Resistance induction with silicon in Hass avocado plants inoculated with Phytophthora cinnamomi Rands.

Root rot caused by Phytophthora cinnamomi Rands, is one of the main factors that limits avocado production worldwide; silicon as a defense inducer seems to be a viable strategy to integrate into the management of this disease. Hereby, the present study evaluated the induction of resistance with silicon in Hass avocado plants inoculated with P. cinnamomi, as a possible alternative to conventional agrochemical management. A potassium silicate solution (10 mL, 0.2 M expressed as SiO2) was applied by irrigation, for ten days before inoculation with P. cinnamomi in Hass avocado plants. Leaf samples were taken at 3, 24, 144, and 312 h after inoculation with the pathogen. Peroxidase (POD) and polyphenol oxidase (PPO) enzymes had their highest activity 3 h after pathogen inoculation (p < .05). There was a decrease in the activity of the enzyme phenylalanine ammonialyase (PAL), in the content of total phenols, and the inhibition capacity of the DPPH● radical, between 3 h and 24 h in the plants with the inducer and inoculated with P. cinnamomi (p < .05). The results suggest a beneficial effect of silicon as a defense inducer in Hass avocado plants, manifested in the activation of enzymatic pathways related to the regulation of oxidative stress and the synthesis of structural components. Therefore, the application of silicon as a defense inducer emerges as a strategy to include in the integrated management of the disease caused by P. cinnamomi in Hass avocado.

Introducing Lipophilicity to (Polyhydroxyalkyl)thiazolidine Carboxylic Acids Via Acylation.

The therapeutic efficacy of bioactive compounds is related to their bioavailability. In turn, the bioavailability depends on the equilibrium between the hydrophilicity and the lipophilicity. 2(R,S)-(Polyhydroxyalkyl)thiazolidine-4(R) carboxylic acids (TCAs), obtained from the condensation of l-cysteine and an aldose, have been recognized as nontoxic precursors of glutathione with important preventive and therapeutic effects. The bioavailability of these compounds can be improved by enhancing their lipophilicity. This can be achieved by the introduction of some acyl groups derived from fatty acids via esterification of the aldose hydroxyl groups. With this purpose four new compounds were synthesized through a selective palmitoyl acylation of d-(-)-ribose and d-(+)-glucose and subsequent condensation with l-cysteine. In addition, the log P of the new compounds was calculated as a measure of the lipophilicity, and in vitro 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) tests were performed as a measure of the antioxidant capability.

Oligosaccharides: Defense Inducers, Their Recognition in Plants, Commercial Uses and Perspectives.

Plants have innate immune systems or defense mechanisms that respond to the attack of pathogenic microorganisms. Unlike mammals, they lack mobile defense cells, so defense processes depend on autonomous cellular events with a broad repertoire of recognition to detect pathogens, which compensates for the lack of an adaptive immune system. These defense mechanisms remain inactive or latent until they are activated after exposure or contact with inducing agents, or after the application of the inductor; they remain inactive only until they are affected by a pathogen or challenged by an elicitor from the same. Resistance induction represents a focus of interest, as it promotes the activation of plant defense mechanisms, reducing the use of chemical synthesis pesticides, an alternative that has even led to the generation of new commercial products with high efficiency, stability and lower environmental impact, which increase productivity by reducing not only losses but also increasing plant growth. Considering the above, the objective of this review is to address the issue of resistance induction with a focus on the potential of the use of oligosaccharides in agriculture, how they are recognized by plants, how they can be used for commercial products and perspectives.

Rice-Associated Rhizobacteria as a Source of Secondary Metabolites against Burkholderia glumae.

Various diseases, including bacterial panicle blight (BPB) and sheath rot, threaten rice production. It has been established that Burkholderia glumae (B. glumae) is the causative agent of the above mentioned pathologies. In the present study, antagonistic activity, growth promotion, and the metabolite profiles of two rhizobacteria, isolated in different paddy fields, were assessed against B. glumae. Strains were identified based on 16S rRNA gene sequences, and the phylogenetic analyses showed that both strains belong to the genus Enterobacter, with high similarity to the strain Enterobacter tabaci NR146667.2 (99%). The antagonistic activity was assessed with the disc diffusion method. Active fractions were isolated through a liquid/liquid extraction with ethyl acetate (EtOAc) from the fermentation media, and their antibacterial activities were evaluated following the Clinical and Laboratory Standards Institute (CLSI) guidelines. The Pikovskaya modified medium was used to test the ability of in vitro inorganic phosphorus solubilization, and BSB1 proved to be the best inorganic phosphorus solubilizer, with a solubilization index (SI) of 4.5 ± 0.2. The glass-column fractionation of the EtOAc extracted from BCB11 produced an active fraction (25.9 mg) that inhibited the growth of five B. glumae strains by 85-95%. Further, metabolomic analysis, based on GC-MS, showed 3-phenylpropanoic acid (3-PPA) to be the main compound both in this fraction (46.7%), and in the BSB1 extract (28.6%). This compound showed antibacterial activity against all five strains of B. glumae with a minimum inhibitory concentration (MIC) of 1000 mg/L towards all of them. The results showed that rice rhizosphere microorganisms are a source of compounds that inhibit B. glumae growth and are promising plant growth promoters (PGP).

Aplicabilidad clínica de software diagnóstico de la dinámica cardíaca basado en la Ley de Zipf-Mandelbrot / Clinical applicability of the diagnostic software of cardiac dynamics based on the Zipf-Mandelbrot law

RESUMEN Introducción: La Ley de Zipf-Mandelbrot permitió el desarrollo de una metodología que realiza distinciones cuantitativas entre dinámicas cardíacas agudas y normales, de forma objetiva y reproducible. Objetivo: Confirmar la capacidad diagnóstica y utilidad clínica de un software que automatiza una metodología basada en la Ley de Zipf-Mandelbrot, que realiza diagnósticos objetivos de la dinámica cardíaca. Material y Métodos: Se realizó un estudio ciego con 80 registros Holter, 20 normales y 60 con hallazgos patológicos. El software organizó de manera jerárquica las frecuencias cardíacas mediante las frecuencias de aparición en rangos de 15 lat/min, linealizó los datos y obtuvo la dimensión fractal estadística, lo cual permitió la realización del análisis de complejidad. Resultados: La dimensión fractal estadística de los registros Holter normales se halló entre 0,720 y 0,913, y exhibió valores entre 0,454 y 0,665 en los registros Holter anormales. Se encontró un coeficiente Kappa de 1, y valores de especificidad y sensibilidad de 100%. Conclusiones: Se confirmó la utilidad clínica del software que automatiza la metodología fundamentada en La ley de Zipf-Mandelbrot, el cual permitió evaluar el comportamiento de los sistemas cardíacos normales y agudos.

ABSTRACT Introduction: The Zipf-Mandelbrot law allowed the development of a methodology that makes quantitative distinctions between acute and normal cardiac dynamics in an objective and reproducible way. Objective: To confirm the diagnostic capacity and clinical utility of the software that automates a methodology based on the Zipf-Mandelbrot law that performs objective diagnoses of the cardiac dynamics. Material and Methods: A blind study was performed with 80 Holter records, 20 normal and 60 with pathological findings. The software organized heart rates in a hierarchical way through their frequencies of occurrence in ranges of 15 beats per min, linearized data, and obtained statistical fractal dimension which allowed the realization of the complexity analysis. Results: The statistical fractal dimension of the normal Holter records was found between 0,720 and 0,913, and exhibited values ​​between 0,454 and 0,665 in the abnormal Holter records. A Kappa coefficient of 1, and specificity and sensitivity values ​​of 100% were found. Conclusions Methods: The clinical utility of the Software that automates the methodology based on the Zipf-Mandelbrot law was confirmed, which allowed to evaluate the behavior of normal and acute cardiac systems.

Predicción de muertes por lesiones de tráfico en Ibagué Colombia con caminata al azar probabilista / Prediction of deaths from road traffic injuries in Ibague Colombia with probabilistic random walk

Resumen Introducción: El análisis del comportamiento de la dinámica de epidemia como son el dengue y malaria en Colombia ha llevado al diseño de nueva metodología de carácter predictivo, las cuales establecen órdenes matemáticos subyacentes ante una aparente impredecibilidad de estos comportamientos. Objetivo: Confirmar la aplicabilidad de la metodología desarrollada para predecir la dinámica de la tasa de muertes por lesiones de tránsito en Ibagué Colombia para el año 2010, a partir de la caminata al azar probabilista. Metodología: Se realizó un análisis físico y matemático del de la dinámica de la tasa muertes por lesiones de tránsito en Ibagué, a partir del establecimiento de un espacio total de probabilidades con el cual se puede establecer el evento más probable en relación a los aumentos y disminuciones consecutivas anuales. Finalmente, el análisis geométrico y probabilista de esta dinámica permitió predecir la tasa del número de muertes por lesiones de tránsito para el año 2010 en Ibagué. Resultados: Para el año 2010 el DANE reporto que el número de muertes por lesiones causadas por el tránsito representa una tasa de 20,9 por cada 100.000 habitantes, el valor predicho fue de 23,2, presentado un porcentaje de acierto con la aplicación de la metodología del 90,2 %. Conclusiones: Se estableció un orden acausal probabilista para el comportamiento de la dinámica de muertes por lesiones causadas por el tránsito en Ibagué, con lo cual fue posible confirmar la aplicabilidad de la metodología y predecir el número de estas muertes para el año 2010.

Abstract Introduction: Behavioral analysis of the dynamics of epidemics such as dengue and malaria in Colombia has led to the design of new methodology of predictive character, which provides underlying mathematical commands to an apparent unpredictability of these behaviors. Objective: To confirm applicability of the methodology developed to predict the dynamics of death rate from road traffic injuries in Ibague Colombia for 2010, from the probabilistic random walk. Methodology: A physicist and mathematician of the dynamics of the death rate from road traffic injuries in Ibague, from the establishment of a complete probability space with which to establish the most probable event related to increases and consecutive declines analysis was performed annually. Finally, the geometric and probabilistic analysis of this dynamic allowed predicting the rate of deaths from road traffic injuries in 2010 in Ibague. Results: For 2010, the DANE reported that the number of deaths from road traffic injuries represents a rate of 20.9 per 100,000 inhabitants, the predicted value was 23.2, showing a success rate with implementing the methodology of 90,2 %. Conclusions: A probabilistic acausal order for the dynamic behavior of deaths from road traffic injuries in Ibague, which was possible to confirm the applicability of the methodology and predict the number of such deaths for 2010 was established.

Evaluación de cardiología normal y patológica. Sistemas que utilizan la ley de Zipf-Mandelbrot / Evaluation of normal and pathological cardiac systems using the Zipf-Mandelbrot law

Introducción: con base en la ley de Zipf-Mandelbrot, fue desarrollado un método capaz de evaluar la complejidad de los sistemas cardiacos y diferenciar normalidad de enfermedad aguda. Objetivo: corroborar la utilidad y capacidad diagnóstica de la metodología fundamentada en la ley de Zipf-Mandelbrot en la distinción de dinámicas cardiacas normales y patológicas. Métodos: fue realizado un estudio ciego con 70 registros electrocardiográficos, 20 normales y 50 patológicos. Las frecuencias cardiacas fueron organizadas jerárquicamente a partir de las frecuencias de aparición en rangos de a 15 lat/min. Posteriormente, se desarrolló una linealización de los datos, obteniendo la dimensión fractal estadística. Luego, se realizó el análisis de complejidad. Resultados: la dimensión fractal estadística de las dinámicas normales estuvo entre 0,7149 y 0,9788. Este valor se encontró entre 0,4280 y 0,6707 para dinámicas patológicas. Se obtuvieron los más altos valores de sensibilidad, especificidad y concordancia diagnóstica. Conclusiones: fue corroborada la capacidad diagnóstica de la ley de Zipf-Mandelbrot en la evaluación del comportamiento de las dinámicas cardiacas, observándose una disminución de la complejidad en las dinámicas patológicas

Introduction: based on the Zipf-Mandelbrot law, it was developed a method capable of evaluating the complexity of cardiac systems and differentiating normality from disease. Objective: to corroborate the utility and diagnostic capacity of a methodology based on the Zipf-Mandelbrot law in the distinction of normal and pathological cardiac dynamics. Methods: a blinded study was performed with 70 electrocardiographic records; of those 20 were normal and 50 were pathological. Heart rates were organized hierarchically by the occurrence frequencies in ranges of 15 lat / min. Subsequently, a linearization of the data was developed, obtaining the statistical fractal dimension. Then, the analysis of complexity was performed. Results: the statistical fractal dimension of the normal dynamics was between 0, 7149 and 0, 9788. This value was found between 0,4280 and 0,6707 for pathological dynamics. There were obtained the highest values of sensitivity, specificity and diagnostic agreement.Conclusions: it was corroborated the diagnostic capacity of the Zipf-Mandelbrot law in the evaluation of the cardiac systems behavior, observing a decrease of the complexity in the pathological dynamics.