Reactivity of 2-acetylhydrazonemethyl-l -arylimidazole with reducing agents

La hidrogenación catalítica de los compuestos 1 origina mayoritariamente el producto resultante de la hidrogenolisis del enlace C=N y sólo se obtienen bajos rendimientos de las hidracidas 2 al utilizar Pd(C) como catalizador. La reducción con AILiH4 de la rinde, para el estereoisómero Z, la hidracida 2a; mientras que el estereoisómero E conduce por hidrogenolisis a los compuestos 4a y 5a.Catalytic hydrogenation of compounds 1 led mainly to the products resulting of the hydrogenolysis of the bond C=N, while the hydrazides 2 were obtained in small yields using Pd(C) as catalyst. Reduction of la with AILiH. yielded the hydrazide 2a for the Z stereoisomer and the products 4a and 5a for the E stereoisomer by hydrogenolysis

Constituyentes del aceite esencial de Lavándula Lanata Boiss

We studied the essential oil of Lavandula Lanata Boiss, in which thirty four substances were identified, camphor, lavandulol and 3-octanone being the most abundant of them. The percentages of these compounds were found to vary considerably depending on the vegetative stage on which the plant was collected.Hemos estudiado la composición química del aceite esencial de Lavandula Lanata Boiss, habiendo identificado treinta y cuatro sustancias, de las cuales, lavandulol, 3-octanona y alcanfor son las más abundantes. Se ha encontrado que el porcentaje de estos componentes varía considerablemente en función de la época de recogida de la planta

Reactividad de 2-acetilhidrazonometil-1-arilimidazol frente a agentes reductores

Catalytic hydrogenation of compounds 1 led mainly to the products resulting of the hydrogenolysis of the bond C=N, while the hydrazides 2 were obtained in small yields using Pd(C) as catalyst. Reduction of la with AlLiH4 yielded the hydrazide 2a for the Z stereoisomer and the products 4a and 5a for the E stereoisomer by hydrogenolysis.La hidrogenación catalítica de los compuestos 1 origina mayoritariamente el producto resultante de la hidrogenolisis del enlace C=N y sólo se obtienen bajos rendimientos de las hidracidas 2 al utilizar Pd(C) como catalizador. La reducción con AlLiH4 de la rinde, para el estereoisómero Z, la hidracida 2a; mientras que el estereoisómero E conduce por hidrogenolisis a los compuestos 4a y 5a

Constituyentes del aceite esencial de Lavándula Lanata Boiss

Hemos estudiado la composición química del aceite esencial de Lavandula Lanata Boiss, habiendo ·identificado treinta y cuatro sustancias, de las cuales, lavandulol, 3-octanona y alcanfor son las más abundantes. Se ha encontrado que el porcentaje de estos componentes varía considerablemente en función de la época de recogida de la planta.We studied the essential oil of Lavandula Lanata Boiss, in which thirty four substances were identified, camphor, lavandulol and 3-octanone being the most abundant of them. The percentages of these compounds were found to vary considerably depending on the vegetative stage on which the plant was collected

Mangrove forest mapping through remote sensing imagery: study case for Buenaventura, Colombia

[EN] Mangroves are plant communities of high ecological and economic importance for coastal regions. This investigation provides a methodology for mapping Mangrove forests through remote sensing images in a semidetail scale (1:25,000) in a sector of the municipality of Buenaventura, Colombia. A Sentinel 2 image and 2017 highresolution ortophotomosaic of the municipality were used for the mangrove cartography, using QGIS software, spectral analysis was performed and supervised classification was established using Maximum Likelihood algorithm. Results shown that mangrove is the most representative cover in the study area whit 7,264.21 ha in total extension (59.21% of total area), the development classification got a thematic accuracy of 80% and 0.70 in Kappa index. The used methodology can be used as an academic and research reference for mangrove semi-detail mapping in the world.[ES] Los manglares son comunidades vegetales de alta importancia ecología y económica para las regiones costeras. La presente investigación proporciona un método para determinar la cartografía de bosques manglar mediante imágenes de sensores remotos a escala 1:25.000 en un sector del municipio de Buenaventura, Colombia; para la cartografía de bosques de manglar se empleó una imagen satelital Sentinel 2 y una ortofotografía de alta resolución del año 2017; usando el software libre QGIS, se realizó los análisis espectrales, se estableció una clasificación supervisada mediante el algoritmo de máxima verosimilitud. Los resultados obtenidos muestran que la cobertura de manglar es la de mayor representatividad en el área de estudio con una extensión total de 7.264,21 ha (59,21% del área total), la clasificación desarrollada presentó una exactitud temática global de 80% e índice de Kappa de 0,70. El método empleado sirve como un referente sobre la cartografía de bosques de manglar en el mundo.Perea-Ardila, MA.; Oviedo-Barrero, F.; Leal-Villamil, J. (2019). Cartografía de bosques de manglar mediante imágenes de sensores remotos: estudio de caso Buenaventura, Colombia. Revista de Teledetección. (53):73-86. https://doi.org/10.4995/raet.2019.11684SWORD73865

Using machine learning to identify common flaws in CAPTCHA design: FunCAPTCHA case analysis

Human Interactive Proofs (HIPs 1 or CAPTCHAs 2) have become a first-level security measure on the Internet to avoid automatic attacks or minimize their effects. All the most widespread, successful or interesting CAPTCHA designs put to scrutiny have been successfully broken. Many of these attacks have been side-channel attacks. New designs are proposed to tackle these security problems while improving the human interface. FunCAPTCHA is the first commercial implementation of a gender classification CAPTCHA, with reported improvements in conversion rates. This article finds weaknesses in the security of FunCAPTCHA and uses simple machine learning (ML) analysis to test them. It shows a side-channel attack that leverages these flaws and successfully solves FunCAPTCHA on 90% of occasions without using meaningful image analysis. This simple yet effective security analysis can be applied with minor modifications to other HIPs proposals, allowing to check whether they leak enough information that would in turn allow for simple side-channel attacks

Inhibidores selectivos de la monoamino oxidasa. 1. Hidracinas de formilimidazoles 1-sustitudos

A series of hydrazinomethylimidazole 1-sustituted was prepared and evaluated for their monoamine oxidase (MAO) inhibitory activity. In vitro testing revealed that the 1-arylimidazole derivatives were selectively inhibitors of MAO A at low concentrations.Se ha preparado una serie de hidracinometilimidazoles 1-sustituidos y estudiado su actividad IMAO. Los ensayos in vitro revelan que los 1-arilimidazoles son inhibidores selectivos de la MAO A a bajas concentraciones