amount of sugar and fermentation time. Materials and methods: Several batches of fermentation were used, for dilution 20%, 30% and 40% of water were used based on the weight of the blueberry pulp. For the appropriate amount of sugar, it is recommended to work with 21ºBrix so that the viniferous yeasts act optimally. In the investigation, the initial ºBrix of the blueberry ranged between 10,08º and 10,12º; which we take up to 21º Brix to be able to obtain up to 12,5% alcohol; An Excel program was used, which when entering initial parameters such as blueberry pulp mass, initial ºBrix, density, pH and acidity; the amount of sugar to add was obtained or the ratio that 1g of sugar raises 0.1ºBrix in 1 liter of water, wine or must. For the fermentation time, it was decided to obtain a blueberry liqueur, with approximately 12% or 12º of alcohol. Results: for the dilution, it was found that the adequate relation between the weight of the blueberry and the water is 20%, better color and aroma of the liquor were obtained. The amount of sugar to add, with an initial 10,08 ºBrix, resulted in 478g. The time required to obtain 12ºBrix, at a fermentation temperature of 24,3ºC, was 7 days. Conclusion: It has been possible to find the appropriate formulation to produce cranberry liqueur. For the dilution it was 20% for better color and aroma. For sugar, it was possible to find the amount to add to the cranberry juice to reach an initial 21ºBrix of the must. Seven (7) days of fermentation were used to obtain a liquor with 12% alcohol, as a minimum alcoholic content.Objetivo: Determinar la formulación adecuada para producir licor a partir del arándano (Vaccinium corymbosum L.) tomando en cuenta la dilución, cantidad de azúcar y tiempo de fermentación. Materiales y métodos: Se trabajaron con varios lotes de fermentación, para la dilución se trabajó con 20%, 30% y 40% de agua tomando como base al peso de la pulpa del arándano. Para la cantidad de azúcar apropiada se recomienda trabajar con 21ºBrix para que las levaduras viníferas actúen de manera óptima, en la investigación los ºBrix iniciales del arándano oscilaron entre 10,08º y 10,12º; los cuales llevamos hasta 21 ºBrix para poder obtener hasta 12,5% de alcohol; se utilizó un programa en Excel, que al ingresarle parámetros iniciales como masa de pulpa de arándano, ºBrix inicial, densidad, pH y acidez; se obtuvo la cantidad de azúcar a agregar o la relación que 1g de azúcar eleva 0,1 ºBrix en 1 litro de agua, vino o mosto. Para el tiempo de fermentación se decidió obtener un licor de arándano, con un 12% o 12º de alcohol aproximadamente. Resultados: para la dilución, se encontró que la relación adecuada entre el peso del arándano y el agua es del 20%, se obtuvo mejor color y aroma del licor. La cantidad de azúcar a agregar, con un 10,08 ºBrix iniciales resultaron 478g. El tiempo necesario para obtener los 12ºBrix, a una fermentación con 24,3ºC de temperatura resultó 7 días. Conclusión: Se ha logrado encontrar la formulación adecuada para producir licor de arándano. Para la dilución fue del 20% por mejor color y aroma. Para el azúcar se logró encontrar la cantidad a agregar al jugo de arándano para llegar a 21ºBrix iniciales del mosto. Se emplearon siete (7) días de fermentación para llegar a obtener un licor con 12% de alcohol, como contenido mínimo alcohólico

Reflexiones universitarias. San Pedro Valencia: renovación urbana, saneamiento ambiental y emprendimientos turísticos. Otoño 2015

Los trabajos que aquí se presentan se elaboraron por las y los estudiantes como parte de las actividades del Proyecto de Aplicación Profesional (PAP) “San Pedro Valencia: renovación urbana, saneamiento ambiental y emprendimientos turísticos”, durante el periodo de Otoño de 2015. A lo largo del periodo los autores compartieron sus reflexiones en torno a su percepción sobre el contexto en el que actúa el PAP; sobre las alternativas posibles a la problemática detectada y lo que significa pensar una alternativa; sobre los sujetos con los que se ha interactuado a lo largo de la experiencia de trabajo y sobre el papel del profesionista y del ciudadano en un mundo como el que nos tocó vivir. La obra está compuesta por reflexiones personales de las y los estudiantes que, explorando estas temáticas, comparten sus aprendizajes y observaciones de forma vívida.ITESO, A.C