Physiological responses of a halophytic shrub to salt stress by Na2SO4 and NaCl: oxidative damage and the role of polyphenols in antioxidant protection

Salt stress conditions lead to increased production of reactive oxygen species (ROS) in plant cells. Halophytes have the ability to reduce these toxic ROS by means of a powerful antioxidant system that includes enzymatic and non-enzymatic components. In this research, we used the halophytic shrub Prosopis strombulifera to investigate whether the ability of this species to grow under increasing salt concentrations and mixtures was related to the synthesis of polyphenolic compounds and to the maintenance of leaf pigment contents for an adequate photosynthetic activity. Seedlings of P. strombulifera were grown hydroponically in Hoagland's solution, gradually adding Na2SO4 and NaCl separately or in mixtures until reaching final osmotic potentials of −1, −1.9 and −2.6 MPa. Control plants were allowed to develop in Hoagland's solution without salt. Oxidative damage in tissues was determined by H2O2 and malondialdehyde content. Leaf pigment analysis was performed by high-performance liquid chromatography with ultraviolet, and total phenols, total flavonoids, total flavan-3-ols, condensed tannins, tartaric acid esters and flavonols were spectrophotometrically assayed. Treatment with Na2SO4 increased H2O2 production and lipid peroxidation in tissues and induced a sharp increase in flavonoid compounds (mainly flavan-3-ols) and consequently in the antioxidant activity. Also, Na2SO4 treatment induced an increased carotenoid/chlorophyll ratio, which may represent a strategy to protect photosystems against photooxidation. NaCl treatment, however, did not affect H2O2 content, lipid peroxidation, pigments or polyphenols synthesis. The significant accumulation of flavonoids in tissues under Na2SO4 treatment and their powerful antioxidant activity indicates a role for these compounds in counteracting the oxidative damage induced by severe salt stress, particularly, ionic stress. We demonstrate that ionic interactions between different salts in salinized soils modify the biochemical and morpho-physiological responses of P. strombulifera plants to salinity.Fil: Reginato, Mariana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquímicas y Naturales. Cátedra de Fisiología Vegetal; ArgentinaFil: Castagna, Antonella. Università degli Studi di Pisa; ItaliaFil: Furlan, Ana Laura. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; ArgentinaFil: Castro, Stella Maris. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; ArgentinaFil: Ranieri, Annamaria. Università degli Studi di Pisa; ItaliaFil: Luna, Maria Virginia. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquímicas y Naturales. Cátedra de Fisiología Vegetal; Argentin

Physiological and biochemical responses to drought stress and subsequent rehydration in the symbiotic association peanut-Bradyrhizobium sp

Drought stress is one of the most important environmental factors that regulate plant growth and development and limit its production. Peanut (Arachis hypogaea L.) is an agriculturally valuable plant with widespread distribution in the world serving as a subsistence food crop as well as a source of various food products. The aims of this work were to evaluate growth and nodulation as well as some physiological and biochemical stress indicators in response to drought stress and subsequent rehydration in the symbiotic association peanut-Bradyrhizobium sp. SEMIA6144. Drought stress affected peanut growth reducing shoot dry weight, nodule number, and dry weight as well as nitrogen content, but root dry weight increased reaching major exploratory surface. Besides, this severe water stress induced hydrogen peroxide production associated with lipid and protein damage; however, the plant was able to increase soluble sugar and abscisic acid contents as avoidance strategies to cope with drought stress. These physiological and biochemical parameters were completely reversed upon rehydration, in a short period of time, in the symbiotic association peanut-Bradyrhizobium sp. Thus, the results provided in this work constitute the initial steps of physiological and biochemical responses to drought stress and rehydration in this nodulated legume.Fil: Furlan, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; ArgentinaFil: Llanes, Analia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; ArgentinaFil: Luna, Maria Virginia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Castro, Stella Maris. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentin

Micrographic parameters of primary stem, flower, fruit, and seed of Terminalia australis

Terminalia australis Cambess (Combretaceae), known as palo amarillo, is an arboreal species, less frequently shrubby, and native of Brazil, Paraguay, Uruguay, and Argentina. Antimicrobial activity was verified through investigations carried out with aqueous extracts from leaves. The purpose of the current work is to study the exo-endomorphology of the aerial organs (primary stem, flower, fruit, and seed) of the mentioned species in order to establish micrographic parameters for a future pharmacopeic monograph. Fresh and dry materials were studied. Sections and macerations were obtained. Designs were obtained with light microscope equipped with a drawing tube, and photomicrographs were generated with scanning electron microscope. Numerical values were determined: lineal magnitude for the species that are presented together with the data typical of the histoanatomy of the aerial organs.Facultad de Ciencias ExactasLaboratorio de Referencia de Análisis Micrográficos de Plantas Medicinales, Alimenticias y Tóxica

A elaboração e avaliação de um sistema de ensino a distância em oftalmologia

INTRODUCTION: Web-based e-learning is a teaching tool increasingly used in many medical schools and specialist fields, including ophthalmology. AIMS: this pilot study aimed to develop internet-based course-based clinical cases and to evaluate the effectiveness of this method within a graduate medical education group. METHODS: this was an interventional randomized study. First, a website was built using a distance learning platform. Sixteen first-year ophthalmology residents were then divided into two randomized groups: one experimental group, which was submitted to the intervention (use of the e-learning site) and another control group, which was not submitted to the intervention. The students answered a printed clinical case and their scores were compared. RESULTS: there was no statistically significant difference between the groups. CONCLUSION: We were able to successfully develop the e-learning site and the respective clinical cases. Despite the fact that there was no statistically significant difference between the access and the non access group, the study was a pioneer in our department, since a clinical case online program had never previously been developed.INTRODUÇÃO: O ensino a distância pela Internet é uma ferramenta de educação cada vez mais utilizada em muitas faculdades de medicina e áreas de medicina especializadas, inclusive a oftalmologia. OBJETIVOS: Este estudo piloto teve como objetivo elaborar casos clínicos baseados no curso online e avaliar a eficácia deste método num grupo de estudantes de pós-graduação de medicina. MÉTODOS: foi um estudo de intervenção randomizado. Em primeiro lugar, um website foi construído usando uma plataforma de ensino à distância. Dezesseis residentes de oftalmologia do primeiro ano então foram divididos em dois grupos aleatórios: um grupo experimental, o qual foi submetido à intervenção (uso do site de ensino a distância) e outro grupo de controle, que não foi submetido à intervenção. Os alunos responderam a um caso clínico impresso e seus resultados foram comparados. RESULTADOS: não houve diferença estatisticamente significativa entre os grupos. CONCLUSÃO: Conseguimos desenvolver com sucesso o website de ensino a distância e os respectivos casos clínicos. Apesar do fato de que não houve diferença estatisticamente significativa entre o grupo com acesso e o grupo sem acesso, o estudo foi pioneiro no nosso departamento, uma vez que nunca havia sido desenvolvido anteriormente um programa online de casos clínicos.9610

First records of leucism in small rodents for Argentina

Leucism appears in various groups of vertebrates, although it is rare in mammals. For Argentina, we do not know of any documented registry for small rodents. The objective of our work is to report the first cases of leucism in cricetid rodents in the Puna Desert of Argentina. Field work was carried out in the Multiple Use Provincial Reserve Don Carmelo (San Juan, Argentina), located in the Puna Desert. The animals were captured in 9 grids formed by 36 Sherman-type traps, established in plots located between 3.100 and 3.300 m, in the years 2013-2014. We recorded 6 cases of leucism in 3 species of cricetids: Eligmodontia sp. (n = 3), Abrothrix andina (n = 2), and Phyllotis xanthopygus (n = 1). This work represents the first report of cases of leucism in small mammals from Argentina. The cases in the studied population could be due to the low gene flow imposed by the high environmental severity of an extreme desert, probably related to genetic causes derived from climatic and ecological factors, as these are non-anthropized environments.Fil: Beninato Bustamante, Veronica Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Rivero Castro, Gustavo Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Pérez, Mauricio Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Borghi, Carlos Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Giannoni, Stella Maris. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentin

Controle visual em crianças com dislexia do desenvolvimento

PURPOSE: To assess binocular control in children with dyslexia. METHODS: Cross-sectional study with 26 children who were submitted to a set of ophthalmologic and visual tests. RESULTS: In the dyslexic children less eye movement control in voluntary convergence and unstable binocular fixation was observed. CONCLUSION: The results support the hypothesis that developmental dyslexia might present deficits which involve the magnocellular pathway and a part of the posterior cortical attentional network.OBJETIVO: Avaliar o controle binocular em crianças com dislexia. MÉTODOS: Estudo transversal do qual participaram 26 crianças, nas quais foram aplicadas uma série de exames oftalmológicos e visuais. RESULTADOS: Nas crianças com dislexia observou-se controle menor na convergência voluntária e na estabilidade da fixação binocular. CONCLUSÃO: Os resultados apóiam a hipótese de que na dislexia do desenvolvimento podem ocorrer déficits que envolvem a via visual magnocelular e uma parte da rede cortical posterior da atenção.83784

Educación ambiental en barrios periféricos: diagnóstico y primeros pasos

La educación ambiental (EA) es un proceso de concientización y promoción social para la resolución de problemas ambientales en pos del desarrollo sustentable, dirigido a todos los sectores de la población, incluyendo el sistema educativo formal, el no formal y la comunidad toda. Es decir, consiste en trasmitir conocimientos sobre el ambiente e involucrar a la ciudadanía como agente transformador y partícipe en el proceso de toma de decisiones. Un propósito fundamental de la EA es lograr que tanto los individuos como las colectividades comprendan la naturaleza compleja del ambiente, resultante de la interacción de sus diferentes aspectos: físicos, biológicos, sociales, culturales y económicos, entre otros. Éste promueve el desarrollo de una percepción más clara en referencia a la responsabilidad sobre las problemáticas ambientales (Durán, 2002). Por su parte, Richard (2004) define a la EA como la formación del ser humano en actitudes, valores, destrezas y habilidades para la comprensión de las relaciones entre ambiente y sociedad, los problemas y situaciones derivados de dichas relaciones y la adecuada aplicación de este conocimiento en el manejo y planificación sostenible de los recursos naturales y culturales con plena conciencia y respeto entre sociedades Dichas problemáticas más acuciantes están generalmente asociadas a los sectores sociales con mayor vulnerabilidad. El presente proyecto se implementa inicialmente en el barrio Nuevo Golf, lindante a las áreas rurales del sector sur de la ciudad de Mar del Plata, para luego replicarlo en otras áreas periurbanas.Publicado en: "Geografías del presente para construir el mañana: miradas geográficas que contribuyen a leer el presente"

Modelado estadístico de la producción de vinos tintos finos

En la provincia de San Juan, Argentina, la elaboración del vino es una de las actividades económicas más importantes. Para es- te tipo de industria, es de fundamental importancia predecir la cantidad de producción en función de la cantidad de materia pri- ma. El objetivo de este trabajo es la obtención de un modelo que relacione los kilogramos de uva molidos con los litros de vino producidos. Dicho modelo se usará para realizar predicciones de valores futuros, puntuales y por intervalos de confianza para un nivel determinado de molienda. A tal fin, se trabajó con datos obtenidos de una bodega ubicada en la provincia de San Juan. En primer lugar, se calculó el coeficiente de correlación muestral y se realizó un diagrama de dispersión, el cual indicó u- na marcada relación lineal entre los litros de vino obtenidos y los kilogramos de uva molidos. Posteriormente, se adoptaron dos modelos lineales y se efectuó el análisis de varianza, ya que los datos provenían de poblaciones normales con igual varianza. De este análisis se desprendió el modelo más adecuado, el cual fue validado con valores experimentales, obteniendo una bue- na aproximación de estos.Producing wine is a very important economic activity in the province of San Juan in Argentina; it is therefore most important to predict production regarding the quantity of raw material needed. This work was aimed at obtaining a model relating kilograms of crushed grape to the litres of wine so produced. Such model will be used for predicting precise future values and confidence intervals for determined quantities of crushed grapes. Data from a vineyard in the province of San Juan was thus used in this work. The sampling coefficient of correlation was calculated and a dispersion diagram was then constructed; this indicated a li- neal relationship between the litres of wine obtained and the kilograms of crushed grape. Two lineal models were then adopted and variance analysis was carried out because the data came from normal populations having the same variance. The most appropriate model was obtained from this analysis; it was validated with experimental values, a good approach being obtained

Targeting redox metabolism of the maize-Azospirillum brasilense interaction exposed to arsenic-affected groundwater

Arsenic in groundwater constitutes an agronomic problem due to its potential accumulation in the food chain. Among the agro-sustainable tools to reduce metal(oid)s toxicity, the use of plant growth-promoting bacteria (PGPB) becomes important. For that, and based on previous results in which significant differences of As translocation were observed when inoculating maize plants with Az39 or CD Azospirillum strains, we decided to decipher the redox metabolism changes and the antioxidant system response of maize plants inoculated when exposed to a realistic arsenate (AsV) dose. Results showed that AsV caused morphological changes in the root exodermis. Photosynthetic pigments decreased only in CD inoculated plants, while oxidative stress evidence was detected throughout the plant, regardless of the assayed strain. The antioxidant response was strain-differential since only CD inoculated plants showed an increase in superoxide dismutase, glutathione S-transferase (GST), and glutathione reductase (GR) activities while other enzymes showed the same behavior irrespective of the inoculated strain. Gene expression assays reported that only GST23 transcript level was upregulated by arsenate, regardless of the inoculated strain. AsV diminished the glutathione (GSH) content of roots inoculated with the Az39 strain, and CD inoculated plants showed a decrease of oxidized GSH (GSSG) levels. We suggest a model in which the antioxidant response of the maize-diazotrophs system is modulated by the strain and that GSH plays a central role acting mainly as a substrate for GST. These findings generate knowledge for a suitable PGPB selection, and its scaling to an effective bioinoculant formulation for maize crops exposed to adverse environmental conditions.Fil: Peralta, Juan Manuel. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Investigaciones Agrobiotecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Agrobiotecnologicas.; ArgentinaFil: Bianucci, Eliana Carolina. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Investigaciones Agrobiotecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Agrobiotecnologicas.; ArgentinaFil: Romero Puertas, María C.. Consejo Superior de Investigaciones Científicas. Estación Experimental del Zaidín; EspañaFil: Furlan, Ana Laura. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Investigaciones Agrobiotecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Agrobiotecnologicas.; ArgentinaFil: Castro, Stella Maris. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Investigaciones Agrobiotecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Agrobiotecnologicas.; ArgentinaFil: Travaglia, Claudia Noemi. Universidad Nacional de Rio Cuarto. Facultad de Cs.exactas Fisicoquimicas y Naturales. Instituto de Investigaciones Agrobiotecnologicas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Agrobiotecnologicas.; Argentin

Micrographic parameters of primary stem, flower, fruit, and seed of Terminalia australis

Terminalia australis Cambess (Combretaceae), known as palo amarillo, is an arboreal species, less frequently shrubby, and native of Brazil, Paraguay, Uruguay, and Argentina. Antimicrobial activity was verified through investigations carried out with aqueous extracts from leaves. The purpose of the current work is to study the exo-endomorphology of the aerial organs (primary stem, flower, fruit, and seed) of the mentioned species in order to establish micrographic parameters for a future pharmacopeic monograph. Fresh and dry materials were studied. Sections and macerations were obtained. Designs were obtained with light microscope equipped with a drawing tube, and photomicrographs were generated with scanning electron microscope. Numerical values were determined: lineal magnitude for the species that are presented together with the data typical of the histoanatomy of the aerial organs.Facultad de Ciencias ExactasLaboratorio de Referencia de Análisis Micrográficos de Plantas Medicinales, Alimenticias y Tóxica