Resumo A relação entre a identidade profissional e a prática docente dos professores rurais é fundamental para encontrar respostas a respeito do ser, do fazer - das condições em que é feito - e do que deve ser o professor no contexto rural. Este artigo de pesquisa descreve alguns elementos de autopercepção, formação e experiência de ensino que identificam professores rurais de duas instituições de ensino rural no leste de Antioquia que trabalham em áreas semirrurais, rurais e rurais remotas. O estudo foi conduzido a partir da abordagem narrativa biográfica com diferentes técnicas de pesquisa, tais como o seminário, o grupo de discussão, o relato autobiográfico, o jogo dramático e o metaplano. A análise dos dados permitiu a identificação de elementos comuns nas trajetórias individuais e coletivas, e revelou tensões, desafios, interesses e necessidades de treinamento dos professores participantes. Além disso, tornou evidente a necessidade de uma rede de professores rurais na Antioquia oriental, para gerar processos de comunicação, pesquisa, treinamento e organização destes atores vitais na educação rural.

Resumen La relación entre la identidad profesional y el ejercicio de la docencia del maestro rural es fundamental para encontrar respuestas frente al ser, el hacer -las condiciones en que se hace- y el deber ser del maestro en contextos rurales. Este artículo de investigación da cuenta de algunos elementos de autopercepción, formación y experiencia docente que identifican a maestros rurales de dos instituciones educativas rurales del Oriente Antioqueño que se desempeñan en zonas semirrurales, rurales y rurales alejadas. El estudio se desarrolló desde el enfoque biográfico narrativo con diversas técnicas de investigación como el seminario taller, el grupo de discusión, el relato autobiográfico, el juego dramático y el metaplan. El análisis de los datos permitió la identificación de elementos comunes en los trayectos individuales y colectivos, y develar tensiones, retos, intereses y necesidades de formación de los maestros participantes. Además, hizo evidente la necesidad de una red de maestros rurales en el Oriente Antioqueño, que permita generar procesos de comunicación, investigación, formación y organización de estos actores vitales en la educación rural.

Abstract The relationship between professional identity and the teaching practice of the rural teachers is fundamental to find answers regarding the being, the doing-the conditions in which it is done-and what the teacher should be in rural contexts. This research article describes some elements of self-perception, training, and teaching experience that identify rural teachers from two rural educational institutions in eastern Antioquia that work in semi-rural, rural, and remote rural areas. The study was conducted from the narrative biographical approach with different research techniques such as the seminar workshop, the discussion group, the autobiographical account, the dramatic play, and the metaplan. The analysis of the data allowed the identification of common elements in the individual and collective trajectories, and revealed tensions, challenges, interests, and training needs of the participating teachers. In addition, it made evident the need for a network of rural teachers in eastern Antioquia, to generate processes of communication, research, training, and organization of these vital actors in rural education.

Resumo Objetivo: Avaliar a dinâmica do fluxo do líquido cerebrospinal por cine-ressonância magnética com contraste de fase em crianças saudáveis, para determinar os valores normais de fluxo nesta população, bem como a diferença entre medições distintas de acordo com idade, sexo ou área da superfície corporal. Materiais e Métodos: Convocamos 32 crianças saudáveis em uma análise descritiva de prevalência para a avaliação quantitativa do fluxo do líquido cerebrospinal pelo aqueduto de Sylvius. A análise foi realizada por meio de software especializado, desenhando uma região de interesse no aqueduto. Uma curva de fluxo-tempo e medições automáticas de diversos parâmetros foram obtidas. Resultados: Os seguintes valores normais foram obtidos: fluxo efetivo de 1,10 ± 0,99 mL/m; volume médio de 12,2 ± 10,1 μL/ciclo; velocidade média de 0,72 ± 1,00 cm/s; pico de velocidade sistólica de 5,28 ± 2,30 cm/s; pico de velocidade diastólica de 4,51 ± 1,77 cm/s. Esses valores não foram afetados pela idade ou sexo das crianças. Além disso, não foi encontrada correlação significativa entre a área corporal, a velocidade média e o volume sistólico. Conclusão: De modo geral, os parâmetros básicos do fluxo do líquido cerebrospinal independem de idade e sexo em crianças.

Abstract Objective: To evaluate cerebrospinal fluid dynamics, using cine phase-contrast magnetic resonance imaging (cine-PC MRI), in healthy pediatric subjects, determining the normal flow values in this population, as well as identifying differences related to age, sex, and body surface area. Materials and Methods: This was a descriptive cross-sectional study involving 32 healthy children and adolescents, in whom the flow of cerebrospinal fluid through the cerebral aqueduct was evaluated quantitatively with cine-PC MRI. We used specialized software to analyze the images obtained with cine-PC MRI, drawing a region of interest on the aqueduct. A flow-time curve was obtained, as were automated measurements of the various parameters. Results: The following normal (mean) values were obtained: net flow, 1.10 ± 0.99 mL/m; stroke volume, 12.2 ± 10.1 μL/cycle; mean velocity, 0.72 ± 1.00 cm/s; peak systolic velocity, 5.28 ± 2.30 cm/s; peak diastolic velocity, 4.51 ± 1.77 cm/s. These values were not affected by age or sex. In addition, body surface area was not found to correlate significantly with mean velocity or stroke volume. Conclusion: In children and adolescents, the basic cerebrospinal fluid flow parameters, as determined by cine-PC MRI, appear to be independent of age and sex.

Abstract Essential oils are products from aromatic plants, which, due to their biological, allelopathic, antioxidant and antimicrobial effects, are important for food preservation. Kajikia audax is a fish of great commercial importance, however, it is highly perishable, requiring strategies to extend its shelf life. In vitro antimicrobial activity of Bursera graveolens essential oil was determined against microorganisms isolated from K. audax. Essential oil was extracted by steam distillation, obtaining a yield of 1.25%, a density of 0.83 g/ml and a refractive index of 1.473°, in addition, it was determined by GC-MS that D-limonene (77.6%) is the majority compound. Antimicrobial tests showed that the minimum inhibitory concentration (MIC) for Aeromonas salmonicida and Pichia kudriavzevii was 1.62 mg/ml and 6.48 mg/ml respectively, and the minimum bactericidal concentration (MBC) was 25.92 mg/ml for both microorganisms. Pseudomonas aeruginosa showed total resistance against the concentrations used. B. graveolens essential oil turned out to be a potential product to control the growth of microorganisms isolated from K. audax, however, it should be tested against species of the genera Vibrio, Flavobacterium, Shewanella, Lactococcus and Streptococcus that cause spoiling of hydrobiological products.

Objective: Current treatment for borderline personality disorder (BPD) involves psychological and pharmacological interventions. However, neuromodulation techniques such as repetitive transcranial magnetic stimulation (rTMS) may positively affect BPD symptomatology. The objective of this study was to evaluate the clinical and neuropsychological effects of rTMS on the dorsomedial prefrontal cortex (DMPFC) in BPD patients. Methods: Fourteen patients with BPD were randomized into two groups (active vs. sham) for 15 sessions of rTMS on the DMPFC. Clinical effects were measured using the Borderline Symptoms List (BSL), Clinical Global Impression Scale for BPD (CGI-BPD), Borderline Evaluation of Severity over Time (BEST), Hamilton Depression Rating Scale (HDRS), Hamilton Anxiety Rating Scale (HARS), and Barratt’s Impulsiveness Scale (BIS). Neuropsychological effects were determined by a Stop-Signal Task (SST), the Wisconsin Card-Sorting Test (WCST), and the Iowa Gambling Test (IGT). Results: Within-group comparison showed significant differences (p < 0.05) in CGI-BPD (total score and six of nine psychopathologic domains), BEST, HDRS, HARS, and IGT scores for active modality. Conclusion: The 5 Hz-DMPFC rTMS technique was well tolerated and lessened the severity of BPD symptomatology, especially abandonment, affective issues, interpersonal relationships, suicidal behavior, anger, and paranoid ideation. Cognitive improvement was seen in decision-making. Additional studies are needed to fully evaluate the effects of rTMS on BPD symptomatology. Clinical Trial Registration: NCT03832777.

Resumen Este trabajo tiene como objetivo estudiar empíricamente las opciones reales como una técnica para la valuación financiera de proyectos de inversión cafetaleros de base tecnológica, además de realiza una comparación de la técnica tradicional con la técnica de opciones reales para dicha valuación. Para cumplir con el objetivo planteado se aplicó la técnica de opciones reales a cuatro proyectos de inversión de base tecnológica del sector cafetalero, cabe mencionar que dichos proyectos de inversión cuentan con flujos de efectivo correspondientes a diez años cada uno. Se utilizó la técnica de opciones reales, aplicado específicamente el modelo desarrollado por los autores Black & Scholes. El análisis que se realizó en la presente investigación está limitado a proyectos de inversión cafetaleros, los cuales fueron obtenidos de la Secretaría de Agricultura y Desarrollo Rural (SADER). La originalidad de la presente investigación radica en que en México no se tiende a utilizar esta metodología, sino que, por cuestiones de facilidad, se utilizan las técnicas tradicionales que consiste en valor presente neto, tasa interna de retorno y periodo de recuperación. Con la aplicación de la metodología de opciones reales se obtuvo un valor superior al que se obtuvo al aplicar la técnica tradicional, por lo cual se puede decir que las opciones reales favorecen a reducir el riesgo y la incertidumbre en los proyectos para una mejor evaluación de estos. Por lo tanto, se recomienda la utilización de opciones reales, ya que esta técnica da una mayor certeza de los resultados de la técnica tradicional. Código JEL: E37, M21, O22

Abstract This work aims is real options empirically study as a technique for technology-based coffee investment projects financial valuation, in addition to comparing the traditional valuation projects techniques versus the real options technique. In order to get the goal of this work the real options technique was applied to four technology-based investment projects from the coffee sector, it is most be mentioning that the four investment projects have cash flows corresponding to ten years each one. The real options technique was use, specifically applying the model developed by the authors Black & Scholes. The analysis carried out in this investigation is limited to coffee investment projects, which were obtained from the Ministry of Agriculture and Rural Development in Mexico (SADER). Present investigation originality is that in Mexico real option methodology does not tend to be used as a rule, but for reasons of ease, traditional techniques are used, consisting of net present value, internal rate of return and recovery period. With the application of the real options methodology, a higher value was obtain than that obtained by applying the traditional technique, so it can be said that the real options favor reducing risk and uncertainty in projects for a better evaluation of these. Therefore, the use of real options is highly recommended, since real options technique gives greater certainty of the results of the traditional technique. Código JEL: E37, M21, O22

Abstract: Gastric teratomas are usually benign. The case of a two-month-old male patient in whom an abdominal mass was detected is presented. Ultrasound and CT studies of the abdomen showed a large tumor in the greater curvature of the stomach. By endoscopy, intra-gastric growth was observed. The treatment was surgical, with gastrectomy and total tumor resection. By pathology, the diagnosis was of mature gastric teratoma. Monitoring for five years has not revealed evidence of recurrence or malignancy.

Resumen: El teratoma gástrico es usualmente benigno. Se presenta el caso de un paciente masculino de dos meses edad en quien se detectó una masa abdominal. Los estudios de ultrasonido y TAC de abdomen demostraron un tumor grande en la curvatura mayor del estómago; por endoscopía se observó crecimiento intragástrico en la región del cardias. El tratamiento fue quirúrgico, con gastrectomía y resección total de la tumoración. El diagnóstico de patología fue de teratoma maduro gástrico. El seguimiento por cinco años no ha revelado datos de recidiva ni malignidad.

Abstract The present work constitutes a diagnostic approach in its initial phase of six basic aspects of the school trajectory (ST) of the students of the Degree in Graphic Design of the University of Sonora, prior to the development of intervention actions. The concept of ST is an instrument to describe and understand the student's transit: from admission and graduation, within higher education institutions. However, these results of quantitative research must be recontextualized and put at the service of the educational intervention for the improvement of the TE described. The objective is to start from these indicators to raise the set of factors and conditions that explain and serve as a direct reference in the school trajectory and professional training of students. The analyzed data are from the 2009 cohorts to date concerning: retention of the first to the second year of the race; subjects of greater reprobation, as much of the common institutional axis as of the rest of the curriculum; accreditation of the Social Service, Professional Practices and Culture and Sports Activities; late discharge and late titration. A group of measures is proposed with the collaborative teaching planning of the program, oriented to the improvement of the TE of the students of the Degree in Graphic Design of the University of Sonora.

Resumen El presente trabajo constituye un acercamiento diagnóstico en su fase inicial de seis aspectos básicos de la trayectoria escolar (TE) de los estudiantes de la Licenciatura en Diseño Gráfico de la Universidad de Sonora, previo al desarrollo de acciones de intervención. El concepto de TE es un instrumento para describir y comprender el tránsito del estudiante: desde el ingreso, el egreso y la titulación, dentro de las instituciones de educación superior. Sin embargo, estos resultados de la investigación cuantitativa deben ser recontextualizados y puestos al servicio de la intervención educativa para la mejora de las TE descritas. El objetivo es, partir de estos indicadores para plantear el conjunto de factores y condicionantes que expliquen y sirvan de referencia directa en la trayectoria escolar y la capacitación profesional de los estudiantes. Los datos analizados son de las cohortes del año 2009 hasta la fecha concernientes a: retención del primero al segundo año de la carrera; materias de mayor reprobación, tanto del eje común institucional como del resto del plan de estudios; acreditación del Servicio Social, Prácticas Profesionales y Actividades de Cultura y Deportes; egreso tardío y titulación tardía. Se propone un conjunto de medidas con la planeación colaborativa docente del programa, orientada a la mejora de las TE de los estudiantes de la Licenciatura en Diseño Gráfico de la Universidad de Sonora.

Biochar samples were produced using three types of residual biomass: corncob, coffee husk and shrimp exoskeleton to measure their effect at different doses on germination and growth of seeds of the forest specie Capparis scabrida in vivarium conditions. A comprehensive characterization of produced biochar was carried out including textural, morphological, structural and surface chemical analyzes. Viable seeds of the forestry specie were placed on substrates with doses of 0, 15 and 30% of three types of biochar and placed in 2 kg bags in a vivarium. Finally, the germination and growth of Capparis scabrida in vivarium conditions were not influenced by the dose and type of biochar used. Germination parameter such as time and % of germination were evaluated; while to evaluated seedling growth, stem and root growth, stem thickening, root mass and aerial part increases and microbial load over the root were assessed. It was determined that the type of biochar had an influence only on the germination time and the biochar dose had an influence on the increase of aerial part mass during the growth of the seedlings. The rest of parameters evaluated not affected either by the type or by the biochar dose

Se produjeron biocarbones a partir de tres tipos de biomasa residual: coronta de maíz, cáscara de café y exoesqueleto de langostino, para estudiar la influencia de diferentes dosis de los mismos en la germinación y crecimiento en vivero de semillas de la e specie forestal Capparis scabrida (Sapote). Se realizó una exhaustiva caracterización de los biocarbones obtenidos en base a sus propiedades texturales, morfológicas, estructurales y química superficial. Semillas viables de sapote fueron colocadas en sustratos con dosis de 0, 15 y 30 %wt de cada uno de los tres tipos de biocarbones obtenidos y se colocaron en bolsas de 2 kg en condiciones de vivero. Se evaluaron los parámetros de germinación: tiempo y % de germinación; y de crecimiento de las plántulas: cre cimiento de raíz y tallo, engrosamiento de tallo, incremento de masa de raíz y parte aérea y la carga microbiana en la raíz. Se determinó que el tipo de biocarbón tuvo influencia solamente en el tiempo de germinación y la dosis de biocarbón tuvo influencia en el incremento de masa de parte aérea durante el crecimiento de las plántulas. El resto de parámetros evaluados no fueron afectados ni por el tipo ni por la dosis de biocarbón

Resumen Se caracterizaron y se evaluaron carbones activados comerciales (A, B, C y D) utilizados en filtros para el tratamiento de agua en la descontaminación de metales pesados presentes en agua de río y en la eliminacion de microorganismos coliformes; los carbones comerciales resultaron tener estructuras microporosas y mesoporosas. Se determinaron areas superficiales entre 705 y 906 m2/g. Los carbones fueron amorfos y se detectó la presencia de agentes antibacterianos, tales como Ag, Cl, Cu y Si. Se determinó que para el As y Pb, cuyas concentraciones iniciales en el agua contaminada (agua del Río Tumbes-Perú) fueron 56,7 y 224,0 μg/L, respectivamente, el porcentaje de adsorción fue cercano al 100%. También se encontró que la relación entre el pH de carga cero de los carbones y pH del agua del río durante los experimentos juega un rol determinante en la adsorción de los elementos analizados. Por otro lado, la capacidad antibacteriana fue evaluada satisfactoriamente frente a las siguientes cepas de bacterias gram negativas fecales: Escherichia coli (ATCC® 25922™), Salmonella typhimurium (ATCC® 14028™) y Shigella flexneri (ATCC® 12022™). Esta capacidad se basa en la presencia superficial en los carbones de los agentes antibacterianos mencionados.

Abstract Comercial activated carbon samples (A, B, C, and D) used in filters for the treatment of water were characterized and evaluated in the decontamination of heavy metals present in river water and in the elimination of coliform microorganisms. The carbon samples had microporous and mesoporous structures. Surface areas of between 705 and 906 m2/g were found. The carbon samples were amorphous and the presence of antibacterial agents such as Ag, Cl, Cu, and Si was detected. It was determined that for As and Pb, whose initial concentrations in contaminated water (water of the Tumbes river-Peru) were 56.7 and 224.0 μg/L, respectively, the percentage of adsorption was close to 100%. The relationship between point of zero charge pH of the activated carbons and pH of the river water during the experiments plays a determinant role in the adsorption of the analyzed elements. The antibacterial capacity was evaluated satisfactorily against the following strains of fecal gram negative bacteria: Escherichia coli (ATCC® 25922™), Salmonella typhimurium (ATCC® 14028™), and Shigella flexneri (ATCC® 12022™). This ability is based on the surface presence in the carbons ofthe mentioned antibacterial agents.

Resumo Carvões ativados comerciais (A, B, C e D) usado em filtros para o tratamento de água foram caracterizados e avaliados na descontaminação de metais pesados da água do rio e para a remoção de microrganismos coliformes. Os carvões comerciais mostraram estruturas microporosas e mesoporosas. Foram determinadas as áreas superficiais entre 705 e 906 m2/g. As amostras de carvão foram amorfas e foi detectada a presença de agentes antibacterianos, tais como Ag, Cl, Cu e Si. Determinou-se que, no caso de As e Pb, cujas concentrações iniciais na água contaminada (água do rio Tumbes-Peru) foram de 56,7 e 224,0 μg/L respectivamente, a taxa de adsorção foi de quase 100%. Também foi econtrado que e a relação entre o pH de carga zero dos carvões e o pH da água do rio durante as experiências desempenha um papel decisivo na adsorção dos elementos analisados. Além disso, a capacidade antibacteriana foi avaliada com sucesso contra as seguintes variedades de bactérias gram negativas de origem fecal: Escherichia coli (ATCC® 25922™), Salmonella typhimurium (ATCC® 14028™) e Shigella flexneri (ATCC® 12022™). Esta capacidade esta baseada na presença de agentes bacterianos na superfície dos carvões.

Synthesis of TiO2 particles was made by sol-gel technique assisted of ultrasonic radiation from an alcoholic solution of titanium isopropoxide. Then was subjected to a heat treatment in air at 350 °C for 1 h. X-ray diffraction and transmission electron microscopy confirmed that the size of the crystalline domains is between 10 and 37 nm. Infrared spectroscopy study confirms the presence of -OH groups on the surface of TiO2. Modification of the morphology and surface area, due to the influence of exposure time to the ultrasonic radiation, is evidenced by studies of SEM and BET respectively. Properties of TiO2 obtained were studied by monitoring the degradation of solutions of methyl orange in the presence of UV-A radiation. It was observed that larger the ultrasonic radiation exposure during the TiO2 synthesis larger the constant velocity for the photocatalytic reaction for the methyl orange.

La síntesis de las partículas de TiO2 se realizó mediante la técnica sol-gel asistida con radiación ultrasónica a partir de una solución alcohólica de isopropóxido de titanio. Luego se sometió a un tratamiento térmico en atmósfera de aire a 350 ºC por 1 h. Difracción de rayos X y microscopía electrónica de transmisión confirmaron que el tamaño de los dominios cristalinos se encuentran entre 10 y 37 nm. El estudio de espectroscopía infrarroja confirma la presencia de grupos -OH en la superficie del TiO2. La modificación de la morfología y el área superficial, debido a la influencia del tiempo de exposición a la radiación ultrasónica, se evidencia con los estudios de microscopía electrónica de barrido y BET, respectivamente. Las propiedades del TiO2 obtenido se estudiaron monitoreando la degradación de soluciones de anaranjado de metilo en presencia de radiación UV-A. Se observó que a mayor exposición de radiación ultrasónica durante la síntesis de las muestras de TiO2, mayor fue la constante de velocidad para la reacción de fotocatálisis del anaranjado de metilo.

El objetivo principal de esta investigación es comparar las metodologías de Box y Jenkins: Modelo ARIMA y Modelo de Función de Transferencia (MFT), utilizadas frecuentemente en estadística para predicción con series de tiempo, con la técnica de la Inteligencia Artificial denominada Redes Neuronales Artificiales (RNA). Se proponen metodologías para predicción con una red neuronal artificial utilizando el algoritmo de retropropagación y las neuronas neo-difusas. El comportamiento de los métodos se analiza mediante casos de estudio y haciendo uso de criterios comparativos para las fases de ajuste y predicción.

This paper deals with a comparison between Box and Jenkins methodologies and Artificial Neural Networks on time series forecasting. ARIMA and Transfer Function Models are compared with Neural Network Models. Performance of the building models are analysed using comparative criteria during the prediction and fitness stage.