Degradación de fenolftaleína por medio de la reacción Fenton con nanoestructuras de hierro

El agua es esencial para la vida y está presente en nuestro alrededor, en una parte importante de nuestra vida para satisfacer las necesidades del día a día y también para cumplir las funciones del cuerpo. La calidad del agua es fundamental para producir alimentos y también para producir energía. Actualmente la falta de acceso, la contaminación y el desperdicio de la misma; son desafíos que se presentan en el medio ambiente. Menos del 1% del agua de planeta es dulce y accesible para el hombre, este porcentaje puede variar dependiendo el lugar, el clima y la época del año. La ONU estima que en 40 años la demanda de agua se incrementará en un 50% debido al incremento en la población. En muchas regiones del mundo crecen las tensiones porque varios países comparten ríos y por lo tanto compiten por la misma agua, este es el caso de Egipto, Sudán y Etiopía quienes se enfrentan por el control del Nilo

Effect of the Fe Nanoparticles Generated by Pulsed Plasma in Liquid in the Catalyzed Ozone Removal of Phenolphthalein

We have synthesized, in this work, zero valent iron (ZVI) nanoparticles to improve the efficiency of degradation of phenolphthalein catalyzed by ozone in aqueous solution. The Fe nanoparticles were obtained using the pulsed plasma in liquid (PPL) method with water as the liquid medium. Such nanoparticles have a mean size of 12 nm and are composed of ~80% Fe0, while the rest are a mixture of Fe+2 and Fe+3 oxides. The degradation of phenolphthalein was carried on a glass reactor injecting a constant amount of ozone and introducing different concentrations of Fe nanoparticles to the system. When using pure ozone, the percentage of degradation of phenolphthalein measured by colorimetry after one hour of reaction was 84%. However, when Fe nanoparticles are used, such percentage can be as high as 98% in 50 minutes of reaction. Furthermore, the degradation rate constant was 0.0334 min−1 with only ozone and it can be as high as 0.0733 min−1 with Fe nanoparticles. Finally, the total mineralization of phenolphthalein was obtained by total organic carbon (TOC) determinations. It is shown that when using only ozone, we obtained a percentage of mineralization of 49% and 96% when using the highest concentration of Fe nanoparticles

Scriptorium, Nº 13, 2017 (número completo)

Como lo hacían en las escuelas catedralicias y en las universidades medievales, los maestros de nuestro tiempo guían a los estudiantes a adquirir saberes a partir de sus propios conocimientos, mediante métodos que aplican de acuerdo a la experiencia o a la concepción del mundo de cada uno de ellos. Con este bagaje los alumnos harán su propio camino a través de lecturas, investigación, reflexión crítica, etc. Nuestra idea es mostrar los trabajos iniciales, aquellos que aún gozan del cuidado y la corrección de los maestros, pero con un porcentaje de investigación, lectura y reflexión propia. En este caso ponemos a consideración de ustedes, nuestros lectores, la producción de dos grupos diferentes por su origen, por la materia que tratan y por el método utilizado, pero igualmente ricos en sus resultados. El primero de ellos es el resultado del trabajo en el marco de la Cátedra de Literatura Española I, de la carrera de Letras de la Universidad Nacional de La Pampa “Un aula abierta para la recreación imaginaria de la Edad Media” cuya propuesta parte de la idea que los alumnos elijan y lean una novela contemporánea y a través de ella analicen un tema o una problemática en relación a los textos o géneros medievales. Así veremos una mirada particular a Iacubus de Matilde Asensi, al Nombre de la rosa de Umberto Eco y a Historia del Rey Transparente de Rosa Montero. El segundo grupo de trabajos es el resultado de tres seminarios virtuales ofrecido por la Cátedra de Historia Medieval y Moderna en el marco de la Unidad de Gestión de Educación a Distancia de la Facultad de Ciencias Humanas de la Universidad Nacional del Centro de la Provincia de Buenos Aires y agrupados bajo el título de “Los desafíos de la educación a distancia al mundo preindustrial”, cuyo arco temporal abarca desde el siglo XII al XVIII y cuya temática incluye cuestiones relacionadas con la conquista de América en “Un abordaje a la Historia Natural y Moral de las Indias del jesuita José de Acosta”, con la Historia de las Mentalidades “El Miedo en el Imaginario Social de Europa Occidental” y con la Historia Social “Entre lo comunal y lo privado: las usurpaciones de comunales en la transición al capitalismo. Intereses pecheros y la actuación de la Justicia regia”.Contenido: Palabras iniciales / Cecilia Bahr -- Un aula abierta para la recreación imaginaria de la edad media / Lidia Raquel Miranda -- Las instituciones de clérigos guerreros: su representación en Iacobus y su proyección al mundo actual / Concepción Campisi -- La concepción ‘medievalesca’ en El nombre de la Rosa / Mariana Alejandra Casado -- La representación de la mujer en las letras hispánicas : de la edad media a Historia del rey transparente / Nora Melina Moyano --La historia medieval y moderna en tres seminarios virtuales : los desafíos de la educación a distancia al mundo preindustrial / Silvina Mondragón, Verónica Barragán y Javier Chimondeguy -- Un abordaje a la Historia natural y moral de las indias del jesuita José de Acosta / Margarita Fernández -- El miedo en el imaginario social de Europa occidental / Paula Daniela Cava -- Entre lo comunal y lo privado : las usurpaciones de comunales en la transición al capitalismo : intereses pecheros y la actuación de la Justicia regia / Aldana Paola Bustamante

Changes in the Proliferation of the Neural Progenitor Cells of Adult Mice Chronically Infected with <i>Toxoplasma gondii</i>

During Toxoplasma gondii chronic infection, certain internal factors that trigger the proliferation of neural progenitor cells (NPCs), such as brain inflammation, cell death, and changes in cytokine levels, are observed. NPCs give rise to neuronal cell types in the adult brain of some mammals. NPCs are capable of dividing and differentiating into a restricted repertoire of neuronal and glial cell types. In this study, the proliferation of NPCs was evaluated in CD-1 adult male mice chronically infected with the T. gondii ME49 strain. Histological brain sections from the infected mice were evaluated in order to observe T. gondii tissue cysts. Sagittal and coronal sections from the subventricular zone of the lateral ventricles and from the subgranular zone of the hippocampal dentate gyrus, as well as sagittal sections from the rostral migratory stream, were obtained from infected and non-infected mice previously injected with bromodeoxyuridine (BrdU). A flotation immunofluorescence technique was used to identify BrdU+ NPC. The scanning of BrdU+ cells was conducted using a confocal microscope, and the counting was performed with ImageJ® software (version 1.48q). In all the evaluated zones from the infected mice, a significant proliferation of the NPCs was observed when compared with that of the control group. We concluded that chronic infection with T. gondii increased the proliferation of NPCs in the three evaluated zones. Regardless of the role these cells are playing, our results could be useful to better understand the pathogenesis of chronic toxoplasmosis

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans—anteaters, sloths, and armadillos—have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths. Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the southern United States, Mexico, and Caribbean countries at the northern portion of the Neotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n = 5,941), and Cyclopes sp. have the fewest (n = 240). The armadillo species with the most data is Dasypus novemcinctus (n = 11,588), and the fewest data are recorded for Calyptophractus retusus (n = 33). With regard to sloth species, Bradypus variegatus has the most records (n = 962), and Bradypus pygmaeus has the fewest (n = 12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans data set. Please cite this data paper when using its data in publications. We also request that researchers and teachers inform us of how they are using these data

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data