Identificação e quantificação do cristal violeta em aguardentes de mandioca (tiquira)

Tiquira is a traditional homemade alcoholic distillate produced in the Maranhão State (Brazil), gotten from cassava (Manihot esculenta, Crantz.). It can be normally found on street markets. Due to the addition of tangerine leaves, the original tiquira has a bluish color. Samples of this beverage were acquired in the local trade and analyzed from the spectroanalytical point of view. The results indicated that these drinks had been adulterated by the addition of crystal violet, a potencialy hazardous compound. The identification and quantification of crystal violet in 10 spiked samples was accomplished by UV-Vis spectrophotometry through the standard addition method. In order to verify the efficiency of the proposed method, experiments on the quantification and recovery were carried out and the results indicated a content of crystal violet in the 10-6 to 10-7 mol L-1 range.

Preparação e caracterização de substratos SERS ativos: um estudo da adsorção do cristal violeta sobre nanopartículas de prata

The structural characterization of molecules used in the sterilization of blood for transfusions, such as crystal violet (CV), is relevant for understanding the action of these prophylactic drugs. The characterization is feasible by surface enhanced resonance Raman spectroscopy (SERRS) of CV in solution or on surfaces. The limit of detection of CV by SERRS, in the presence of colloidal particles, using 514.5 nm as excitation radiation, was found to be around 1 ppb. The characterization of CV was also made by SERS, by using different active-particles-containing substrates, proving the versatility of this technique for the study of such structures. The results suggest that the controlled production of highly efficient SERS-active substrates may allow qualitative and quantitative analysis, with high sensitivity, with potential applications in medical and environmental fields.

Estudo da sorção do corante catiônico violeta cristal por espuma de poliuretano em meio aquoso contendo dodecilsulfato de sódio

This work presents a detailed study about the sorption of crystal violet (CV) cationic dye onto polyether type polyurethane foam (PUF). The sorption process was based on the formation of an ionic-pair between cationic dye and dodecylsulfate anion (SDS), which presented high affinity by PUF. Set-up employed in the study was built up by adjusting a 200 mg cylinder of PUF to the arm of an overhead stirrer. The system was characterized in relation to equilibrium and kinetic aspects and it was modeled by employing Langmuir and Freundlich isotherms. Obtained results showed that the ratio between SDS and MB concentrations played an important role on the sorption process. According to results found it was possible to retain up to 3.4 mg of dye from 200 mL of a 5.0 x 10-5 mol L-1 CV solution containing 1.25 x 10-4 mol L-1 SDS, which represented a removal efficiency of around 92%.

Determinação de parâmetros cinéticos em fluxo com câmara de gradiente e deteção espectrofotométrica: aplicação à reação entre o violeta de cristal e o ião hidróxido

A didactic experiment is proposed aimed to extend the Flow Injection Analysis (FIA) based methodology to the area of physical chemistry/chemical reactors for undergraduate labs. Our prime objective was to describe the use of a gradient chamber for determination of the rate constant for the reaction between crystal violet and the hydroxide ion. The study was complemented by determining the effect of temperature on the rate constant. The kinetic parameters, activation energy and reaction rate constant are determined based on an assumption of rate orders. The main didactic advantages of the proposed experimental set-up are the use of less reagents, contributing to a more environmental friendly experiment. The experiment illustrates also the reduction of associated errors and time by using automated analysis owing to decreased operator manipulation.

Projecte Espai Violeta. 'Proyecto Espai Violeta'.

Se relata un proyecto desde el CP Son Oliva de Palma (Mallorca) creado para que los niños aprendan a autocontrolarse, se liberen de tensiones, se conozcan a sí mismos, aumenten su autoestima y mejoren sus relaciones personales.

A la calle... violeta.

Este proyecto retoma la iniciativa de años anteriores sobre la ciudad educadora. Los objetivos son desarrollar un sistema de trabajo en la formación de educadoras-es; profundizar en el debate sobre los elementos sexistas en la vida cotidiana y su incidencia en los niños-as de Fuenlabrada; ensayar propuestas educativas para evitar posturas discriminatorias; y ampliar los intercambios y la participación de los colectivos que trabajan con la infancia. La metodología se basa en la utilización de espacios públicos donde jueguen juntos niños y niñas, observando sus conductas. También se analiza el papel de ambos sexos en los medios de comunicación, en la casa y en los centros educativos. Todo ello se completa con talleres de actividades coeducativas, mesas redondas y charlas-coloquio. La valoración resalta el apoyo recibido por el profesorado de Educación Infantil del Colegio Público Greenpeace, la asesora del CPR de Fuenlabrada, dos técnicas en ludotecas, así como todo el alumnado de la especialidad de Jardín de Infancia. Hay propuestas de continuidad dirigidas a la multiculturalidad, análisis de la violencia y encuentros solidarios. Se adjunta programación de actividades..

La niña en el cine Ecuador 2008 a 2015. En el nombre de la hija de Tania Hermida; En espera de Gabriela Calvache; Domingo Violeta, Ánima, Nuca y Alba de Ana Cristina Barragán

La niña ha sido representada en el cine ecuatoriano de 2008 a 2015, con carácter protagónico, en seis películas -dos largometrajes y cuatro cortometrajes-, todas en el género de la ficción cinematográfica y en todos los casos escritas y dirigidas por mujeres. Descubrir las huellas dejadas por estas obras en sus representaciones es el objetivo central de esta investigación que se limita a seis películas cuya protagonista es una niña. Huellas de la expresión artística contra-hegemónica y liberadora de la persona, sujeto de derechos y agente social que son las niñas, en relación a los imaginarios y construcciones sociales que los medios de comunicación así como el arte permiten reforzar o replantear. La investigación teórica, entrevistas a profundidad y el análisis de la imagen han sido los métodos, técnicas e instrumentos utilizados a fin de lograr los necesarios referentes, insumos y criterios para lograr una mirada integral a partir de las evidencias particulares que las autoras y sus obras nos dejan. Así se ha logrado una aproximación a la representación de la niña que las autoras han hecho en sus películas, respondiendo a sus propias experiencias de vida y a la necesidad de expresar libremente sus emociones y sentimientos.

Chromatic characteristics and color-related phenolic composition of Brazilian young red wines made from the hybrid grape cultivar BRS Violeta (BRS Rúbea×IAC 1398-21)

The color characteristics and the phenolic composition related to color of young red wines elaborated with the hybrid grape cultivar BRS Violeta, developed for its adaptation to sub-tropical climates in Brazil, have been studied. These wines are characterized with a deep red-purplish color, reaching color intensity averaging 24 units. In spite of being young red wines elaborated with short maceration time, their content in total polyphenols was very high (around 3692. mg/L, as gallic acid equivalents), especially when compared to similar Vitis vinifera young red wines. Within polyphenols, anthocyanins predominated (around 2037. mg/L, as malvidin 3,5-diglucoside equivalents) and they were almost exclusively anthocyanidin 3,5-glucosides (ca. 97%), mainly built from B-ring tri-substituted anthocyanidins (delphinidin. >. petunidin. ≈. malvidin) and having high proportion of p-coumaroylated derivatives (ca. 28%) that confer higher stability. The content of hydroxycinnamic acid derivatives was also remarkable (ca. 95. mg/L, as caffeic acid equivalents) and unknown glucose derivatives of p-coumaric acid accounted for ca. 42% of total HCAD. Finally, these found flavonols were mainly based on myricetin whereas kaempferol derivatives were missing, their total content being within the ranges usually found for V. vinifera wines, but reaching their top values (ca. 91. mg/L, as quercetin 3-glucoside equivalents). All the aforementioned data suggest that Violeta wine could be considered an important dietary source of healthy polyphenols with a moderate alcoholic content (ca. 11.6%). © 2013 Elsevier Ltd.

Phenolic composition of the berry parts of hybrid grape cultivar BRS Violeta (BRS Rubea×IAC 1398-21) using HPLC-DAD-ESI-MS/MS

The grape is considered a major source of phenolic compounds when compared to other fruits and vegetables, however, there are many cultivars with distinct characteristics directly linked to phenolic profile. Thus, the present study aimed to identify and quantify, for the first time and in detail, the phenolic compounds present in the skin, flesh and seeds of BRS Violeta grape berry using combination of SPE methodologies and analytical HPLC-DAD-ESI-MS/MS. The study was extended to the different berry parts and the most important grape and wine phenolic families, and has revealed interesting features. Violeta grape has a very thick skin (46% of grape weight) that accumulated the most of grape phenolic compounds: great amount of anthocyanins (3930. mg/kg, as malvidin 3,5-diglucoside), together with also important amounts of flavonols (150. mg/kg, as quercetin 3-glucoside), hydroxycinnamic acid derivatives (HCAD; 120. mg/kg, as caftaric acid), and proanthocyanidins (670. mg/kg, as (+)-catechin); in contrast, it seems to be a low resveratrol producer. Violeta grape seeds accounted for similar proportions of low molecular weight flavan-3-ols (mainly monomers; 345. mg/kg, as (+)-catechin) and proanthocyanidins (480. mg/kg, as (+)-catechin). Violeta grape is a teinturier cultivar, but it only contained traces of anthocyanins and low amounts of all the other phenolic types in its red-colored flesh. The anthocyanin composition of Violeta grape was dominated by anthocyanidin 3,5-diglucosides (90%). Within flavonols, myricetin-type predominated and kaempferol-type was missing. In addition to expected hydroxycinnamoyl-tartaric acids, several isomeric esters of caffeic and p-coumaric acids with hexoses were tentatively identified, accounting for relevant proportions within the pool of HCAD. Although pending of further confirmation over successive vintages, the aforementioned results suggest that BRS Violeta grape cultivar could be considered an interesting candidate for the elaboration of highly colored and antioxidant-rich grape juices and wines. © 2013 Elsevier Ltd.

Aging of red wines made from hybrid grape cv. BRS Violeta: Effects of accelerated aging conditions on phenolic composition, color and antioxidant activity

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Reseña de la tesis de Violeta Vidal. "Una aproximación al movimiento por la semilla campesina de Misiones". En: LaRivada, V. 2, n° 2

el trabajo de tesis de licenciatura en antropología social de Vidal titulado “Una aproximación al movimiento por la semilla campesina de Misiones” aborda un tema central en una provincia como Misiones, donde el concepto de desarrollo sustentable es “leitmotiv” de muchas intervenciones promovidas por poblaciones locales, ONGs, agencias gubernamentales e incluso empresas privadas. El objetivo de aunar conservación con desarrollo en la gestión de recursos naturales incluye en la actualidad tanto a territorios, poblaciones humanas, como a diversas especies animales y vegetales, tal es el caso de las semillas, objeto de esta investigación de tesis

He encontrado una nueva forma de ser humano : La escritura del cuerpo como intervención política y cultural en la poética de Violeta Parra

La pregunta acerca de la relación entre escritura moderna, ligada a una firma, a una imagen de autor, y el acervo folklórico con el que dialoga, aún comporta una exigencia crítica en torno a la obra de Violeta Parra. La relación entre Décimas autobiográficas y Cantos folklóricos chilenos, desde una perspectiva que pone en el centro la escritura como experiencia, puede cuestionar el aspecto teleológico con que se ha leído ese diálogo. El punto de análisis será esa zona inestable de las huellas de escritura, la operación sobre el acervo colectivo. El cuerpo, como ausencia y metáfora, es uno de los puntos de intensidad donde esas huellas textuales de la tradición pugnan por cobrar sentido; pero esos espacios, para usar una palabra parriana, 'mudan' constantemente

He encontrado una nueva forma de ser humano : La escritura del cuerpo como intervención política y cultural en la poética de Violeta Parra

La pregunta acerca de la relación entre escritura moderna, ligada a una firma, a una imagen de autor, y el acervo folklórico con el que dialoga, aún comporta una exigencia crítica en torno a la obra de Violeta Parra. La relación entre Décimas autobiográficas y Cantos folklóricos chilenos, desde una perspectiva que pone en el centro la escritura como experiencia, puede cuestionar el aspecto teleológico con que se ha leído ese diálogo. El punto de análisis será esa zona inestable de las huellas de escritura, la operación sobre el acervo colectivo. El cuerpo, como ausencia y metáfora, es uno de los puntos de intensidad donde esas huellas textuales de la tradición pugnan por cobrar sentido; pero esos espacios, para usar una palabra parriana, 'mudan' constantemente